gr-mcp-docs/reference/cospas-sarsat/g-series/g007.md

title	description	sidebar	documentId	series	seriesName	documentType	isLatest	issue	revision	documentDate	originalTitle
G007: Handbook On Distress Alert Messages For Rescue Coordination Centres	Official Cospas-Sarsat G-series document G007	badge text variant G note	G007	G	General	overview	true	3	3	October 2024	Handbook On Distress Alert Messages

📋 Document Information

Series: G-Series (General) Version: Issue 3 - Revision 3 Date: October 2024 Source: Cospas-Sarsat Official Documents

---

---

HANDBOOK ON DISTRESS ALERT MESSAGES FOR RESCUE COORDINATION CENTRES (RCCs), SEARCH AND RESCUE POINTS OF CONTACT (SPOCs) AND IMO SHIP SECURITY COMPETENT AUTHORITIES C/S G.007 Issue 3 – Revision 3

---

HANDBOOK ON DISTRESS ALERT MESSAGES FOR RESCUE COORDINATION CENTRES (RCCs), SEARCH AND RESCUE POINTS OF CONTACT (SPOCs) AND IMO SHIP SECURITY COMPETENT AUTHORITIES HISTORY Issue Revision Date Comments

Approved by Council (CSC-41)

Approved by Council (CSC-43)

Approved by Council (CSC-45)

Approved by Council (CSC-47)

Approved by Council (CSC-49)

Approved by Council (CSC-51)

Approved by Council (CSC-53)

Approved by Council (CSC-57)

Approved by Council (CSC-59)

Approved by Council (CSC-62)

Approved by Council (CSC-64)

Approved by Council (CSC-66)

Approved by Council (CSC-67)

Approved by Council (CSC-69)

Approved by Council (CSC-71)

TABLE OF CONTENTS Page INTRODUCTION ...................................................................................................... 1–1 1.1 Overview ........................................................................................................... 1–1 1.2 Document Organisation .................................................................................... 1–1 1.3 Cospas-Sarsat .................................................................................................... 1–1 1.4 The Cospas-Sarsat System ................................................................................ 1–2 1.5 Reference Documents ....................................................................................... 1–6 COSPAS-SARSAT BEACONS ................................................................................. 2–1 2.1 Beacon Types .................................................................................................... 2–1 2.2 Characteristics of a 406-MHz Beacon .............................................................. 2–5 2.3 The Beacon Message ........................................................................................ 2–6 2.4 Hexadecimal Identity of a 406-MHz Beacon ................................................... 2–7 2.5 Direction Finding on 406-MHz Beacons .......................................................... 2–9 2.6 Return Link Service (RLS) ............................................................................... 2–9 2.7 GNSS Positions .............................................................................................. 2–10 2.8 Beacon Registration ........................................................................................ 2–11 2.9 International Beacon Registration Database (IBRD)...................................... 2–12 2.10 Beacon Regulation .......................................................................................... 2–14 2.11 Beacon Testing ............................................................................................... 2–14 2.12 Inadvertent Alert ............................................................................................. 2–15 COSPAS-SARSAT SATELLITE SYSTEMS........................................................... 3–1 3.1 MEOSAR .......................................................................................................... 3–1 3.2 LEOSAR ........................................................................................................... 3–6 3.3 GEOSAR ........................................................................................................ 3–12 MISSION CONTROL CENTRES ............................................................................ 4–1 4.1 General Principles ............................................................................................. 4–2 4.2 MCC Messages ................................................................................................. 4–4 4.3 Alerts with Invalid or Suspect Data ................................................................ 4–11 COSPAS-SARSAT DISTRESS MESSAGES ........................................................... 5–1 5.1 Paragraph 1: Message Type .............................................................................. 5–2 5.2 Paragraph 2: Current Message Number and MCC Beacon Reference ............. 5–3

5.3 Paragraph 3: Beacon Message Information ...................................................... 5–3 5.4 Paragraph 4: Alert Position Information ........................................................... 5–8 5.5 Paragraph 5: Other Information ...................................................................... 5–12 5.6 Paragraph 6: Remarks ..................................................................................... 5–14 5.7 End of Message ............................................................................................... 5–15

EXAMPLES OF BEACON INCIDENTS 6-1 6.1 An Unlocated Detection to a Confirmed Update 6-1 6.2 From Unlocated Alert to Position Confirmation 6-7 6.3 A Position Confirmed Alert as the First Alert 6-13 6.4 A MEOSAR Alert Confirmed by a LEOSAR Alert 6-14 6.5 A Position Conflict Alert 6-16 6.6 A Notification of Country of Registration Alert 6-21 6.7 An Unresolved Doppler Position Match Alert 6-23 6.8 ELT(DT) Alerts 6-25 6.9 Cancellation Alerts 6-29 6.10 Sample SIT 985 Message with SGB Characteristics Based on TAC Number 6-30 6.11 A Ship Security Alert 6-31 6.12 An Alert with an Invalid Beacon Message 6-34 6.13 An Alert with a Satellite Manoeuvre Warning 6-34 6.14 An Interferer Alert 6-36

FREQUENTLY ASKED QUESTIONS 7-1 LIST OF ANNEXES Page Annex A: Acronyms and Terminology ................................................................................ A-1 Annex B: List of MID (Country) Codes .............................................................................. B-1 Annex C: Cospas-Sarsat Data Distribution Regions ........................................................... C-1 Annex D: How to Use the IBRD ......................................................................................... D-1

LIST OF FIGURES Page Figure 1.1: An Overview of the Cospas-Sarsat Beacon Detection System ........................... 1–3 Figure 1.2: A Sample SIT 185 Message ................................................................................ 1–6 Figure 2.1: Distress Beacon Types ......................................................................................... 2–1 Figure 2.2: The GISIS Maritime Security Website Interface................................................. 2–4 Figure 2.3: A Ship Security Alert System (SSAS) Beacon ................................................... 2–4 Figure 2.4: Beacon with Hex ID 3EF42AF43F81FE0 ........................................................... 2–8 Figure 2.5: Decode of Beacon 3EF42AF43F81FE0 .............................................................. 2–9 Figure 2.6: Information Graphic on Sources of False Alerts ............................................... 2–15 Figure 3.1: A Schematic View of the Galileo Constellation .................................................. 3–2 Figure 3.2: Footprint of a GPS MEOSAR Satellite ............................................................... 3–2 Figure 3.3: An Overview of the MEOSAR System ............................................................... 3–3 Figure 3.4: DOA Location Error Smaller than the Associated Expected-Accuracy Value .. 3–4 Figure 3.5: Additional Expected-Accuracy-Related Boundary ............................................. 3–5 Figure 3.6: Probability of the Actual Beacon Location Being Within the Expected Accuracy- Radius and Two-Times Expected Accuracy-Radius Circles .............................. 3–5 Figure 3.7: Four Passes of a LEOSAR Satellite .................................................................... 3–6 Figure 3.8: Footprint of LEOSAR Satellite (Sarsat-10) ......................................................... 3–7 Figure 3.9: Global coverage of a LEOSAR satellite .............................................................. 3–8 Figure 3.10: A Doppler Curve for a Hypothetical FGB ......................................................... 3–9 Figure 3.11: Two Doppler Locations from a LEOSAR Satellite Pass ................................. 3–10 Figure 3.12: Confirmation by Two LEOSAR Passes .......................................................... 3–11 Figure 3.13: Footprint of GEOSAR Satellite (MSG-2) ....................................................... 3–12 Figure 4.1: A Schematic View of the MCC Network ............................................................ 4–1 Figure 4.2: Two Doppler Locations from a LEOSAR Satellite Pass for an EPIRB .............. 4–5 Figure 4.3: Confirmation of LEOSAR Data by a MEOSAR Detection ................................ 4–6 Figure 4.4: Example of an Unresolved Doppler Match ....................................................... 4–10 Figure 5.1: A Sample SIT 185 Message ................................................................................ 5–1 Figure 6.1: Sequence of Four SIT 185 Messages Sent to a SAR Service in Example 6-1 .... 6–1 Figure 6.2: Sequence of Three Beacon Messages Sent in Example 6.2 ................................ 6–7

Figure 6.3: Footprint of the GEOSAR INSAT-3A Satellite .................................................. 6–8 Figure 6.4: LEOSAR Initial Alert ........................................................................................ 6–10 Figure 6.5: Confirmation of Position Using a LEOSAR Alert ............................................ 6–12 Figure 6.6: The Two SIT 185 Messages in Example 6.4 .................................................... 6–14 Figure 6.7: ICAO 24-bit Addressing ................................................................................... 6–17 Figure 6.8: GEOSAR GNSS Position Alert ........................................................................ 6–18 Figure 6.9: LEOSAR Position Conflict Alert ...................................................................... 6–20 Figure 6.10 : Graphical Representation of the NOCR Alert Message ................................. 6–22 Figure 6.11: Unresolved Doppler Position Match ............................................................... 6–24 Figure 6.12: Ship Security Unlocated and Initial Alert ........................................................ 6–33 Figure 6.13: 406 MHz Interferer Alert ................................................................................. 6–37 Figure C.1: Western DDR Map ............................................................................................. C–1 Figure C.2: North West Pacific DDR Map ............................................................................ C–3 Figure C.3: South West Pacific DDR Map ............................................................................ C–4 Figure C.4: Central DDR Map ............................................................................................... C–5 Figure C.5: South Central DDR Map ..................................................................................... C–7 Figure C.6: Eastern DDR Map ............................................................................................... C–8 LIST OF TABLES Page Table 2.1: Maximum Precision of the FGB Location Protocols .......................................... 2–10 Table 2.2: Precision of the FGB Location Protocols with only Coarse Position ................. 2–11 Table 4.1: Determining if Two Locations for a Beacon are Independent .............................. 4–3 Table 5.1: Message Content for SIT 185 Messages ............................................................... 5–2 Table 5.2: GNSS Position Uncertainty ................................................................................ 5–13

1–1

INTRODUCTION 1.1 Overview The purpose of this document is to provide Rescue Coordination Centre (RCC) personnel and Search and Rescue Point of Contact (SPOC) personnel with an overview of the Cospas-Sarsat System and an understanding of the Cospas-Sarsat distress alert messages and their contents. This will allow RCCs and SPOCs to manage the response to search and rescue (SAR) incidents involving Cospas-Sarsat distress alerts in an informed manner. In the document, SAR Service will be used as a generic term to include both RCCs and SPOCs. The document also provides an overview of Cospas-Sarsat Ship Security Alert System (SSAS) alerts, which are similar to search and rescue distress alerts except that the notification of the alert is sent to a Competent Authority rather than a SAR Service. In the document, Responsible Agency will be used as a generic term to include SAR Services and Competent Authorities. 1.2 Document Organisation Section 1: provides a basic overview of the Cospas-Sarsat System. Section 2: provides information on Cospas-Sarsat distress beacons. Section 3: gives a brief overview of the satellite systems used by Cospas-Sarsat and the data produced using those satellite systems. Section 4: explains how a Mission Control Centre (MCC) processes beacon detection and location data and how the data is sent to Responsible Agencies. Section 5: provides detailed information on the types and contents of Cospas-Sarsat 406 MHz distress alert messages. Section 6: gives examples of 406 MHz distress alert messages sent to Responsible Agencies. Section 7: lists some questions that are frequently asked by personnel of Responsible Agencies and provides appropriate answers. 1.3 Cospas-Sarsat The International Cospas-Sarsat Programme is a satellite-based search and rescue distress alert detection system. The system was established in 1979 by Canada, France, the United States and the former Soviet Union. The name Cospas-Sarsat is formed from two acronyms. Cospas is an acronym for the Russian words "Cosmicheskaya Sistema Poiska Avariynich Sudov" which translates to "Space System

1–2

for the Search of Vessels in Distress". Sarsat is an acronym for Search and Rescue Satellite- Aided Tracking. The Mission Statement of the Programme states: “The International Cospas-Sarsat Programme provides accurate, timely and reliable distress alert and location data to help search and rescue authorities assist persons in distress.” The objective of the Cospas-Sarsat System is to reduce, as far as possible, delays in the provision of distress alerts to Responsible Agencies, and the time required to locate a distress and to provide assistance. These delays have a direct impact on the probability of survival of the person in distress at sea or on land. To achieve this objective, Cospas-Sarsat participant governments and agencies implement, maintain, co-ordinate and operate a satellite system capable of detecting distress alert transmissions from distress beacons that comply with Cospas-Sarsat specifications and performance standards, and of determining their position anywhere on the globe. The distress alert and location data are provided by Cospas-Sarsat Participants to the relevant Responsible Agencies. Cospas-Sarsat co-operates with the International Civil Aviation Organization (ICAO), the International Maritime Organization (IMO), the International Telecommunication Union (ITU) and other international organisations to ensure the compatibility of the Cospas-Sarsat distress alerting services with the needs, standards and applicable recommendations of the international community. Further information about the Programme can be found on the Cospas-Sarsat website (www.cospas-sarsat.int). A list of acronyms used in this document is provided in Annex A. 1.4 The Cospas-Sarsat System The Cospas-Sarsat system consists of: • distress beacons that send transmissions on 406 MHz, • satellites that process and/or relay the signals transmitted by distress beacons, • a Ground Segment that consists of: o ground receiving stations called Local User Terminals (LUTs) which process the satellite signals, o Mission Control Centres (MCCs) that provide the distress alert data to Responsible Agencies. Each Responsible Agency is supported by an MCC that sends beacon detection and location data (known as beacons alerts) to the Responsible Agency. As the name suggests, the Responsible Agency is responsible for managing the response to the beacon alerts,

1–3

o Return Link Service Provider (RLSP) that provides the service offered by some GNSS systems that sends a notification to the distress beacon after it has been detected by the Cospas-Sarsat System. (see section 2.6). Figure 1.1: An Overview of the Cospas-Sarsat Beacon Detection System The steps in Figure 1.1 are explained in the following sections. 1.4.1 Step 1: Distress Beacons There are four types of Cospas-Sarsat distress beacons: 1. Emergency Locator Transmitters (ELTs), including ELTs for distress tracking (ELT(DT)s), are designed for aviation use; 2. Emergency Position-Indicating Radio Beacons (EPIRBs) are designed for maritime use; 3. Personal Locator Beacons (PLBs) are intended for use by an individual person (i.e., not necessarily linked to an aircraft or a ship); and 4. Ship Security Alerting System (SSAS) beacons are designed for security situations for SOLAS vessels. Unlike the other types of beacons that have alert messages sent to a SAR Service, all SSAS alerts are sent to the Competent Authority for the country of registration of the SSAS beacon. Each type of distress beacon has different characteristics (such as duration of continuous operation (battery life) and beacon activation method) but all work in the same manner

• by transmitting an emergency message on 406 MHz. A unique hexadecimal identifier

1–4

(known as the Hex ID of the beacon) can be extracted from the emergency message. The Hex ID includes the country of registration for the beacon. A distress beacon may contain an internal receiver capable of determining a Global Navigation Satellite System (GNSS) location or may be capable of receiving data from an external device able to supply a GNSS location. The GNSS systems includes the American Global Positioning System (GPS), the European Galileo system, the Russian Glonass system and the BDS of China (P. R. of). The GNSS location may be transmitted as part of the emergency message and is also known as an encoded location. 1.4.2 Step 2: Search & Rescue Satellites The Cospas-Sarsat System uses three different satellite systems to detect distress beacons. The three satellite systems have different characteristics, but all provide beacon detection and location data: 1. The MEOSAR (Medium-altitude Earth Orbit Search and Rescue) satellites are the most recent addition to the Cospas-Sarsat System. MEOSAR satellites orbit the Earth at altitudes between 19,000 and 24,000 kilometres. 2. The LEOSAR (Low-altitude Earth Orbit Search and Rescue) satellites were the original satellites used in the Cospas-Sarsat system. LEOSAR satellites orbit the Earth in near-polar orbits at altitudes between 700 and 1,000 kilometres. 3. The GEOSAR (Geostationary Earth Orbit Search and Rescue) satellites appear stationary from the Earth. The GEOSAR satellites are in orbit approximately 36,000 kilometres from the Earth. 1.4.3 Step 3: Local User Terminals Each satellite system has its own type of LUT (Local User Terminal) that tracks the satellites and processes the signals received from the satellites. The MEOSAR system has ground stations called MEOLUTs; each MEOLUT tracks multiple MEOSAR satellites simultaneously. Using Difference of Arrival (DOA) techniques (described in section 3.1), a MEOLUT that receives data that has been relayed from a beacon through three or more satellites can compute a location estimate for that beacon. The LEOSAR system has LEOLUTs. Each LEOLUT has a single antenna that tracks a LEOSAR satellite when in view. The LEOLUT collects data from the satellite. A LEOLUT uses Doppler techniques (described in section 3.2) to generate location data. The GEOSAR system has GEOLUTs. Each GEOLUT receives data from one satellite (as the GEOSAR satellite is always in view) and collects and processes the data from that satellite. A GEOLUT is unable to generate a location for a beacon unless the beacon transmits a GNSS position. Each LUT forwards detection and location data to its associated Mission Control Centre.

1–5

1.4.4 Step 4: Mission Control Centres The Mission Control Centres (MCCs) form a network that distributes the beacon detection data around the world. Each MCC receives data from its LUTs and also data from the network of MCCs. The MCC processes data for each beacon incident, using the unique Hex ID of the beacon to identify all the detections associated with the same beacon incident. For each incident alert received the MCC determines the responsible MCC for the distribution of that alert. If it is itself the responsible MCC, it determines the Responsible Agency or Agencies to be informed of the beacon activation and sends the data to the Responsible Agency directly. Otherwise, the MCC sends the data through the MCC network to the responsible MCC that can deliver it to the relevant Responsible Agency. 1.4.5 Step 5: Responsible Agencies A Responsible Agency is either an RCC or SPOC (for ELT, EPIRB and PLB activations), or a Competent Authority (for SSAS activations). The Responsible Agency receives beacon alerts from its associated MCC. Each beacon alert contains beacon detection data for the related beacon incident and may also have location data. The messages sent between an MCC, and its national Responsible Agencies are a matter of national sovereignty and are not explicitly defined by Cospas-Sarsat. The message formats described in this document are specified by Cospas-Sarsat for communications between an MCC and a foreign Responsible Agency. However, most MCCs use the same format (or something very similar to it) to communicate with their national Responsible Agencies. The information that is distributed by an MCC is structured in a format known as Subject Indicator Type (SIT) format. In particular, the information that is sent from an MCC to a Responsible Agency is usually a plain text message in a format known as a SIT 185 format. An example of a SIT 185 message is shown in Figure 1.2. The fields of the SIT 185 message are explained in detail in sections 5 and 6. ELT(DT) data is only transmitted to the Location of Aircraft in Distress Repository (LADR) by the nodal MCC associated with the destination MCC (or by another nodal MCC on its behalf), in a special message format. This message format is not explained further in this Handbook.

1–6

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 12590 AUMCC REF C00F429578002C1
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER – PLB SERIAL NO 0042334 HEX ID C00F429578002C1 COUNTRY OF BEACON REGISTRATION 512/NEWZEALAND BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 08 JAN 17 0354 UTC BY SARSAT 10 GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A - 41 14 S 172 31 E PROB 79 PERCENT DOPPLER B - 48 20 S 135 51 E PROB 21 PERCENT
5. OTHER INFORMATION DETECTION FREQUENCY 406.0280 MHZ
6. REMARKS NIL END OF MESSAGE Figure 1.2: A Sample SIT 185 Message 1.5 Reference Documents The Cospas-Sarsat documents listed below are available free-of-charge from the Cospas- Sarsat web site at www.cospas-sarsat.int: • C/S A.001 – Cospas-Sarsat Data Distribution Plan (DDP) This document provides requirements for the exchange of alert and System data between MCCs and Responsible Agencies. • C/S A.002 – Cospas-Sarsat Mission Control Centre Standard Interface Description (SID) This document provides information on message content and formats for the automatic exchange of data between MCCs and to Responsible Agencies. It also describes the message content and format used by MCCs to send data for ELT(DT)s to the LADR. • C/S A.005 – Cospas-Sarsat Mission Control Centre Performance Specification and Design Guidelines This document provides the specific performance requirements for a Cospas-Sarsat Mission Control Centre (MCC).

1–7

• C/S G.003 – Introduction to the Cospas-Sarsat System. This document provides detailed information of the System history, Programme Management, concept of operation and a description of the various components. It is the ideal document to read to obtain a general understanding of the Cospas-Sarsat System. • C/S G.005 – Cospas-Sarsat Guidelines on 406 MHz Beacon Coding, Registration and Type Approval. This document was developed as an aide to help in understanding the beacon coding and the processes of registration and type approval. It also complements and assists in the understanding of some of the more complex details in the beacon technical specification document, C/S T.001. • C/S G.010 – MCC Handbook. This document describes responsibilities and functions of an MCC and MCC operators. • C/S P.011 – Cospas-Sarsat Programme Management Policy. This high-level document provides information on all aspects of the System and its management. In the main, it is intended for senior Managers. • C/S S.007 – Handbook of Beacon Regulations This document provides a summary of regulations issued by Cospas-Sarsat Participants and other countries regarding the carriage of 406 MHz beacons, and includes information on the coding and registration of 406 MHz beacons in each country. • C/S T.001 – Specifications for Cospas-Sarsat 406 MHz Distress Beacons This document defines the specifications for the development and manufacture of 406 MHz distress First-Generation Beacons (FGBs) and the beacon message content. • C/S T.018 – Specifications for Second-Generation Cospas-Sarsat 406 MHz Distress Beacons This document defines the specifications for the development and manufacture of 406 MHz distress Second-Generation Beacons (SGBs) and the beacon message content. Other materials, such as sets of videos, graphics, images, history book, Information Bulletin and published articles are available free-of-charge from the Cospas-Sarsat website at www.cospas-sarsat.int under the Media Gallery tab. Documents listed below are available from the International Maritime Organization (www.imo.org) or the International Civil Aviation Organization (www.icao.int) for a fee: • Doc 9731 – AN/958 – IAMSAR Manual (International Aeronautical and Maritime Search and Rescue Manual), • Doc 8585 – “Designators for Aircraft Operating Agencies, Aeronautical Authorities and Services”, • Doc 10054 – “Manual on Location of Aircraft in Distress and Flight Recorder Data Recovery”,

1–8

• [Doc 10165 – “Manual on Global Aeronautical Distress and Safety System (GADSS)”].

• END OF SECTION 1 -

2–1

COSPAS-SARSAT BEACONS 2.1 Beacon Types The Cospas-Sarsat System provides alerting services for the following four types of beacons: 1. Emergency Locator Transmitters (ELTs), including ELT(DT)s, are designed for aviation use; 2. Emergency Position-Indicating Radio Beacons (EPIRBs) are designed for maritime use; 3. Personal Locator Beacons (PLBs) are intended for use by an individual person (i.e., not necessarily linked to an aircraft or a ship); and 4. Ship Security Alerting System (SSAS) beacons are designed for security situations for SOLAS vessels. Figure 2.1: Distress Beacon Types

2–2

2.1.1 ELTs ELTs are designed for use in aircraft. Most ELTs are installed in aircraft so that they activate on impact. An automatic activation is triggered by strong acceleration or deceleration on a “G” sensor device. These ELTs can also be activated manually by the crew in the cockpit. A distress tracking ELT, or ELT(DT), may be activated by the aircraft avionics system when it detects an unusual in-flight situation, as defined by ICAO in Global Aeronautical Distress and Safety System (GADSS) documents, that indicates that the aircraft is in imminent danger of crashing. These ELTs can also be activated manually by the crew in the cockpit. An ELT(DT) can only be deactivated by the same means used for activation (i.e., by avionics or manually). Other ELT models than ELT(DT) that are carried on an aircraft may have to be activated manually. Except for ELT(DT)s, all ELTs are required to have a minimum duration of continuous operation (battery life) of 24 hours. ELT(DT)s are required to have a minimum duration of continuous operation (battery life) of 370 minutes and may be powered by the aircraft. 2.1.2 EPIRBs EPIRBs are designed for maritime use and float in water. An EPIRB is required to have positive buoyancy in water to ensure that the antenna is vertically upright, providing the best antenna performance for beacon transmission. There are two activation mechanisms for EPIRBs. EPIRBs can have an automatic activation switch that incorporates a water sensor. When the sensor comes in contact with water for a few seconds, the EPIRB will self-activate. EPIRBs with an automatic activation switch can also be manually activated. Other EPIRB models can only be manually activated. A float-free EPIRB is housed in an enclosure that deploys (using a pressure-sensitive hydrostatic release unit) the EPIRB when the enclosure is submerged. The float-free EPIRB has an automatic activation switch that activates when it comes in contact with water. A non-float-free EPIRB is either loose in the vessel or mounted on a manual release bracket. Note that an EPIRB with an automatic activation switch is disabled while mounted in a manual release bracket and will not activate, even if it comes in contact with water while in the bracket. All type-approved EPIRBs are required to have a minimum duration of continuous operation (battery life) of 24 hours; however, GMDSS requires a minimum duration of continuous operation (battery life) of 48 hours.

2–3

2.1.3 PLBs PLBs are designed to be worn or carried by individuals rather than attached to an aircraft or vessel. PLBs are smaller and lighter than ELTs and EPIRBs. In some countries, PLBs are permitted for use in aviation and maritime situations but are not necessarily designed for those environments. For example, PLBs are not required to float in water, and even if a PLB does float in water, it may not keep its antenna upright affecting the performance of the PLB. PLBs are manually activated only and are required to have a minimum battery life of 24 hours. 2.1.4 SSAS Beacons Cospas-Sarsat provides alerting services for the Ship Security Alert System (SSAS). An SSAS beacon is activated in case of attempted piracy or terrorism and appropriate law enforcement or military forces can then be dispatched. SSAS beacons are carried under the IMO’s Safety of Life at Sea (SOLAS) Convention and are usually fitted in the bridge of a ship. SSAS beacon transmissions are processed in the same manner as distress alerts by the Cospas-Sarsat System except that all messages relating to SSAS beacons are sent to the Competent Authority (per SOLAS Convention, Chapter XI-2, Regulation 6.2.1). Messages relating to SSAS beacons are not sent to a SAR Service unless the SAR Service is also the Competent Authority for the country of registration encoded in the beacon. SSAS beacons can only be activated manually. The SSAS contact details for ship security competent authorities are made available by IMO Member States in the IMO Global Integrated Shipping Information System (GISIS) database at https://gisis.imo.org/Public/Default.aspx. The Maritime Security button, after appropriate login, provides access to “Proper recipients of SSAS alerts”. States that allow use of SSAS beacons have also identified their ship security competent authority to their associated MCC.

2–4

Figure 2.2: The GISIS Maritime Security Website Interface Figure 2.3: A Ship Security Alert System (SSAS) Beacon 2.1.5 ELT(DT) Cospas-Sarsat has developed specifications for distress tracking of aircraft in-flight. These Emergency Locator Transmitter for Distress Tracking beacons (ELT(DT)s) are compliant with ICAO GADSS requirements for Autonomous Distress Tracking (ADT)

2–5

to transmit accurate position information at least every minute, which should allow an aircraft crash site to be located within six nautical miles (6 NM). These requirements are described in the ICAO document 10054, the Manual on Location of Aircraft in Distress and Flight Recorder Data Recovery. An ADT capability will be required in most new commercial aircraft from the beginning of 2025. Although an ELT(DT) will share many characteristics with existing ELTs, an ELT(DT) may have some key differences: • activation by an automatic triggering event including unusual attitude, altitude or speed or total loss of propulsion or thrust, • a more rapid transmission schedule, • every ELT(DT) will have a GNSS receiver and will be able to provide an accurate GNSS position with each burst, • an ELT(DT) may be capable of being activated remotely by request from a responsible agency. The remote activation would use the Return Link Service (RLS) mechanism currently in development, • a cancellation message which will indicate the activation event is no longer active (for example, the events generating the automatic triggering have returned to normal values). LUTs and MCCs have different processing rules for an ELT(DT); for example, locations are not merged as the ELT(DT) is assumed to be on a fast-moving aircraft. 2.2 Characteristics of a 406-MHz Beacon Cospas-Sarsat type-approved 406-MHz-beacon models are compatible with Cospas-Sarsat satellites and comply with requirements of the 406-MHz First-Generation Beacon (FGB) specification standard described in Cospas-Sarsat document C/S T.001 or the requirements of 406 MHz Second Generation Beacon (SGB) specification standard described in Cospas-Sarsat document C/S T.018. Beacons are verified by thorough testing at Cospas-Sarsat accepted test facilities for characteristics including compatibility of RF-characteristics and signal waveform, digital message structure, beacon performance at different temperature conditions, and minimum duration of continuous operation. The list of type-approved 406 MHz beacon models is maintained by the Cospas-Sarsat Secretariat and may be seen on the Cospas-Sarsat website. Except for ELT(DT)s, most FGB types transmit a 5-Watt radio frequency burst of approximately 0.5-second duration every 50 seconds, where the first burst occurs approximately 50 seconds after activation of the beacon. Exceptions include ELT (AF)s activated by G-switch or deformation sensor (for which the first-burst delay is no more than 15 seconds) and SSAS beacons. SGBs transmit on a varying schedule where the transmission occurs less frequently as the duration of the transmission continues, as a means to conserve the beacon’s battery capacity.

2–6

For FGB and SGB ELT(DT)s, bursts are transmitted every 5 seconds in the first 120 seconds after activation, and less frequently afterwards. ELT(DT)s start transmitting no more than 5 seconds after activation. All ELT(DT)s have a cancellation function, whereby activation of an ELT(DT) can be cancelled by the same means by which it was initiated. FGBs transmit distress signals on a specified frequency channel within the 406 MHz frequency band (i.e., between 406.0 and 406.1 MHz) based on the beacon model (e.g., 406.025 MHz or 406.040 MHz). SGBs transmit distress signals across the allocated 406 MHz frequency band (using “spread-spectrum” modulation) which provides protection against interference occurring in specific portions of the 406 MHz frequency band. All SGBs have a cancellation function. The burst transmitted includes a digital message that contains information that can be used to determine the Hex ID of the beacon. 2.3 The Beacon Message The transmission from a distress beacon contains a digital message, as further described in sections 2.3.1 and 2.3.2 below. More detailed information on beacon coding can be obtained from Cospas-Sarsat document C/S T.001, “Specification for [FGB] Cospas-Sarsat 406 MHz Distress Beacons”, Cospas- Sarsat document C/S T.018, “Specification for Second-Generation Cospas-Sarsat 406 MHz Distress Beacons” and document C/S G.005, “Cospas-Sarsat Guidelines on 406-MHz Beacon Coding, Registration and Type Approval”. Each document is available from the Cospas-Sarsat website at www.cospas-sarsat.int. 2.3.1 The First Generation Beacon Message The FGB “message” transmitted by the beacon is either a short message of 112 bits or a long message of 144 bits. Every FGB “message” begins with 24 bits of synchronisation data. These bits allow the start of a valid FGB message to be identified. The remaining bits in the FGB message contain data that is organised depending on the beacon coding protocol used for the beacon. Every FGB “message” has a unique 15 Hex ID that includes the country of beacon registration. Cospas-Sarsat has developed two major categories of FGB message protocols, User protocols, and Location protocols: • User protocols are short FGB messages that consist of 112 bits of data that include the beacon identification and other important SAR information, but do not allow for encoded GNSS position data, • Location protocols are long FGB messages that consist of 144 bits of data that include encoded GNSS position data (if available) as well as beacon identification data. Both the User and Location protocols have various subtypes that provide a coding suited to the individual beacon. For example, the EPIRB-MMSI Location Protocol contains a field to

2–7

store the last six (6) digits of the MMSI (the country code provides the first three (3) digits for the MMSI). A beacon with an EPIRB-MMSI protocol must be programmed with the known MMSI of the vessel that carries the EPIRB. In contrast, the Serial Location Protocols contain a field to store a 24-bit serial identification number. A beacon with a Serial Protocol can be programmed by the manufacturer using serial numbers provided by the national beacon authority. A portion of the FGB ELT(DT) beacon message includes a rotating field, where some transmissions include the three-letter designator (3LD) of the aircraft operator, and other transmissions include a more precise GNSS location. 2.3.2 The Second Generation Beacon Message The SGB message consists of 250 bits, of which 48 bits are within a rotating field type. The use of a rotating field expands the amount of information that can be provided in the beacon message by including certain kinds of information in one rotating field type and other kinds of information in another rotating field type. Every SGB has a fixed identification consisting of Type Approval Certificate (TAC) number and serial number that is independent of the encoding of vessel or aircraft identification information in the beacon message. Every SGB message has a unique 23 Hex ID that includes the country of beacon registration. Compared to the FGB message, the additional bits in the SGB message enable additional information to be provided, including a more precise GNSS position and the time that the GNSS position was updated. 2.4 Hexadecimal Identity of a 406-MHz Beacon Every beacon has a Unique Identification Number (UIN, also known as the beacon Hex ID). The Hex ID for an FGB consists of 15 hexadecimal characters. For example, 3EF42AF43F81FE0 is the Hex ID of an Australian EPIRB. The Hex ID is displayed on the beacon (see Figure 2.4). While a SGB has a 15 Hex ID that is backwards compatible with the 15 Hex IDs assigned to FGBs, the complete Hex ID for a SGB consists of 23 hexadecimal characters. Some information from the FGB or SGB message sent to RCCs and SPOCs within the SIT 185 text message is not available in the 15 Hex ID and 23 Hex ID.

2–8

Figure 2.4: Beacon with Hex ID 3EF42AF43F81FE0 The Hex ID is used operationally as the identification in Cospas-Sarsat distress alert messages sent to Responsible Agencies. The Hex ID can be decoded to provide a variety of information about the beacon, depending on the protocol used to encode it. Beacon coding protocols are described in documents C/S T.001 and C/S T.018 (available on the Cospas-Sarsat website). All Hex IDs include a country of registration provided as a MID (Maritime Identification Digit) code, a three-digit identity. A list of all MID codes used by Cospas-Sarsat is provided in Annex B of this document. Hex IDs can be decoded using a software tool, also available on the Cospas-Sarsat website. Figure 2.5 shows the result of decoding the Hex ID of the beacon from Figure 2.4 using the decode tool on the Cospas-Sarsat website.

2–9

Figure 2.5: Decode of Beacon 3EF42AF43F81FE0 2.5 Direction Finding on 406-MHz Beacons Most 406 MHz FGBs and some SGBs transmit a quasi-continuous secondary signal on 121.5 MHz to enable suitably equipped SAR forces to home on the distress beacon using radio direction finding techniques (see ICAO-IMO document 9731 known as the “IAMSAR Manual”). Homing on the 406-MHz burst is also being undertaken by some SAR authorities. Direction finding on 406 MHz allows specially equipped SAR aircraft to accurately track the course to the 406-MHz beacon, even if the signal is not continuously transmitted (see section 5.5.1 for 406 MHz beacon channels). 2.6 Return Link Service (RLS) The Return Link Service (RLS) provides notification to a 406 MHz beacon that an alert transmitted by the beacon has been detected by a LUT and distributed via the Cospas-Sarsat MCC network to the MCC whose service area covers the beacon confirmed position (see section 4.1.3 for a description of the MCC reference position). This service is intended to provide acknowledgement of the reception of the alert message to persons in distress and is only available for 406 MHz beacons coded to provide a return link. Once notified that an RLS-capable beacon has been located, the RLSP interfaces to the Ground Segment for transmitting return link messages to appropriate satellites, which, in turn, transmit return link messages (RLMs) to the transmitting beacon. After receipt of the return link message by the beacon, subsequent beacon transmissions include the return link message receipt status, and a notification that includes the receipt status is distributed via the Cospas- Sarsat MCC network to the designated RLSP. Once notified that the beacon has received the return link message, the RLSP interfaces to the relevant ground segment which will cease transmitting return link messages to satellites. Illustration of RLS is provided at Figure 1.1. Further information on the Return Link Service is provided in document C/S R.012.

2–10

2.7 GNSS Positions A distress beacon with GNSS capability is able to transmit a GNSS position as part of its beacon message. There are two mechanisms used to derive the GNSS position: either the distress beacon has an internal GNSS receiver, or the distress beacon receives the GNSS data from an external device that connects to the beacon. If the distress beacon with GNSS capability does not provide a GNSS position (for example, as the internal receiver cannot derive a GNSS position as it cannot track sufficient GNSS satellites), default values are transmitted in the beacon message that indicate that there is no encoded GNSS position available. Distress beacons that transmit GNSS position data are coded with a Location protocol; however, for FGBs, the particular Location protocol used affects the precision of the GNSS position data that can be sent in a beacon message. Table 2.1 lists the precision for the FGB Location protocols. Table 2.1: Maximum Precision of the FGB Location Protocols Protocol Maximum Difference Equivalent Distance at Equator User Location 2 minutes 3.7 kilometres Standard Location 2 seconds 60 metres National Location 2 seconds 60 metres RLS 2 seconds 60 metres ELT(DT) 2 seconds 60 metres In some situations, a beacon message may have errors that result in the LUT not being able to produce a fine GNSS position. Instead, a coarse GNSS position is produced. Table 2.2 shows the coarse precision for the Location protocols that may have a coarse precision GNSS position. Additional information: According to document C/S T.001 section “Internal Navigation Device Performance”, for FGBs coded with the Standard, National, or RLS Location protocols, the GNSS receiver accuracy must be below 500m. For suspected moving beacons, RCC operators should take into account that the beacon may have drifted between the time the GNSS position has first been encoded in the beacon message and the time a new GNSS position information is sent to the RCC or SPOC within a SIT 185 message including this GNSS position. Specifically, for FGBs other than ELT(DT)s in in-flight mode: 1. a maximum 52.5-second period (up to 120-second period for ELT(DT) in post-crash mode) may occur between the time the GNSS receiver processes the GNSS position and the time this position is encoded in the beacon burst and sent to the satellite, 2. the refresh rate of the internal GNSS receivers is defined such as:

2–11

a) new beacons type-approved after 2022 should update their GNSS location between 4 minutes 25 seconds and 15 minutes (i.e., the GNSS position provided in a new SIT 185 message can be up to 15-minute old), b) new beacons type-approved between 2014 and 2022 should update their GNSS location at least once every 30 minutes (i.e., the GNSS position provided in a new SIT 185 message can be up to 30-minute old), c) it is not specified for beacons type-approved before 2014 (i.e., the GNSS position provided in a new SIT 185 message can be more than 30-minute old). Consequently, RCCs and SPOCs may receive SIT 185 messages updating the beacon position information for which only the independent position (i.e., the DOA or the Doppler position) has been updated, and therefore, still containing GNSS position information that has been refreshed several minutes prior to the timestamp indicated in the SIT 185 message. For most beacons, the refresh rate of their internal GNSS receiver is available on the Cospas-Sarsat website at https://www.cospas-sarsat.int/en/beacons-pro/experts-beacon- information/approved-beacon-models-tacs?view=tac_beacons, selecting the TAC number and searching for the field “Encoded Position Data Update Interval [Fix]”. (See also sections 5.3.8 “Source of GNSS Position Data” and 5.4.7 “Summary Guidance for the Use of Position Data”.) Table 2.2: Precision of the FGB Location Protocols with only Coarse Position Protocol Maximum Difference* Equivalent Distance at Equator Standard Location 7 minutes 30 seconds 13.9 kilometres National Location 1 minute 1.9 kilometres RLS 15 minutes 27.8 kilometres ELT(DT) 15 minutes 27.8 kilometres

• Assumes all available bits are used to provide the coarse position; see section 5.8.1. Note: For SGBs, the precision of the GNSS position provided to Distress authorities is approximately 10 metres. Note: All ELT(DT)s are required to have a GNSS capability, and the GNSS location is normally considered the primary location data for an ELT(DT). A DOA location is only provided for an ELT(DT) if the MEOLUT is commissioned to provide DOA location for fast-moving beacons. LEOLUT Doppler location is not provided to SAR services for ELT(DT)s. 2.8 Beacon Registration As each beacon has a unique Hex ID, it is possible for each country to maintain a beacon database to store supplementary information about a beacon, such as contact details for its owner, other emergency contacts and details of any associated vessel or aircraft.

2–12

A country can either provide its own beacon database or use the Cospas-Sarsat International Beacon Registration Database (IBRD). Details of beacon databases can be found under the “406-MHz-Beacon Registers” section of the Contact Lists on the Cospas-Sarsat web site. 2.9 International Beacon Registration Database (IBRD) Despite the clear advantage of registration, a significant number of beacons are not properly registered due to a lack of registration facilities in a number of countries. Furthermore, a number of beacon registers do not have 24-hour points of contact easily accessible by Responsible Agencies. Therefore, Cospas-Sarsat provides the International Beacon Registration Database (IBRD). 2.9.1 International Regulations and Purpose of the IBRD IMO policy, as stated in IMO Assembly Resolution A.887(21), adopted on 25 November 1999, provides in paragraph 2 that “every State requiring or allowing the use of these GMDSS systems should make suitable arrangements for ensuring registrations of these identities are made, maintained and enforced.” These arrangements are further clarified in paragraph 12 which provides that “Every State should maintain a suitable national database or co-ordinate with other States of their geographical area to maintain a joint database”. ICAO policy on registration of ELTs is contained in Chapter 5 of the ICAO Convention, which provides that “States shall make arrangements for a 406 MHz ELT register. Register information regarding the ELT shall be immediately available to search and rescue authorities. States shall ensure that the register is updated whenever necessary.” It is, therefore, the sole responsibility of States to provide the appropriate regulatory environment, facilities and resources that are required for an effective registration process. The IBRD is a means designed by Cospas-Sarsat to assist with the registration process when, due to a lack of resources, States have not implemented facilities for a national register. States may choose to selectively allow registration of beacons in the IBRD by beacon type. The IBRD is also meant to assist States in making their registration data available to SAR authorities on a 24-hour basis, seven days per week. However, it is not designed to become the unique central repository for all beacon registration data. In providing the IBRD and making the IBRD available to States and users under their jurisdiction, Cospas-Sarsat does not accept or take over the specific responsibilities of States as stated by IMO and ICAO and declines all responsibilities or liabilities that might be associated with the registration of any data in the IBRD, or its availability or unavailability to SAR authorities. When States choose to allow the registration of data from users under their jurisdiction in the IBRD, or upload national registration data into the IBRD, they retain full and exclusive responsibility for the integrity of such data, its accuracy and its availability to SAR. In this regard, Cospas-Sarsat does not provide any guaranty as to the continuous operation of the IBRD.

2–13

2.9.2 Using the IBRD The IBRD is designed to be freely available to users with no access to national registration facilities and to Administrations who wish to avail themselves of the facility to make their national beacon registration data more available to SAR services. However, direct registration of beacons in the IBRD is not allowed for the country codes of Administrations that have informed Cospas-Sarsat of their decision to control the registration of beacons under their jurisdiction, whether in the IBRD or in their own national registration databases. The IBRD provides various levels of access to: a) beacon owners who wish to register their beacons when no registration facility exists in their country and the responsible Administration has agreed to allow direct registration in the IBRD; b) Administrations who control the registration of beacons identified with their country code, but wish to make registration data available to international Responsible Agencies via the IBRD; c) Responsible Agencies that need to access beacon registration data to efficiently process distress alerts; and d) other authorised government entities or agencies for the purpose of controlling the proper coding or registration of beacons. The functional requirements for the IBRD are provided in the document C/S D.001 “Functional Requirements for the Cospas-Sarsat International Beacon Registration Database” and the IBRD operations policy is defined in the document C/S D.004, “Operations Plan for the Cospas-Sarsat International Beacon Registration Database”. Access to the IBRD (www.406registration.com) is controlled by user codes assigned by the Cospas-Sarsat Secretariat (www.cospas-sarsat.int) in accordance with Council guidelines. Administrations wishing to use the IBRD should designate a National Point of Contact. Cospas-Sarsat will accept designations from the Cospas-Sarsat Representative or, for non-participating countries, the IMO or the ICAO Representative for that country. The Secretariat will provide each National IBRD Point of Contact with user identifications and passwords to be used by: • National Data Providers for registration of beacons with their country code(s), • Responsible Agencies for IBRD queries, • authorised shore-based service facilities and inspectors to verify proper coding and actual registration of the beacon. These IBRD user identifications and passwords should be distributed within each country under the responsibility of the National IBRD Point of Contact.

2–14

In case of forgotten password, Responsible Agencies are invited to urgently contact their National IBRD Point of Contact to retrieve their account details. If this is not possible, contact the Cospas-Sarsat Secretariat (www.cospas-sarsat.int), noting the Cospas-Sarsat Secretariat, situated in Montreal, Quebec, Canada, is defined as an administrative body which is consequently not reachable 24 hours a day, seven days a week. Detailed rules for accessing the IBRD are provided in the document C/S D.004. Annex D contains a guide to assist a Responsible Agency using the IBRD. 2.10 Beacon Regulation International regulations applicable to 406 MHz beacons are contained in document C/S S.007; they include performance standards for 406 MHz beacons and guidelines to avoid false alerts, information on beacon maintenance and testing, as well as guidance on beacon protocols permitted by the country of registration. 2.11 Beacon Testing 406 MHz beacons are designed with a self-test capability for evaluating key performance characteristics. Initiating the beacon self-test function will not generate a distress alert in the Cospas-Sarsat System. However, it will use some of the beacon's limited battery power and should only be used in accordance with the beacon manufacturer's guidance. On occasions, a Responsible Agency may wish to activate an operational 406 MHz beacon; for example, for SAR training purposes. As the beacon activation may be detected and treated as a live incident by the Cospas-Sarsat System, all activations for non-distress purposes must be approved in advance. Requests to conduct a live beacon activation should be directed to the MCC that services the location in which the activation is planned and, if the location is not within the country of registration, the MCC responsible for the country in which the beacon is registered. When making a request the following information should be provided: • Objective of the activation, • Description of the event, • Location, • Date, time and duration, • Beacon Hex ID (15 hexadecimal characters for an FGB or an SGB, or 23 hexadecimal characters for an SGB), • Point of contact. The responsible MCC will advise other MCCs of the planned beacon activation. If the homing signal on the beacon will be active, relevant aviation authorities must also be advised of the planned beacon activation.

2–15

2.12 Inadvertent Alert Cospas-Sarsat provides guidance on its website in case of inadvertent alerts occur, as follows: “If a beacon is inadvertently activated, the beacon immediately should be turned off if possible. If the beacon does not have an “off” function, it should be shielded from the sky by placing it in a metal container (a solid metal box or a refrigerator, for example). Because an alert likely will be received by the satellites even if the beacon was on for only a short time, you should immediately contact the agency in your region responsible for managing Cospas-Sarsat distress alerts to prevent unnecessary assignment of search and rescue resources that may be needed for a real emergency somewhere else. If your region has a Cospas-Sarsat Mission Control Centre in the "Contact Lists" (select “MCC – Mission Control Centre” from the drop-down choices), please notify the centre in your area. Otherwise select “SPOC – SAR Point of Contact” from the "Contact Lists" and notify them of your inadvertent alert. The "Contact Lists" are available under our Professional website. There is no penalty for inadvertent activation of a beacon if there was no malicious intent.” When reported to an MCC, the source of the alert should be categorized as depicted in the graphic below. Figure 2.6: Information Graphic on Sources of False Alerts

• END OF SECTION 2 -

3–1

COSPAS-SARSAT SATELLITE SYSTEMS Cospas-Sarsat uses three satellite systems, MEOSAR, LEOSAR and GEOSAR. Further information on each satellite system can be found on the Cospas-Sarsat web site (www.cospas- sarsat.int). All the satellite systems have equipment known as a SAR payload placed on satellites that have been designed for and are primarily used for other purposes. The two general categories of equipment are: 1. SAR Repeater (SARR): A SAR repeater receives a beacon transmission on 406 MHz and retransmits the transmission on a different frequency, 1544 MHz. A SAR repeater is sometimes called a bent pipe as it simply redirects the signal from the beacon back to the earth for reception by a LUT. SARR instruments are carried on all Cospas-Sarsat satellites. The satellite must have mutual visibility to the beacon and the LUT for detection to occur. 2. SAR Processor (SARP): A SAR processor receives a beacon transmission on 406 MHz and stores the time of arrival, the received frequency and the beacon message in a buffer. The data in the buffer is re-transmitted until overwritten by a more recent detection. The retransmitted signal uses the 1544 MHz frequency. SARP instruments are carried only on the LEOSAR satellites. The three satellite systems are described in more detail in the following sections with a description of the beacon detection and location data that can be determined by a LUT associated with the satellite system. Every satellite has a footprint on the Earth’s surface. The footprint is the area that the satellite can see at sea level on the Earth’s surface. A satellite can only detect signals from beacons that are within its footprint. The footprints shown in the following sections (for example, Figure 3.2) show the maximum footprint with a zero-degree elevation. 3.1 MEOSAR The MEOSAR space segment consists of SAR repeaters placed on the satellites of the Global Navigation Satellite Systems (GNSS): • GPS satellites operated by the United States, • Russian Federation Glonass navigation satellites, • European Galileo navigation satellites • Chinese BDS navigation satellites. These MEOSAR satellites orbit the Earth at altitudes between 19,000 and 24,000 kilometres, a range considered as a medium-altitude Earth orbit. The radius of a MEOSAR satellite footprint is about 6,000 to 7,000 kilometres. MEOSAR is designed to provide continuous global coverage of the Earth.

3–2

Figure 3.1: A Schematic View of the Galileo Constellation (which is one of the constellations of the MEOSAR System) The footprint of a GPS MEOSAR satellite is shown in Figure 3.2. Figure 3.2: Footprint of a GPS MEOSAR Satellite A MEOLUT tracks multiple MEOSAR satellites in view at the same time. Typically, a MEOLUT has a number of antennas, and each antenna tracks a separate MEOSAR satellite. r = 7,000 km z = 24,000 km

3–3

Upon receiving a transmission (a beacon burst) from a 406 MHz distress beacon via a MEOSAR satellite, a MEOLUT will generally measure two key values: the Time of Arrival (TOA) and the Frequency of Arrival (FOA). Assuming reception of beacon transmissions through at least three distinct MEOSAR satellites, MEOLUT processing can provide a two- dimensional (longitude and latitude) beacon location using a combination of time difference of arrival (TDOA) and frequency difference of arrival (FDOA) computations. The location computed by a MEOLUT is known as a difference of arrival (DOA) location. Three- dimensional locations (i.e., with the addition of a computed altitude) are possible when the beacon burst is relayed to a MEOLUT via four or more MEOSAR satellites. Figure 3.3: An Overview of the MEOSAR System In Figure 3.3 above, distress beacons (EPIRB, PLB or ELT) transmit a 406 MHz signal that is detected by MEOSAR satellites in the BDS, GPS, Glonass and Galileo constellations. The beacon transmission is relayed on 1544 MHz and detected by a MEOLUT. Beacon and location data is sent from the MEOLUT to an MCC and then to a Responsible Agency to initiate a response. The diagram also shows the Return Link Service offered by MEOSAR. A message can be sent to particular MEOSAR satellites that are capable of sending a return link message to a beacon with return link functionality. In addition to calculating beacon locations using a single burst relayed by different satellites, subsequent bursts can then be used to refine the beacon location. A location generated using more than a single burst is known as a multi-burst location. A MEOLUT may produce any of four possible forms of data: 1. A beacon detection without location: A beacon is detected but there is no location data associated with the detection. 2. A beacon detection with a GNSS position: A beacon is detected and there is a GNSS position encoded in the beacon message.

3–4

A DOA (Difference of Arrival) location: A beacon is detected, and using DOA techniques, the MEOLUT is able to generate an independent estimate of the location of the beacon. Typically, three or more satellites must detect the beacon to generate a DOA location. A DOA location may be generated from a single burst from a beacon. 4. A DOA location and a GNSS position: A beacon is detected; the beacon message contains a GNSS position and a DOA position is also generated. All ELT(DT)s are required to be capable of transmitting a GNSS location in the beacon message. A DOA location is only provided to Distress Authorities for an ELT(DT) if the MEOLUT is commissioned to provide DOA locations for fast-moving beacons. Expected Accuracy for DOA Location For each DOA location, an Expected Accuracy (i.e., estimated error) value is computed. Information on the Expected Accuracy, also known as the Expected Horizontal Error (EHE), is provided in the SIT 185 message as described in Paragraph 4. This value is the radius of the circle centered on the DOA location that should contain the true beacon location with a 95% probability. In other words, there is a 95% probability that the location error, which is defined as the distance between the DOA location and the actual beacon location, is lower than the Expected-Accuracy value. The Figure below illustrates the configuration for which the DOA location error is lower than the associated Expected-Accuracy value, with the corresponding confidence percentage. Figure 3.4: DOA Location Error Smaller than the Associated Expected-Accuracy Value Additional details on the Expected Accuracy for DOA Location: The Expected-Accuracy specification is further refined to ensure that Expected-Accuracy values associated with a DOA location provide a confident reflection of the location error, and in particular that the Expected Accuracy does not overestimate the location error in any significant way. This situation should happen for 95% of the MEOSAR DOA locations MEOSAR DOA location Actual beacon location Expected Accuracy Location error

3–5

In addition to the 95% confidence, Expected-Accuracy values must meet the following requirement (per section 5.10 of document C/S T.019 – EHE). Namely, to ensure that the associated Expected-Accuracy value does not underestimate the MEOSAR location error, the DOA location error must be smaller than two times the associated Expected-Accuracy value at minimum 99% of the time. In other words, there is only a maximum 1% probability that the DOA location error is greater than two times the Expected-Accuracy value. The Figure below illustrates this additional Expected-Accuracy-related boundary: Figure 3.5: Additional Expected-Accuracy-Related Boundary Figure 3.6: Probability of the Actual Beacon Location Being Within the Expected Accuracy-Radius and Two-Times Expected Accuracy-Radius Circles 95% probability that the location error be below the Expected-Accuracy value Expected Accuracy

99% probability that the location error be below 2 x Expected Accuracy <1% probability that the location error be above 2 x Expected Accuracy 2 x Expected Accuracy Contains the actual location with a 95% probability Contains the actual location with a >99% probability

3–6

3.2 LEOSAR The LEOSAR satellites are low-altitude (between 700 and 1000 kilometres above the Earth) spacecraft in near-polar orbits. As the LEOSAR satellite’s revolution takes about 105 minutes, two successive paths of the same satellite are separated, due to the Earth rotation, by approximately 25 degrees. Figure 3.7: Four Passes of a LEOSAR Satellite In Figure 3.7 above, at 1200 UTC, the satellite passes over Australia in a near-polar orbit. The orbit can be in either direction (i.e., north to south, or south to north). At 0145 UTC (i.e., 105 minutes later), the satellite has completed a full polar orbit but due to the rotation of the Earth, at 0145 UTC, the satellite is now approximately 25 degrees further west. A LEOSAR satellite covers the surface of the Earth approximately every 12 hours. The LEOSAR constellation has a minimum of four satellites; in June 2022, there were four operational LEOSAR satellites in the constellation. Global, non-continuous coverage of the Earth is achieved. The coverage is not continuous because polar orbiting satellites can only view a relatively small portion of the Earth at any given time. The radius of the footprint is about 3,000 kilometres. Figure 3.8 shows the footprint of a LEOSAR satellite.

3–7

Figure 3.8: Footprint of LEOSAR Satellite (Sarsat-10) The LEOSAR satellites cannot detect distress alerts until the satellite is in a position where it can receive transmission bursts from the distress beacon, in other words, when the beacon is in the footprint of the satellite. The LEOSAR satellites transmit a distress alert that the LEOLUT receives when the LEOLUT is in the footprint of the satellite. Since the LEOSAR satellites also have a SAR Processor, the satellites store distress beacon information and rebroadcast it continuously, so that the stored data can be received by a LEOLUT when the satellite comes within view of the LEOLUT, thereby providing global coverage (with inherent time delays). r = 3,000 km z = 900 km

3–8

Figure 3.9: Global coverage of a LEOSAR satellite In Figure 3.9 above, the footprint of a LEOSAR satellite is shown at two times. The first footprint (on the left) only contains a beacon. The LEOSAR satellite detects the beacon and stores the detection data in its SAR Processor. The second footprint (on the right) shows the satellite at a later time. The footprint contains another beacon and a LEOLUT. The LEOSAR satellite is able to download the detection data from the first beacon using the global coverage provided by the SAR Processor. The second beacon, as it is in the same footprint as the LEOLUT, can be directly relayed to the LEOLUT using the SAR Repeater on the LEOSAR satellite. Detections using the SAR Repeater are known as local detections. The LEOSAR system calculates the location of distress events using Doppler processing techniques. Doppler processing is based upon the principle that the frequency of the distress beacon, as “heard” by the satellite instrument, is affected by the relative velocity of the satellite with respect to the beacon. By monitoring the change of the frequency of the received beacon signal from different beacon transmission bursts, and, knowing the exact position and velocity of the satellite, a LEOLUT is able to calculate two possible locations for the beacon. The two locations are equidistant from the satellite at the time when the satellite was closest to the beacon (the time of closest approach, or TCA).

3–9

Figure 3.10: A Doppler Curve for a Hypothetical FGB In Figure 3.10 above, the plot has the time of detection on the x-axis and the frequency of the detection by the LEOSAR satellite on the y-axis. Each FGB burst (shown with the inverted triangle) occurs approximately every 50 seconds. Due to the Doppler Effect, the beacon frequency is initially detected at a higher frequency than the actual transmitted frequency, and it then decreases as the satellite passes closer to the beacon. When the satellite is at the closest point to the beacon (known as the TCA, or Time of Closest Approach), the frequency matches the actual frequency of the beacon. By analysing the shape of the Doppler curve, a LEOLUT can calculate the distance of the beacon from the satellite at the TCA, this produces two possible locations for the beacon known as the Doppler A-side and Doppler B-side. The two Doppler locations are known as the A-side and the B-side of the Doppler solution; they are also known as the A-position and the B-position. The LEOLUT generates a probability for each of the two Doppler locations taking into account the Doppler effect of the earth’s rotation. Time of Closest Approach

3–10

Figure 3.11: Two Doppler Locations from a LEOSAR Satellite Pass In Figure 3.11 above, note that the two locations (Doppler A and Doppler B) are equidistant from the satellite at the time of closest approach (TCA). The process of determining which of the two Doppler locations is the location of the beacon is known as position confirmation (or ambiguity resolution). The Doppler location that is not the location of the beacon is known as the mirror or image location.

3–11

Figure 3.12: Confirmation by Two LEOSAR Passes In Figure 3.12 above, this example continues the previous Figure 3.11. A second LEOSAR satellite pass has produced two new Doppler locations, Doppler A2 and Doppler B2. The location of the beacon would be confirmed by the matching of Doppler B1 (from the first satellite pass) and Doppler A2 (from the second satellite pass). Both Doppler A1 and Doppler B2 can now be determined to be mirror (image) locations. A LEOLUT may use data from a GEOLUT to help generate the Doppler location for a given beacon. This is known as LEO-GEO processing. A LEOLUT may produce any of four possible forms of data: 1. A beacon detection without location: A beacon is detected but there is no location data associated with the detection. Typically, this is due to the LEOLUT receiving insufficient bursts in order to perform the Doppler processing to produce locations. 2. A beacon detection with a GNSS position. A beacon is detected and there is a GNSS position encoded in the beacon message. 3. Two Doppler locations. A beacon is detected, and using Doppler techniques, the LEOLUT generates two possible estimates of the location of the beacon. The two locations are known as the A-position and the B-position. The LEOLUT will also generate a probability for each of these positions. 4. Two Doppler locations and an encoded GNSS position. A beacon is detected, the beacon message contains a GNSS position, and two Doppler locations are also generated.

3–12

Although a LEOLUT may be able to compute a Doppler location for a beacon that is fast- moving, the accuracy of that location is not expected to meet the requirements of the GADSS for an ELT(DT), and all Doppler locations are filtered for ELT(DT)s. All ELT(DT)s are required to be capable of transmitting a GNSS location in the beacon message, and the GNSS location is considered to be the primary location data for the ELT(DT). 3.3 GEOSAR The GEOSAR satellites orbit the Earth at an altitude of approximately 36,000 kilometres, with an orbit period of 24 hours, thus appearing fixed relative to the Earth at approximately 0- degree latitude (i.e., over the equator). A single geostationary satellite has a footprint with a radius of approximately 7,500 kilometres and provides GEOSAR coverage of about one third of the globe. Due to their positions over the equator, the GEOSAR satellites are unable to detect beacons north or south of about 70 degrees of latitude. Figure 3.13 shows the footprint of the GEOSAR satellite MSG-2. Figure 3.13: Footprint of GEOSAR Satellite (MSG-2) A GEOLUT may produce either of two possible forms of data: 1. A beacon detection: A beacon is detected but there is no GNSS position data associated with the detection. 2. A beacon detection with an encoded GNSS position. A beacon is detected, and the beacon message contains a position generated by the GNSS equipment in the beacon. A GEOLUT has no means to compute an independent location for a beacon. – END OF SECTION 3 – r = 7,500 km z = 36,000 km

4–1

MISSION CONTROL CENTRES Each MCC has a service area and provides beacon alert data to Responsible Agencies within that service area. For example, the Norwegian MCC (NMCC) provides beacon alert data to the Responsible Agencies in the following countries/regions: Denmark, Estonia, Faroe Islands, Finland, Greenland, Iceland, Latvia, Lithuania, Norway, Poland and Sweden. Similar information for all MCCs and their supported Responsible Agencies can be found on the Cospas-Sarsat website. MCCs are organized in a nodal network that allows efficient distribution of beacon alert data around the world. This nodal network is comprised of six Data Distribution Regions (DDRs), in which each DDR has a nodal (or hub) MCC that distributes alerts between other MCCs that are not nodes; see Figure 4.1. MCCs send beacon alert data to a Responsible Agency outside their service area using the MCC nodal network. For example, the Norwegian MCC (NMCC) distributes an alert for the Algerian RCC via the nodal French MCC (FMCC), which then distributes the alert to nodal Spanish MCC (SPMCC), which then distributes the alert the Algerian MCC (ALMCC) which delivers the alert to the Algerian RCC. Figure 4.1: A Schematic View of the MCC Network

4–2

In Figure 4.1 above, there are six Data Distribution Regions (DDRs): the Western DDR (WDDR), the Central DDR (CDDR), the South Central DDR (SCDDR), the North-West Pacific DDR (NWPDDR), the Eastern DDR (EDDR) and the South-West Pacific DDR (SWPDDR). Data distribution between DDR regions is performed by the nodal MCCs. Within the CDDR, all MCCs are able to distribute data directly with other CDDR MCCs; in all other DDRs, data distribution between MCCs in the DDR is also performed via the nodal MCC. An MCC therefore receives beacon alert data from its local LUTs and also from other MCCs. An MCC processes the beacon alert data with the objective of providing timely, accurate and reliable beacon alert data to the relevant Responsible Agencies. The MCC filters out redundant data to ensure that a Responsible Agency is not distracted or confused by unnecessary data. The MCC network and the data processing rules are described in document C/S A.001 known as the Data Distribution Plan (DDP). 4.1 General Principles An MCC follows three basic principles when processing and forwarding data as follows. 4.1.1 Timeliness An MCC provides timely data. The MCC does not wait for additional data before sending data. For example, if an MCC receives a beacon detection with no location, the MCC does not wait before sending to a Responsible Agency, just in case no more data is received. Instead the MCC would forward the beacon detection data to the Responsible Agency and, if more data is received, would send the additional data to the Responsible Agency later. For aircraft distress tracking, ICAO requires that location data be provided at least once a minute while the aircraft is in a potential distress situation. For this reason, all ELT(DT) location data is forwarded to the associated MCC for processing. 4.1.2 Redundancy An MCC attempts to minimize redundant data sent. For example, if an MCC receives a GNSS position for a beacon, it will forward that location to the appropriate Responsible Agency. If the MCC receives another beacon detection with no location data (e.g., from another satellite), it will normally not forward that data to the Responsible Agency. If the MCC received another detection with the same GNSS position, it would similarly not forward this redundant location data. As another example, if an MCC receives Doppler position data from two LEOLUTs for satellite S-13 with the same TCA for the same beacon, then the MCC will not send the second Doppler solution unless it has reason to believe that the new data may be of better quality.

4–3

An MCC will send updates that would otherwise be considered redundant to allow a Responsible Agency to know that a beacon is still active. For example, MEOSAR position data will be sent every 15 minutes after position confirmation for beacons other than ELT(DT)s, even if the latest detection does not provide better quality data. 4.1.3 Confirmation: Beacon position data is unconfirmed until it has been confirmed on the basis of information provided by two independent sources. Position confirmation requires that two positions for a beacon are from independent sources and match within 20 kilometres of each other, as specified in document C/S A.001. An MCC reference position is an approximation of the beacon position generated or selected by the MCC, based on a match of positions from independent sources within 20 kilometres. The MCC reference position is used as the reference position to determine if subsequent position data is deemed a position update or a position conflict, based on the 20-kilometre distance threshold match. The MCC reference position may be further updated based on new position data that matches the current MCC reference position within 20 kilometres. A reference to a “position confirmed” alert or “position confirmation” in this document does not imply that any specific position provided in the associated alert message is the actual beacon position. Further information on the use of position data included in the alert message is provided in section 5.4. Two locations are independent if they are two different types of location, or for two Doppler locations or for two DOA locations, if they are derived from different beacon events, as outlined in the following table. Table 4.1: Determining if Two Locations for a Beacon are Independent GNSS Doppler DOA GNSS No Yes Yes Doppler Yes Different satellites or time (TCA) difference of at least 20 minutes* Yes DOA Yes Yes Each satellite set has a unique satellite or a time difference of at least 30 minutes

• Two pairs of Doppler locations are not independent if each Doppler location matches a Doppler location in the other solution; see “Unresolved Doppler Match” Section 4.2.6. Note that the independence of two encoded GNSS position cannot be determined as the two positions come from the same source, i.e., the GNSS unit on (or attached to) the beacon. Section 7.22 provides clarifying examples of independence. Position is not confirmed for ELT(DT)s, which are assumed to be fast-moving.

4–4

4.2 MCC Messages The following sections describe the message types sent to a Responsible Agency by an MCC. The complete messages are described in section 5, and examples are provided in section 6. 4.2.1 Initial Alert (Unlocated) and Initial Location Alert An initial alert indicates that a beacon has been detected. An initial alert with no location information is known as an unlocated beacon alert and its message type is “INITIAL ALERT (UNLOCATED)”. An unlocated beacon alert is sent to the Responsible Agencies associated with the country of registration contained in the beacon message. Although an unlocated beacon alert has no location data, the beacon message provides useful data to a Responsible Agency. The beacon message contains the Hex ID of the beacon. If the beacon is registered in the country’s beacon registration database or the IBRD, the owner and emergency contacts can be determined. As well, some beacon messages contain the MMSI of a vessel or a call sign of an aircraft which allows the Responsible Agency to contact the vessel or aircraft associated with the beacon. The message type for the first alert with location is “INITIAL LOCATED ALERT”, unless there is a “position conflict” as described in section 4.2.3. The first located alert may contain an MCC reference position, if the alert contains a GNSS position that matches a Doppler or DOA position, as discussed in section 4.2.2. The Responsible Agency informed of alerts with location data depends on the type of beacon. For ELTs, EPIRBs and PLBs the location data is used to determine the SAR Service informed of the alert. For SSAS beacons the location data does not affect the Competent Authority informed as only the Competent Authority associated with the country of registration is informed of an SSAS beacon activation. For an ELT, EPIRB or PLB, an MCC sends an initial located alert to any SAR Service relevant to the unconfirmed location data contained in the alert. For example, if a LEOLUT generates two Doppler locations for a New Zealand EPIRB, one in the Fiji RCC service area and another in the New Zealand RCC service area, the Australian MCC will send an initial alert to both the Fiji RCC and the New Zealand RCC.

4–5

Figure 4.2: Two Doppler Locations from a LEOSAR Satellite Pass for an EPIRB In the Figure 4.2 above, (that also appeared as Figure 3.11), a LEOSAR satellite has produced two Doppler locations (Doppler A and Doppler B) for a New Zealand EPIRB. As the Doppler A position is in the Fiji service area, the Fiji RCC will be sent an initial alert with both Doppler locations. As the Doppler B position is in the New Zealand service area, the New Zealand RCC will be sent an initial alert with both Doppler locations. Prior to position confirmation, every located alert is sent to each Responsible Agency that previously received an alert for the beacon activation, as well the Responsible Agencies responsible for a location in the new alert. This enables all involved Responsible Agencies to coordinate a response. A Responsible Agency may be able to use the unconfirmed location data along with other information in responding to the incident. For example, additional information from a phone call to an emergency contact using the beacon registration details or a flare sighting near an unconfirmed location may assist the tasking of resources. 4.2.2 Position Confirmed Alert A position confirmed alert contains an MCC reference position, which is the result of two matching independent locations, as described in section 4.1.3 above. When a position is confirmed, the message type is “POSITION UPDATE ALERT” if an alert with position information was previously sent, or “INITIAL LOCATED ALERT” if no position information was previously sent. The presence of an MCC reference position indicates that position is confirmed.

4–6

A position confirmed alert is sent to all Responsible Agencies that have received alert messages about the beacon activation. For example, if an initial alert from an EPIRB is sent to the Fiji RCC and the New Zealand RCC as the alert had two Doppler locations generated by a LEOLUT, when the location is confirmed as in New Zealand, the alert will be sent to both the Fiji RCC and the New Zealand RCC. The position confirmed alert informs the Fiji RCC that the beacon position has now been confirmed to be outside the Fiji RCC service area. Figure 4.3: Confirmation of LEOSAR Data by a MEOSAR Detection In the Figure 4.3 above, DOA location data from the MEOSAR system has confirmed the beacon location with the Doppler B1 location. As MCC reference position is in the service area of New Zealand, the New Zealand RCC will be sent the alert. As an initial alert had been sent to the Fiji RCC due to the earlier Doppler A1 location, the alert will also be sent to the Fiji RCC. The first alert sent from an MCC to a Responsible Agency provides an MCC reference position when the first alert contains position data (DOA or Doppler) and a matching GNSS position. The method used by the MCC to generate the MCC reference position from the matching independent locations is not defined by Cospas-Sarsat. Instead, the specifications state that this position may be formed by a merge of matching locations which may be based on a weighting factor assigned to each matching location. Each Responsible Agency

4–7

should consult with its supporting MCC to obtain information on the method used to generate the MCC reference position by that MCC. Position is not confirmed for ELT(DT)s, which are assumed to be fast-moving. If an ELT(DT) alert is sent with matching GNSS and DOA positions, then the message type is “DOA POSITION MATCH”. 4.2.3 Position Conflict Alert Except for ELT(DT)s, if an MCC receives new location data that does not match any of the previous location data for that beacon within 20 kilometres, then the new location data is labelled as “in conflict”. For ELT(DT)s, position data in previous alerts is not referenced in the processing of new position data, thus a position conflict can only occur for an ELT(DT) if the GNSS and DOA positions in the new alert are “in conflict”. The MCC filters some conflict data (for example, if the new location data is of lesser quality) but otherwise sends a position conflict alert to indicate that the new location data does not match previously sent location data. A fast-moving beacon (for example, on an aircraft) other than an ELT(DT) will typically generate an initial alert followed by a series of conflict alerts, as all the alerts after the initial alert will not match. The trail of conflicts may provide a path for the fast-moving beacon. It is possible for a Responsible Agency to receive a conflict alert as the first message. For example, if an MCC receives a DOA location and a GNSS position as the first alert for a beacon, and if the DOA location and the GNSS position do not match, the MCC will send a conflict message to the relevant Responsible Agencies. Prior to position confirmation, for ELTs, EPIRBs and PLBs, if non-matching locations are in the area of responsibility of different SAR Services, all the SAR Services would receive a conflict alert. 4.2.4 Position Update Alert An MCC will send an update alert if it receives beacon detection data that is not redundant. Cospas-Sarsat has a very detailed definition of when an update is sent, but from the Responsible Agency perspective, an update will be sent when the MCC has additional data or better-quality data, or to indicate that the beacon is still active and transmitting. An update can be sent before and after confirmation of the location. Prior to position confirmation, a new alert with DOA position that is otherwise redundant will be sent every five (5) minutes for all beacon types except ELT(DT)s. To prevent too many MEOSAR alerts from being sent to a Responsible Agency after position confirmation, a MEOSAR alert with DOA position matching the MCC

4–8

reference position that is not better quality will only be sent every 15 minutes. A MEOSAR alert with DOA position that does not match the MCC reference position and is not better quality will only be sent every ten (10) minutes. An alert with a better- quality DOA position (based on the expected horizontal error) is always sent, as specified in document C/S A.001. Position is not confirmed for ELT(DT)s, which are assumed to be fast-moving. For all beacon types except ELT(DT)s, an updated alert with GNSS position is sent if the new GNSS position differs from previously sent GNSS position by three (3) to twenty (20) kilometres or, for an FGB, if the new GNSS position is refined (i.e., more precise) and no previous GNSS position was refined. In general terms, a new alert for an ELT(DT) is sent to the Responsible Agency every five (5) seconds within the first 30 seconds after beacon activation. More specifically, if the “reference” detection time of the new ELT(DT) alert is within 30 seconds of the earliest “reference” detection time received, then the alert is sent if: a) no other alert has been sent with a reference time within three (3) seconds of the new alert’s reference time; or b) the new alert has GNSS position (and no other alert with GNSS position has been sent with a reference time within three (3) seconds of the new alert’s reference time); or c) the new alert has DOA position (and no other alert with DOA position has been sent with a reference time within three (3) seconds of the new alert’s reference time). Note that ELT(DT)s transmit every five (5) seconds for the first 120 seconds after activation, so the three (3)-second threshold noted above effectively results in alerts being every five (5) seconds. The new alert is also sent if, based on service area information available to the MCC, it contains DOA or GNSS position located in a service area for which the Responsible Agency has not previously been sent an alert. In addition, if the current reference (detection) time is at least ten (10) minutes more recent than the reference time for all previously sent alerts, then the MCC sends the “best” solution with a reference time more recent than the reference time for all previously sent alerts, where the priority is given to a GNSS position (SGB) or refined GNSS position (FGB). Until MCCs have implemented distribution of the “best” new solution, they send a new alert with GNSS or DOA position, if the new reference time is at least ten (10) minutes after the reference time for all previously sent alerts. 4.2.5 Notification of Country of Beacon Registration Alert A Notification of Country of Registration (NOCR) alert is sent to the SAR Service associated with the country of registration in the beacon message. An NOCR is not sent to the Competent Authority for an SSAS alert as all SSAS alert messages are sent to the

4–9

Competent Authority associated with the country of registration and hence there is no need for an NOCR alert. For example, if a PLB with a country of registration of New Zealand is detected outside the New Zealand Search and Rescue Region (SRR), the RCC in New Zealand will be sent an NOCR alert. An MCC that processes an ELT, EPIRB or PLB location in its service area will generate the NOCR and send the NOCR through the MCC network as required. An NOCR alert is similar to an unlocated alert in that both alerts are sent based on the country of registration. However, an NOCR alert is only sent when there is a location associated with a beacon; an unlocated initial alert is sent when there is no location associated with the beacon. An NOCR alert permits a SAR Service to commence a search for beacon registration details before a request is received from the SAR Service that is responding to the beacon incident. It also enables the national SAR Service in the country of registration to offer assistance, as appropriate, for the rescue of their fellow citizens. 4.2.6 Unresolved Doppler Position Match Alert An Unresolved Doppler Position Match occurs when the two Doppler locations from one beacon event match the two Doppler locations from another beacon event prior to position confirmation. Since neither Doppler location can be ruled out as the actual position, neither of the two Doppler locations is confirmed by the second pair of Doppler locations. Figure 4.4 shows an unresolved Doppler match that occurred in 2011. One LEOSAR satellite, Sarsat S-08, tracked on the red path and produced two Doppler locations (shown as purple dots). LEOSAR satellite Sarsat-11 tracked on the purple path at a later time and produced two Doppler locations (shown as red dots). The unresolved Doppler match does not confirm a location (as both of the two possible locations are still potentially valid). Note that in 2011 the matching distance for position matches was 50 kilometres; but has since changed to 20 kilometres.

4–10

Figure 4.4: Example of an Unresolved Doppler Match 4.2.7 Interferer Alert Some MCCs transmit 406 MHz interferer alerts to SAR Services using the SIT 185 message format. The International Telecommunication Union (ITU) has allocated the 406 MHz band for low power distress beacons. Nevertheless, there are unauthorised signal sources in various areas of the world radiating in the 406.0 – 406.1 MHz range. Interferers degrade the performance of the Cospas-Sarsat System and reduce the ability of the System to detect and locate real beacon messages. Suitably equipped LUTs in the Cospas-Sarsat System are used to detect and locate the source of some of these interferers. Unlike the processing of 406 MHz digital beacon signals, no identification code is available from an interferer. An interfering source can only be identified by determining its location. Persistent interferers are reported by MCCs to ITU through their national spectrum management agencies. 4.2.8 User Cancellation Alert A user cancellation message is sent when three separate cancellation messages have been received from the beacon with detect times within 110 seconds, with no intervening non- cancellation messages. The FGB and SGB specifications require that the user cancellation function only be activated by the same source that originally activated the beacon.

4–11

4.3 Alerts with Invalid or Suspect Data In some cases, the beacon detection data or location data is invalid or may be inaccurate for various reasons. The SIT 185 message sent to a Responsible Agency by an MCC will indicate these situations. 4.3.1 Transmissions with an Invalid Beacon Message The data transmitted in the message from a distress beacon includes error-correcting codes that allow a LUT to detect and to fix some errors in the data. If there are too many errors in the beacon message, the LUT cannot correct the errors and the message is treated as invalid. As well, for all beacon messages that the LUT receives correctly, the MCC performs additional validation of the beacon message and if data has invalid values (e.g., an invalid country code), the whole beacon message is also treated as invalid. An MCC will send the Hex ID associated with an invalid beacon message, but the Responsible Agency should note that the Hex ID is unreliable and should be treated with caution. Other data, including GNSS position data, from the beacon message is not sent to the Responsible Agency as the data may be invalid. A beacon alert with an invalid beacon message does include the DOA or Doppler position data. Even if the beacon message is invalid, the DOA and Doppler location data are still reliable. 4.3.2 Suspect Doppler Locations Doppler locations may be suspect for a number of reasons. An MCC will note any such Doppler locations when sent to a Responsible Agency. If the LEOSAR satellite that detected the beacon has recently completed a satellite manoeuvre, the location of the satellite in space may be different from the location used by the LEOLUT to calculate the Doppler locations. Doppler locations with a detect time (TCA) within 24 hours after a satellite manoeuvre are noted as suspect when sent, if the expected location error resulting from the manoeuvre may exceed ten (10) kilometres. The LEOLUT calculates the Doppler locations using time and frequency data from the satellite. Factors that contribute to the quality of the locations produced include the number of beacon bursts, the angle of the satellite to the beacon and the relationship of the TCA to the timing of the bursts. Any Doppler locations generated by poor quality data are noted as suspect and should be treated with caution by a Responsible Agency. An MCC performs a satellite footprint check on all locations. The footprint check ensures that any location associated with an alert was visible to the satellite(s) that reported the beacon. The footprint check uses a minus five (5) degree elevation in its calculation to provide some assurance that the location is indeed outside of the footprint. If the MCC determines that one of the Doppler locations in a LEOSAR detection is outside the footprint of the LEOSAR satellite that detected the beacon, the message sent will note that the location data is suspect.

4–12

4.3.3 Uncorroborated MEOSAR Alerts A MEOSAR alert detected by only a single satellite and only a single beacon burst with no previous alert for the beacon activation that contains data from a different beacon burst or satellite is deemed uncorroborated and is treated as suspect. Normally these uncorroborated detections are only sent to a Responsible Agency if: a) the beacon is a Distress Tracking ELT (ELT(DT)); b) the reporting MEOLUT meets relevant requirements for generating processing anomalies; or c) it is known that the beacon ID associated with the MEOSAR alert is registered. If such a detection is sent to a Responsible Agency, the message will note that this is a single uncorroborated detection and note if the associated beacon ID is registered. Such alerts should be treated with caution since they may not correspond to actual beacon transmissions. The validity of an uncorroborated MEOSAR alert (i.e., the validity of the associated beacon ID and/or encoded position) can be substantiated by the presence of corroborating information, such as: a) another alert for the same beacon ID; b) beacon registration data for the specific beacon ID (and information provided about the use of the beacon by the point of contact identified in the beacon registration); c) a vessel or aircraft ID in the alert message (and related registration information for this ID); or d) correlation between the beacon type indicated on the alert message and the beacon type(s) designated for the associated Type Approval Certificate (TAC) number (if a TAC number is provided on the alert message). Relevant information for “Type Approval Certificate Numbers” is located on the Cospas-Sarsat website https://www.cospas-sarsat.int/en/beacons-pro/experts- beaconinformation/approvedbeacon-models-tacs?view=tac_beacons. 4.3.4 Suspect DOA Locations DOA locations provided include an estimate of accuracy. For example, a DOA location with an accuracy estimate of 20 nautical miles should be within 20 nautical miles of the beacon, 95% of the time. Any DOA location with a large accuracy estimate should be treated with caution. If a satellite footprint check indicates that the DOA location is outside the footprint of any of the MEOSAR satellites that detected the beacon, the message sent will note that the location is suspect.

4–13

4.3.5 Suspect GNSS Positions A GNSS position that fails the satellite footprint check is suppressed and is not transmitted.

• END OF SECTION 4 -

5–1

COSPAS-SARSAT DISTRESS MESSAGES An MCC sends beacon alerts to Responsible Agencies in SIT 185 format. A SIT (Subject Indicator Type) 185 is a plain text message with information regarding the beacon activation. Examples of SIT 185 messages are presented and analysed in section 6. Figure 5.1 contains an example SIT 185 message for an FGB. 080401Z JAN 2017 FROM AUMCC TO RCC WELLINGTON BT

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 12590 AUMCC REF C00F429578002C1
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER – PLB SERIAL NO 0042334 HEX ID C00F429578002C1 COUNTRY OF BEACON REGISTRATION 512/NEWZEALAND BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 08 JAN 17 0354 UTC BY SARSAT 10 GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A - 41 14 S 172 31 E PROB 79 PERCENT DOPPLER B - 48 20 S 135 51 E PROB 21 PERCENT
5. OTHER INFORMATION DETECTION FREQUENCY 406.0282 MHZ TAC NO 0176 BEACON MODEL – STANDARD COMMS, AUSTRALIA MT410, MT410G
6. REMARKS NIL END OF MESSAGE Figure 5.1: A Sample SIT 185 Message SIT 185 messages may include a preamble. The format of the preamble is determined by the sending MCC. In Figure 5.1, the four-line preamble includes the day and time of transmission in UTC and the identification of the originating MCC (AUMCC) and recipient (the RCC Wellington). The characters BT (for Begin Transmission) indicate the end of the preamble in the sample message above. As the format of the preamble is dependent on the MCC and is not part of the formal specification for SIT 185 messages, no preamble will be shown in following examples of SIT 185 messages.

5–2

When information with respect to a message field is not available, or is unknown or irrelevant, dependent upon the message type and beacon protocol, the distress message will indicate “NIL” for that message field, or, for certain message fields, the message field may be omitted. A Cospas-Sarsat SIT 185 message consists of six (6) paragraphs. Table 5.1 lists the paragraphs of a SIT 185 message. Table 5.1: Message Content for SIT 185 Messages PARAGRAPH# TITLE 1. MESSAGE TYPE M 2. CURRENT MESSAGE NUMBER M MCC BEACON REFERENCE M 3. BEACON MESSAGE INFORMATION M TYPE OF BEACON O IDENTIFICATION O BEACON HEX ID M COUNTRY OF BEACON REGISTRATION O BEACON NUMBER O HOMING SIGNAL O ACTIVATION TYPE O SOURCE OF GNSS POSITION DATA O EMERGENCY CODE O 4. ALERT POSITION INFORMATION M DETECTION TIME & SPACECRAFT M GNSS POSITION, TIME OF UPDATE AND ALTITUDE O MCC REFERENCE POSITION O DOA POSITION AND ALTITUDE O A POSITION & PROBABILITY O B POSITION & PROBABILITY O 5. OTHER INFORMATION M DETECTION FREQUENCY M OTHER ENCODED INFORMATION O 6. REMARKS M END OF MESSAGE M Notes:

1. "M" means that the field is mandatory
2. "O" means that the field may be omitted if the value is NIL. 5.1 Paragraph 1: Message Type For an alert from a ship security (SSAS) beacon, the message type begins with “SHIP SECURITY COSPAS-SARSAT”. For an alert from a Distress Tracking ELT (ELT(DT)), the message type begins with “DISTRESS TRACKING COSPAS-SARSAT”.

5–3

For all other beacon types, the beacon alert message type begins with “DISTRESS COSPAS- SARSAT”. The message types are described in section 4.2 and are listed here: • “INITIAL ALERT (UNLOCATED)” • “INITIAL LOCATED ALERT” • “POSITION CONFLICT ALERT” • “DOA POSITION MATCH ALERT” • “POSITION UPDATE ALERT” • “NOTIFICATION OF COUNTRY OF BEACON REGISTRATION ALERT” • “USER CANCELLATION ALERT” • “UNRESOLVED DOPPLER POSITION MATCH ALERT” • “ROTATING FIELD UPDATE ALERT” • “UPDATED ALERT UNLOCATED” 5.2 Paragraph 2: Current Message Number and MCC Beacon Reference The current message number is a sequential message number assigned by the transmitting MCC to each message sent to a specific Responsible Agency. Responsible Agencies should ensure that they do not miss any message numbers. The MCC beacon reference is a unique designator supplied by the MCC to identify all messages sent for that beacon. Some MCCs use an integer and other MCCs use the beacon 15 Hex ID for this message field. Responsible Agencies wishing to discuss a particular alert with an MCC can assist the MCC by quoting the message number and the MCC reference designator of the alert. 5.3 Paragraph 3: Beacon Message Information This paragraph provides key information about the beacon derived from the 406 MHz beacon message. Any message field in this paragraph with a value “NIL” may be omitted. If the beacon message is invalid, then the only message field provided without a “NIL” value in this section is the Hex ID and the following note is included: “DATA DECODED FROM THE BEACON MESSAGE IS NOT RELIABLE” 5.3.1 Type of Beacon The beacon type is the general category of the beacon protocol used to code the beacon. The protocol is provided as well as any identification fields. For example, the last six digits of the MMSI are shown for beacons coded with an EPIRB-MMSI protocol.

5–4

It should be noted that some beacons are coded inappropriately for the environment in which they are used. For example, there have been real world examples of EPIRBs being used as PLBs in the Himalayan Mountains. Some countries allow PLBs to be coded with an ELT protocol for use on an aircraft. Examples of the different identification fields are shown in the following sections. 5.3.1.1 Serial Number A serial number is assigned by the country of registration. The serial number does not provide any further identification by itself; the relevant beacon database of the country of registration must be searched for further details. BEACON TYPE USER LOCATION – EPIRB (NON FLOAT FREE) SERIAL NO 0106717 5.3.1.2 Aircraft Operator Designator and Serial Number Aircraft operator designators are provided by ICAO in the airline designators document, published as ICAO document 8585 – “Designators for Aircraft Operating Agencies, Aeronautical Authorities and Services”. These designators are 3-letter codes like BAW for British Airways or QFA for QANTAS. Each operator designator can have a serial number from 1 to 4095. BEACON TYPE STANDARD LOCATION – ELT AIRCRAFT OPERATOR DESIGNATOR AND SERIAL NO QFA 0543 5.3.1.3 Aircraft 24-Bit Address The ICAO 24-bit aircraft address is allocated to States to uniquely identify aircraft worldwide. The Appendix to Chapter 9 of the ICAO Annex 10, Aeronautical Communications document provides the worldwide scheme for the allocation, assignment and application of aircraft addresses. The 24-bit address is presented as six hexadecimal characters in the Cospas-Sarsat distress alert message. BEACON TYPE STANDARD LOCATION – ELT AIRCRAFT 24-BIT ADDRESS 7C5E8A ASSIGNED TO AUSTRALIA 5.3.1.4 Radio Callsign The Radio callsign allocations can be obtained from the ITU website: www.itu.int. BEACON TYPE USER LOCATION - EPIRB RADIO CALLSIGN VHN-259

5–5

5.3.1.5 MMSI The “all” nine-digit MMSI is formed by adding the country code provided in the country of registration field to the six trailing digits provided in the “MMSI” vessel identification field. BEACON TYPE STANDARD LOCATION - EPIRB MMSI ALL 9 DIGITS 563004940 HEX ID 4664026980FFBFF COUNTRY OF BEACON REGISTRATION 563/SINGAPORE In the above example, the “all” nine-digit MMSI is 563004940 composed of the country code 563 and the six trailing digits 004940. 5.3.1.6 MMSI with AIS ID The SGB message may contain a MMSI and an automatic identification system (AIS) ID. The AIS is an automatic tracking system that uses transceivers on ships to improve maritime safety. The AIS ID always has a prefix of “974”, which is not encoded in the SGB message. A sample is provided below. BEACON TYPE - EPIRB MMSI 366123456 EPIRB-AIS ID 974 0123 TAC 12260 SERIAL NO 13750 HEX ID ADD4BF935B61 574A670007B COUNTRY OF BEACON REGISTRATION 366/USA 5.3.2 Identification Other information may be decoded from the 406 MHz message and may be used by the servicing MCC to provide information with respect to an aircraft 24-bit address country assignment and its registration marking. AIRCRAFT 24-BIT ADDRESS 7C5E8A ASSIGNED TO AUSTRALIA 5.3.3 Beacon Hex ID The Hex ID is the 15 character hexadecimal representation of a beacon identification code as described in section 2.4. 5.3.4 Country of Beacon Registration The three-digit country code, based on the list provided by the International Telecommunication Union (ITU) is provided, followed by the name of the country of beacon registration. A list of the three-digit country codes is given at Annex B of this document and is also provided on the Cospas-Sarsat web site (www.cospas-sarsat.int).

5–6

5.3.5 Beacon Number For the first beacon on board the vessel or aircraft, the message field will be identified as zero (0). Other beacons on board the vessel or aircraft will be identified as 1 to 63 and A to Z. All the other programmed information will remain the same (e.g., MMSI, Radio Callsign, Aircraft Identifier, etc.). Different protocols will allow different numbers of beacons to be recorded. 5.3.6 Homing Signal Homing Signal Interpretation: • “NIL”, means no homing transmitter, • “121.5”, means a 121.5 MHz homing signal in addition to the 406 MHz satellite signal, • “MARITIME”, means Maritime 9 GHz Search and Rescue Radar Transponder (SART) in addition to 406 MHz, • “NIL OR NOT 121.5”, means no homing transmitter or homing transmitter other than 121.5 MHz • “OTHER”, means a nationally assigned homing signal has been included in the beacon. 5.3.7 Activation Type A beacon can be activated either manually or automatically. The activation type provides information with respect to the switching mechanism built into the beacon; i.e., some beacons can only be activated manually, and others can be activated automatically or manually. For example, a float-free EPIRB will indicate “automatic or manual” activation in the distress alert message, an ELT (including an ELT(DT)) can be either activated automatically because of a strong acceleration or deceleration on the “G” sensor, or manually by the crew in the cockpit. An ELT(DT) can also be activated due to the aircraft avionics detecting an anomalous condition, in which case the activation type indicates “AUTOMATIC BY EXTERNAL MEANS (AVIONICS)”. Ship security alert messages always indicate “MANUAL” activation as SSAS beacons can only be activated manually. The type of beacon activation is not available in all beacon coding protocols. For FGB User Protocol beacons, this information is not protected, i.e., is not subject to automated error detection and correction, and thus should be treated with caution.

5–7

5.3.8 Source of GNSS Position Data This message field indicates whether the GNSS location data was provided to the beacon by an internal or external GNSS device. The update rate for a beacon with an internal GNSS device depends on the model of beacon. (See also sections 2.7 “GNSS Positions” and 5.4.7 “Summary Guidance for the Use of Position Data”). Regardless of a beacon model’s designed GNSS position update period, its GNSS position may not be updated if the beacon’s visibility to GNSS satellites is significantly obstructed. An FGB designed to accept position data from an external device prior to beacon activation should be provided with position data by the external device at intervals not longer than 20 minutes for EPIRBs and PLBs and 1 minute for ELTs. If the navigation input fails or is not available, the FGB will retain the last valid position for four (4) hours after which the GNSS position will be set to default values. SGB ELT(DT)s retain the last valid GNSS for 24 hours after which the GNSS position will be set to default values. Note: If the beacon receives its encoded location from an external navigation system, it is possible that this location may have been derived from a source that is not a satellite (GNSS) navigation system. 5.3.9 Emergency Code A provision exists in some beacon coding protocols to indicate the nature of distress in accordance with the International Maritime Organisation (IMO) maritime emergency codes. These codes can indicate “Fire/Explosion”, “Flooding”, “Collision”, “Grounding”, “Listing”, “in Danger of Capsizing”, “Sinking”, “Disabled and Adrift” or “Unspecified Distress”. A provision also exists in the beacon coding to indicate non-maritime emergencies, and these include an indication of a fire, if medical assistance is required, or if disabled. This message field is not protected; i.e., it is not subject to automated error detection and correction. As a consequence, the information provided for this message field should be treated with caution. Currently there are no beacons type-approved with this capability and in most cases no emergency code is available. However, there are some beacons that have been coded by default to indicate “unspecified distress”.

5–8

5.4 Paragraph 4: Alert Position Information Detection information (including detection time and satellite) and position information associated with the beacon alert is provided in Paragraph 4. 5.4.1 Detection Time and Spacecraft ID For MEOSAR alerts, the detection time provided with the prefix “DETECTED AT” is the time of the first burst. As a MEOSAR detection may be detected by many satellites, the Spacecraft ID is shown as “MEOSAR”. As the alert may be a multi-burst detection, the time of the last MEOSAR burst in this alert is on the following line. For LEOSAR alerts with Doppler location, the detection time is the time of closest approach (TCA) of the satellite to the beacon. Note that the actual time that the LEOSAR satellite first detected the beacon can be either slightly before or after the TCA, but the TCA provides a common point in time for processing. The time is followed on the same line by “LEOSAR” and the identity of the satellite which provided the alert data. The LEOSAR satellites are identified as Sarsat or Cospas. For a combined LEOSAR- GEOSAR solution, the identity of the LEOSAR satellite is given. For LEOSAR alerts without Doppler location, the detection time is the time of the last beacon burst. For GEOSAR alerts, the detection time is the time of the first beacon burst. The time is followed on the same line by “GEOSAR” and the identity of the satellite which provided the alert data. The GEOSAR satellites are identified as GOES (Geostationary Operational Environmental Satellite; USA), MSG/MTG (Meteosat Second/Third Generation; EUMETSAT), Electro-L and Louch-5 (Russia), and INSAT and GSAT (India). Except for a MEOSAR alert with matching first and last detection times on the alert message, an alert may include multiple bursts, in which case it cannot be assumed that the GNSS position for an ELT(DT) was computed at the reported detection time. 5.4.2 Position Information (General) An example of position information is shown below: 4. ALERT POSITION INFORMATION GNSS - NIL MCC REFERENCE - NIL DOA - 05 10.1 S 178 01.4 E ESTIMATED ERROR 002 NMS ALTITUDE NIL DOPPLER A - NIL DOPPLER B - NIL

5–9

There may be multiple locations shown in this field. A position confirmed alert will have an MCC reference position and will also show the locations from the most recently processed detection used to confirm the location. Similarly, a position update alert sent after the position confirmation will have the current MCC reference position and will also show the locations from the most recently processed detection. Noting that the uncertainty of a refined GNSS position is two (2) seconds of latitude and longitude (about 60 metres at the equator), a refined GNSS position is generally the most accurate position for a beacon, provided that the GNSS position has been updated recently or the beacon is not moving. Further information about GNSS position updates is provided in section 5.3.8. In accordance with document C/S A.001, a refined GNSS position is not confirmed (i.e., not confirmed as representing the actual beacon position) until it matches a Doppler or DOA position within twenty (20) kilometres; this requirement for a match with position data from an independent source addresses the possibility that the initial GNSS position after beacon activation may be inaccurate (e.g., provide a previously computed GNSS position) due to a beacon malfunction. Summary guidance for the Use of Position Data is provided in section 5.4.7. Section 6 provides examples of real distress alerts and illustrates how the position data is shown in this field. If the value for a specific position field is “NIL”, then the associated data line may be omitted from the alert message. 5.4.3 GNSS Position, Time of Update and Altitude The GNSS field is the latitude and longitude of the GNSS position. The GNSS update time for an FGB is always shown as “within 4 hours of detection time” as the system does not record the time that the GNSS position was generated. If a GNSS position of the FGB has not updated within four hours on a beacon, the beacon stops transmitting the GNSS position (and would be shown as “NIL” in the GNSS field). As discussed in section 2.7, the precision of the GNSS position is dependent on the FGB protocol used and whether a fine or coarse GNSS position is received by the LUT. For SGBs, information about time of the GNSS location is provided, if available: • for ELT(DT)s, “TIME OF GNSS POSITION UPDATE:” followed by the update time, • otherwise, “TIME SINCE GNSS LOCATION GENERATED: [nn] MINUTES”. For SGBs and FGB ELT(DT)s, if the altitude is available, it has the title “ALTITUDE OF GNSS LOCATION” and is provided in both metres and feet. If GNSS position currency information is available for an FGB ELT(DT), then the following text is included: “UPDATE TIME WITHIN [AAAA] OF DETECTION TIME” where “[AAAA]” is: •

• “0 - 2 SECONDS”,

5–10

•

• “2 - 60 SECONDS”, or •
• “1 MINUTE TO 4 HOURS” 5.4.4 MCC Reference Position If there is an MCC reference position, the latitude and longitude are provided. This position may be formed by a merge of matching locations, which may be based on a weighting factor assigned by the MCC to each matching location. 5.4.5 DOA Position and Altitude The DOA field provides the latitude and longitude of the DOA location, the estimated error (i.e., expected accuracy) of the DOA location in nautical miles, and the altitude of the DOA location from the mean sea level in metres. If the estimated error value is greater than 277.8 kilometres (150 nautical miles), the error is shown as “OVER 150 NMS”. If the estimated error is not available or the reporting MEOLUT is not commissioned to meet MEOSAR IOC requirements for DOA position accuracy and the reliability of the expected horizontal error (EHE) as specified in document C/S T.020, then the estimated error is shown as “UNKNOWN”. Further information about the DOA position expected accuracy is provided in section 3.1 above. The DOA altitude is not verified as part of MEOLUT commissioning and is indicated by “NIL” or omitted. 5.4.6 Doppler A and B Positions and Probability The “DOPPLER A” and the “DOPPLER B” fields provide any Doppler locations and their probabilities. Further information about the reliability and expected accuracy of Doppler location data is provided in Paragraph 5. 5.4.7 Summary Guidance for the Use of Position Data GNSS Position The GNSS position is transmitted by the beacon and determined by a navigation source in, or connected to, the beacon (such as aircraft/vessel navigation consoles). The GNSS position uncertainty that is provided in the “OTHER INFORMATION” section of the alert message may vary, as per section 2.7 above. The GNSS position transmitted in a beacon distress message might be a stale/old position if the beacon subsequently becomes detached from an external navigation source providing the position to the beacon. Note: The GNSS position is primarily derived from global navigation satellite systems (such as GALILEO, GPS, GLONASS, BDS, etc.) but could, on some occasions, include

5–11

positions from other external, non-GNSS based systems, which may be subject to degradation of accuracy over time. MCC Reference Position An approximation of the beacon position estimated or selected by the MCC, based on a match of positions from independent sources within 20 kilometres. The MCC Reference position is used to determine if subsequent position data is deemed a position update or a position conflict, based on the 20-kilometre distance threshold match. The MCC reference position may be further updated based on new position data that matches the current MCC reference position within 20 kilometres. There is no standard algorithm for computing the MCC Reference position; contact the associated MCC for further information about its algorithm DOA Position A position computed by a MEOLUT, based on signals received from multiple MEOSAR satellites relaying the same beacon transmissions. A MEOLUT can normally provide a position from a single beacon transmission. MEOLUTs typically calculate an estimated error for each position, which is the radius of the circle that is centered on the estimated location and contains the true location with a probability of about 95%. When the estimated error is not available, then in the case of a stationary beacon, the positions shall meet the following accuracy requirements: a) at least 90% should be within five (5) kilometres, from a single beacon transmission; and b) at least 95% should be within five (5) kilometres, after ten (10) minutes of beacon transmissions. When a DOA location is computed from a single beacon transmission, then the two detection times provided in Paragraph 4 of the alert message are the same. Finally, the beacon altitude may also be provided by the MEOLUT. The DOA altitude is not verified as part of MEOLUT commissioning and is set to “NIL” or omitted until further notice. Doppler Position A Doppler position is computed by a LEOLUT based on signals received from a LEOSAR satellite. If a Doppler position is provided without the “SUSPECT” reliability warning (in the “OTHER INFORMATION” section of the alert message), the Doppler position should be accurate within five (5) kilometres 95% of the time. The SIT 185 message provides the probability that each of two provided Doppler positions (i.e., an “A” position and a “B” position) correspond to the real position.

5–12

The “OTHER INFORMATION” section of the SIT 185 message provides further information about position data that is “SUSPECT” (e.g., due to a satellite footprint check or a satellite manoeuvre). Note: More detailed information on SIT 185 message content can be obtained by contacting your supporting MCC, or by reviewing document C/S A.002 on the Cospas- Sarsat website (www.cospas-sarsat.int). 5.5 Paragraph 5: Other Information Other information obtained by the MCC that may be valuable to SAR authorities. This information includes: a) Doppler position reliability if suspect due to less than ideal satellite pass geometry processing parameters; b) Doppler position reliability if suspect due to a satellite manoeuvre (when an error greater than ten (10) kilometres is suspected); c) Doppler or DOA position reliability if suspect due to failure of satellite footprint check; d) determination of an image (incorrect) position using a footprint check prior to Doppler location ambiguity resolution; and e) if the beacon message is invalid then the warning is given that the data decoded from the beacon message is not reliable. If Doppler position is provided without a warning that its reliability is suspect, then it is expected that the Doppler position is accurate within five (5) kilometres. Note that a nominal Doppler solution (i.e., one generated when satellite pass geometry is ideal, as specified in document C/S T.005), is required to be accurate within five (5) kilometres in 95% of cases. The MCC may also provide additional information in this section; for example, the identity of the LUT that processed the beacon message or beacon database registry information. 5.5.1 Detection Frequency The frequency is the actual frequency of the beacon transmission as determined by the LUT. As of 2025, Cospas-Sarsat distress FGBs were using 406.025 MHz, 406.028 MHz, 406.031 MHz, 406.037 MHz, 406.040 MHz and 406.076 MHz channels (an updated list of frequencies in use can be found at Annex H of document C/S T.012). If the actual frequency is not available for an FGB, then the value “406 MHZ” is provided. The center frequency value “406.05 MHZ” is reported for SGB alerts without DOA position. Knowledge of the individual frequencies may assist Responsible Agencies when tasking aircraft with a 406 MHz direction finding capability.

5–13

5.5.2 Other Encoded Information Other information may be decoded and provided from the 406 MHz message, including: • Cospas-Sarsat beacon type approval certificate (“TAC”) number from which the beacon model and manufacturer can be ascertained, • the precision of the GNSS position. When GNSS position data is present, its uncertainty, which is the maximum possible difference between the GNSS position processed by the beacon and the GNSS position transmitted in the SIT 185 Message, is provided in the following format in Paragraph 5, where the degree of uncertainty is provided in Table 5.2. “GNSS POSITION UNCERTAINTY PLUS-MINUS [X MINUTES/SECONDS] OF LATITUDE AND LONGITUDE.” Table 5.2: GNSS Position Uncertainty Uncertainty Comments 2 MINUTES FGB User location protocol 2 SECONDS ELT(DT), RLS, standard and national location protocol, maximum resolution (FGB only) 15 MINUTES ELT(DT), RLS protocol, minimum resolution (FGB only) 30 MINUTES FGB Standard location protocol, minimum resolution* 4 MINUTES FGB National location protocol, minimum resolution* 10 METRES SGBs

• For standard and national location protocols, the reported degree of uncertainty assumes that the associated FGB is coded with an older methodology, in which the last bit available to report a coarse GNSS position may not be used. The actual uncertainty is one fourth the reported uncertainty (i.e., 7 minutes 30 seconds for standard location protocol and one (1) minute for national location protocol, as noted in section 2.6), if it is known that the associated beacon is coded with a newer methodology in which all bits available to report a coarse GNSS position are used. Based on the Type Approval Certificate (TAC) number associated with the beacon model, as provided in Paragraph 5, further information about the uncertainty of a coarse GNSS position may be available on the Cospas-Sarsat website link for “Type Approval Certificate Numbers”. If an SGB has no GNSS position capability, “BEACON DOES NOT HAVE GNSS POSITION CAPABILITY” is indicated in the alert message. For SGBs, other information is provided from the beacon message, if available: • “ELAPSED TIME SINCE ACTIVATION: [nn] HOURS”, where the time since activation is truncated, and

5–14

• “REMAINING BATTERY CAPACITY: BETWEEN [nn] AND [nnn] PERCENT”. If information on beacon characteristics is available for the TAC number encoded in the beacon message, then this statement is provided: “BEACON CHARACTERISTICS PER TAC DATABASE PROVIDED IN A SEPARATE MESSAGE”. The corresponding information on beacon characteristics is provided in a SIT 985 message. 5.6 Paragraph 6: Remarks Additional information may be provided at the discretion of the originating MCC in this paragraph and may include value-added information from the MCC operator. For ship security alerts, advice is included that the alert will need to be processed in accordance with relevant security procedures. In alert messages for an ELT(DT), the following is included in the alert: “THIS DISTRESS TRACKING MESSAGE IS BEING SENT TO APPROPRIATE SAR AUTHORITIES” and “PROCESS THIS ALERT ACCORDING TO RELEVANT REQUIREMENTS”. Administrations should follow defined national SAR procedures for responding to the activation of an ELT(DT). As the alert is likely emanating from an aircraft still in flight, “DISTRESS TRACKING” alert messages should be sent to an Aeronautical RCC (ARCC) which should rapidly liaise with relevant ATSU(s) and airline operator(s) as specified in dedicated annexes to the ICAO Convention, IAMSAR Manual (ICAO document DOC 9731), and GADSS documentation. The following is included in the alert message for Return Link Service (RLS) beacons: • “THIS BEACON HAS [RLS-ID] RETURN LINK CAPABILITY where RLS-ID identifies the RLS provider (e.g., GALILEO or GLONASS) when available. The alert message for a RLS beacon also indicates: • RLM TYPE-[X] [RECEIVED/CAPABLE] ([AUTO/MANUAL] ACKNOWLEDGEMENT) where:

[X] is replaced with “1” or “2”. TYPE-1 provides “AUTOMATIC” acknowledgement and TYPE-2 provides “MANUAL” acknowledgment; only TYPE-1 beacons are currently authorized.

“[RECEIVED/CAPABLE]” is replaced with “RECEIVED” or “CAPABLE”,

“[AUTO/MANUAL]” is replaced with “AUTOMATIC” or “MANUAL”.

5–15

5.7 End of Message This text is added to the message to give an unambiguous indication to the message recipient that there is no further information.

• END OF SECTION 5 -

6–1

EXAMPLES OF BEACON INCIDENTS This section contains examples of beacon incidents and the distress alerts sent to Distress authorities. Some examples are based on real-world incidents; others have been modified or created to demonstrate specific aspects of beacon processing. All examples are for FGBs, except when it is explicitly noted that an example is for an SGB. Space and Ground Segment situations described in these examples do not reflect the current status and should be used for training purpose only. 6.1 An Unlocated Detection to a Position Confirmed Update This incident shows how information relating to an EPIRB with the Hex ID: BEEE4634B00028D is presented to a SAR Service as four consecutive SIT 185 messages. The four SIT 185 messages demonstrate a common sequence of messages received by a SAR Service. Figure 6.1 provides a graphical depiction of the message sequence. Figure 6.1: Sequence of Four SIT 185 Messages Sent to a SAR Service in Example 6.1

6–2

6.1.1 An Initial (Unlocated) Alert

1. DISTRESS COSPAS-SARSAT INITIAL ALERT (UNLOCATED)
2. MSG NO 00189 AUMCC REF BEEE4634B00028D
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER - EPIRB (NON FLOAT-FREE) SERIAL NO 101676 HEX ID BEEE4634B00028D COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE NIL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 15 MAR 23 1230 UTC BY MEOSAR ALERT LAST DETECTED AT 15 MAR 23 1230 UTC GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A – NIL DOPPLER B - NIL
5. OTHER INFORMATION DETECTION FREQUENCY 406.0280 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

The type of alert is listed in Paragraph 1. This example is an initial alert. An initial alert that does not have a position is often called an “unlocated” alert. 2. Paragraph 2 lists the message number of 00189 and an MCC beacon reference. The message number allows all messages between an MCC and a SAR Service to be uniquely identified. A SAR Service can use the message number to check that there are no missing messages. The MCC beacon reference is used to identify the beacon incident; all alerts for this beacon incident will use the same beacon reference. The Australian MCC uses the Hex ID of the beacon as the reference, other MCCs may use a different reference system. 3. The initial alert contains the beacon Hex ID in Paragraph 3. In the example, the Hex ID also appears in Paragraph 2 as the AUMCC reference. 4. Paragraph 4 contains the detection time of the first MEOSAR burst of “15 MAR 23 1230 UTC”. The next data line contains the detection time of the last MEOSAR burst used in this alert. In this example, the times of the first and last burst are the same, indicating that this is a single burst solution.

6–3

Paragraph 3 lists the country of registration. For this example, the country of registration is Australia. 6. This alert was an unlocated detection, and Paragraph 4 lists no positions. The positions are all shown as “NIL” to indicate that no position information is available. If the value for a specific position is “NIL”, then the associated data line may be omitted from the alert message. As this is an unlocated detection, the alert is sent to the SAR Service associated with country of registration for the beacon. In this example, the alert is sent to the Australian JRCC as the beacon has Australia as the country of registration. 7. Paragraph 3 contains information about the beacon. In this case, the serial number of the EPIRB is “101676”. The serial number of the EPIRB can be used to look up the beacon in the Australian beacon registry. If the beacon is registered, the contact details may allow the Australian JRCC to commence responding to this initial detection.

6–4

6.1.2 An Initial Alert with a MEOSAR Location

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 00190 AUMCC REF BEEE4634B00028D
3. BEACON INFORMATION BEACON TYPE SERIAL USER - EPIRB (NON FLOAT-FREE) SERIAL NO 101676 HEX ID BEEE4634B00028D COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 15 MAR 23 1230 UTC BY MEOSAR ALERT LAST DETECTED AT 15 MAR 16 1237 UTC DOA - 17 47.2 S 146 04.5 E ESTIMATED ERROR 005 NMS
5. OTHER INFORMATION DETECTION FREQUENCY 406.0280 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

This is an initial alert with a location. The location shown in Paragraph 4 is a DOA (Difference of Arrival) or MEOSAR location. The location is shown with an estimated error, and, in this example, the beacon will be located within five (5) nautical miles of the location, 95% of the time. 2. The DOA Altitude value is not provided until further notice and is omitted in this sample message. 3. The DOA Position Conflict Alert message below is sent because the distance between the DOA position which was independently processed by the Cospas-Sarsat System, and the GNSS position which was processed by the GNSS receiver associated with the FGB ELT(DT), is at least 20 km. 4. Fields in paragraphs 3 and 4 with a “NIL” value have been omitted. 5. The reference in Paragraph 2 (the Hex ID of the beacon) is used by the SAR Service to associate this alert to the same beacon incident as the alert shown in section 6.1.1. 6. Paragraph 4 contains the detection time of the first burst, “15 MAR 23 1230 UTC” and the detection time of the last burst, “15 MAR 23 1237 UTC”. As the two times are different, this a multi-burst solution.

6–5

6.1.3 A Position Confirmed Alert

1. DISTRESS COSPAS-SARSAT POSITION UPDATE ALERT
2. MSG NO 00191 AUMCC REF BEEE4634B00028D
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER - EPIRB (NON FLOAT-FREE) SERIAL NO 101676 HEX ID BEEE4634B00028D COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 15 MAR 23 1248 UTC BY MEOSAR ALERT LAST DETECTED AT 15 MAR 23 1248 UTC MCC REFERENCE - 17 47.5 S 146 06.2 E DOA - 17 47.6 S 146 07.4 E ESTIMATED ERROR 005 NMS
5. OTHER INFORMATION DETECTION FREQUENCY 406.0280 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

A position confirmed alert (in this case, with title “Position Update Alert”) is sent when two independent locations match, as described in section 4.1.3. In this example, the DOA (MEOSAR) location shown in Paragraph 4 has matched the location in the previous alert in section 6.1.2. See the description of “Confirmation” in section 4.1.3. 2. The MCC reference position shown in Paragraph 4 is determined based on a weighting factor assigned to each previous DOA location. The AUMCC merges DOA locations to produce an MCC reference position. Other MCCs may use other methods to determine the MCC reference position.

6–6

6.1.4 A Position Confirmed Update Alert

1. DISTRESS COSPAS-SARSAT POSITION UPDATE ALERT
2. MSG NO 00194 AUMCC REF BEEE4634B00028D
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER - EPIRB (NON FLOAT-FREE) SERIAL NO 101676 HEX ID BEEE4634B00028D COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 15 MAR 23 1301 UTC BY MEOSAR ALERT LAST DETECTED AT 15 MAR 23 1301 UTC MCC REFERENCE - 17 47.6 S 146 05.3 E DOA - 17 47.9 S 146 04.5 E ESTIMATED ERROR 002 NMS
5. OTHER INFORMATION DETECTION FREQUENCY 406.0280 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

If the SAR service is configured to receive ongoing updates after position confirmation, the MCC will send an update to the MCC reference position in a number of conditions; e.g., if a solution with matching DOA position is processed with a data time at least 15 minutes after the most recent data time of previous message with DOA position, or if a Doppler solution is processed for a new beacon event. 2. In this example, the updated MCC reference position was computed based on a weighting factor assigned to each previous DOA position.

6–7

6.2 From Unlocated Alert to Position Confirmation The following incident has similar SIT 185 messages to those in section 6.1 but demonstrates detections from the GEOSAR and LEOSAR systems. The incident shows the SIT 185 messages sent to a SAR Service for an EPIRB with Hex ID BEEE43FCF8001AD. The three SIT 185 messages for this incident are depicted in Figure 6.2. 6.2.1 A GEOSAR Unlocated Alert

1. DISTRESS COSPAS-SARSAT INITIAL ALERT (UNLOCATED)
2. MSG NO 12301 AUMCC REF BEEE43FCF8001AD
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER - EPIRB (NON FLOAT FREE) SERIAL NO 0065342 HEX ID BEEE43FCF8001AD COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 27 APR 24 1557 UTC BY GEOSAR INSAT-3D GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A - NIL DOPPLER B - NIL
5. OTHER INFORMATION LUT ID 4191 BANGALORE GEOLUT, INDIA DETECTION FREQUENCY 406.0286 MHZ TAC 0107 BEACON MODEL - ACR, USA RLB-32
6. REMARKS NIL END OF MESSAGE Figure 6.2: Sequence of Three Beacon Messages Sent in Example 6.2

6–8

Notes: 1. Paragraph 4 states that the detection was by satellite INSAT-3D, a geostationary satellite. The beacon is expected to be located within the footprint of the INSAT-3D satellite which is centred at (0° N, 082° E). See Figure 6.3 below. 2. No position information is shown in Paragraph 4, since this is an unlocated initial detection of the beacon. Figure 6.3: Footprint of the GEOSAR INSAT-3D Satellite In the Figure 6.3 above, the outline of the footprint is shown by the yellow line. The position of the INSAT-3D satellite is shown by the yellow diamond in the centre of the footprint.

6–9

6.2.2 A LEOSAR Initial Alert

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 12307 AUMCC REF BEEE43FCF8001AD
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER LOCATION - EPIRB (NON FLOAT FREE) SERIAL NO 0065342 HEX ID BEEE43FCF8001AD COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 27 APR 23 1653 UTC BY LEOSAR SARSAT 12 GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A - 43 04.04 S 147 15.75 E PROB 83 PERCENT DOPPLER B - 51 45.19 S 167 48.58 W PROB 17 PERCENT
5. OTHER INFORMATION THE B POSITION IS LIKELY TO BE AN IMAGE POSITION DETECTION FREQUENCY 406.0277 MHZ TAC 0107 BEACON MODEL - ACR, USA RLB-32 LUT ID 6011
6. REMARKS NIL END OF MESSAGE Notes:

Paragraph 4 indicates that the detection was made by LEOSAR satellite Sarsat-12, a when it passed by the beacon. Paragraph 5 reports that the detection was further received by the LEOLUT 6011 in Cape Town, South Africa when Sarsat-12 and this LEOLUT were in mutual visibility. 2. Paragraph 5 indicates that the B position is the likely image position. Figure 6.4 shows the Doppler locations on a map. The B position is outside the footprint of INSAT-3D, the geostationary satellite that provided the first detection. Although image determination provides a strong indicator that the A position is the “real” position, image determination is not used by Cospas-Sarsat to provide confirmation of a position.

6–10

Figure 6.4: LEOSAR Initial Alert The yellow line is the track (path) of the LEOSAR satellite Sarsat-12. The orange outline is the footprint of Sarsat-12 at the TCA (Time of Closest Approach) of the beacon. The two Doppler locations generated by this pass are shown. The location of the LEOLUT 6011 in Cape Town, South Africa is also shown.

6–11

6.2.3 A LEOSAR Position Confirmed Alert

1. DISTRESS COSPAS-SARSAT POSITION UPDATE ALERT
2. MSG NO 63523 AUMCC REF BEEE43FCF8001AD
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER LOCATION - EPIRB (NON FLOAT FREE) SERIAL NO 0065342 HEX ID BEEE43FCF8001AD COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA HOMING SIGNAL 121.5 ACTIVATION TYPE MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 27 APR 23 1716 UTC BY LEOSAR SARSAT 10 MCC REFERENCE - 43 03.25 S 147 15.96 E DOPPLER A - 43 02.89 S 147 15.91 E
5. OTHER INFORMATION DETECTION FREQUENCY 406.0276 MHZ TAC 0107 BEACON MODEL - ACR, USA RLB-32 LEOLUT 6011
6. REMARKS NIL END OF MESSAGE Notes:

The position has been confirmed using data from a second LEOSAR detection (satellite Sarsat-10 shown in Paragraph 4) that matches a Doppler position from the previous initial alert. See the description of “Confirmation” in section 4.1.3. 2. The matching Doppler A position is provided along with the MCC reference position in Paragraph 4. In this example, the MCC reference position computed by the MCC from the initial and subsequent alerts is biased to the location that is more likely to be accurate (as the magnitude of the error ellipse is less). The Doppler A position information provides for a means to ensure that the MCC processing is normal and enables the SAR Service to reference the individual (un-merged) position in planning its SAR response. 3. The A position of the Sarsat-10 pass matches the A position of the initial alert from Sarsat-12 which results in an MCC reference position being computed (see Figure 6.5).

6–12

Figure 6.5: Confirmation of Position Using a LEOSAR Alert In the Figure 6.5 above, the yellow line is the track of LEOSAR satellite Sarsat-10. The orange outline is the footprint of Sarsat-10 at the TCA for this beacon. The two Doppler locations generated by this pass are shown. The Doppler A position for this detection matches the Doppler A position from the previous detection (see Figure 6.4) and confirms the location.

6–13

6.3 A Position Confirmed Alert as the First Alert In this example, the first alert received by the SAR Service is a position confirmed alert. The presence of a position in the field titled “MCC REFERENCE” indicates that position is confirmed, based on the matching of two independent locations, as described in section 4.1.3 above. 6.3.1 A Position Confirmed Alert

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 00463 AUMCC REF 3EEC7B9076FFBFF
3. BEACON MESSAGE INFORMATION BEACON TYPE STANDARD LOCATION – EPIRB SERIAL NO 2107 HEX ID 3EEC7B9076FFBFF COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA HOMING SIGNAL 121.5 GNSS POSITION PROVIDED BY INTERNAL DEVICE
4. ALERT POSITION INFORMATION DETECTED AT 03 APR 23 1124 UTC BY MEOSAR ALERT LAST DETECTED AT 03 APR 23 1124 UTC GNSS - 25 40.07S 113 39.00E UPDATE TIME WITHIN 4 HOURS OF DETECTION TIME MCC REFERENCE - 25 39.5 S 113 37.3 E DOA - 25 39.5 S 113 37.3 E ESTIMATED ERROR 004 NMS
5. OTHER INFORMATION DETECTION FREQUENCY 406.0402 MHZ GNSS POSITION UNCERTAINTY PLUS-MINUS 2 SECONDS OF LATITUDE AND LONGITUDE
6. REMARKS NIL END OF MESSAGE Notes:

Paragraph 4 shows that this alert has a DOA position and a GNSS position. 2. As the DOA position and GNSS position match (the two positions are approximately three (3) kilometres apart and so are within the twenty-kilometre matching criterion) and are independent, the position is confirmed. 3. The AUMCC does not merge a DOA position and a GNSS position to produce an MCC reference position. Instead, the AUMCC uses the DOA position as the MCC reference position. Other MCCs may merge the DOA and GNSS position to produce the MCC reference position. 4. Paragraph 5 provides the uncertainty of the GNSS position as two (2) seconds of latitude and longitude, about 60 metres at the equator. A GNSS position with two (2) seconds of uncertainty is generally the most accurate position for a beacon, provided that the GNSS position has been updated recently or the beacon is not moving.

6–14

6.4 A MEOSAR Alert Confirmed by a LEOSAR Alert The beacon with the Hex ID: C809C70A34D34D1 is first detected with a MEOSAR location that is later confirmed with LEOSAR location data. Figure 6.6 depicts the two messages. Figure 6.6: The Two SIT 185 Messages in Example 6.4 6.4.1 An Initial Alert from the MEOSAR System

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 05714 AUMCC REF C809C70A34D34D1
3. BEACON MESSAGE INFORMATION BEACON TYPE USER - EPIRB USER MMSI ALL 9 DIGITS 576774000 HEX ID C809C70A34D34D1 COUNTRY OF BEACON REGISTRATION 576/VANUATU BEACON NUMBER ON AIRCRAFT OR VESSEL 0 HOMING SIGNAL 121.5 ACTIVATION TYPE AUTOMATIC OR MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 17 OCT 23 0637 UTC BY MEOSAR ALERT LAST DETECTED AT 17 OCT 23 0637 UTC DOA – 22 53.34 S 170 15.06 E ESTIMATED ERROR UNKNOWN
5. OTHER INFORMATION DETECTION FREQUENCY 406.035 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

Paragraph 4 indicates that this is a MEOSAR alert and provides the initial position. The estimated error is shown as “UNKNOWN” because the reporting MEOLUT is not commissioned to meet MEOSAR IOC requirements for DOA position accuracy and the reliability of the estimated error. 2. The MMSI for the vessel is formed by using the country code (576) and the beacon information of 774000. The MMSI is therefore 576774000.

6–15

6.4.2 A Position Confirmed Alert using LEOSAR Data A later LEOSAR detection provides further position information that is used to confirm the position for the beacon with Hex ID: C809C70A34D34D1, as shown below. See the description of “Confirmation” in section 4.1.3.

1. DISTRESS COSPAS-SARSAT POSITION UPDATE ALERT
2. MSG NO 05717 AUMCC REF C809C70A34D34D1
3. BEACON MESSAGE INFORMATION BEACON TYPE USER - EPIRB USER MMSI ALL 9 DIGITS 576774000 HEX ID C809C70A34D34D1 COUNTRY OF BEACON REGISTRATION 576/VANUATU BEACON NUMBER ON AIRCRAFT OR VESSEL 0 HOMING SIGNAL 121.5 ACTIVATION TYPE AUTOMATIC OR MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 17 OCT 23 0647 UTC BY LEOSAR SARSAT 10 MCC REFERENCE - 22 53.34 S 170 15.06 E DOPPLER A - 22 50.15 S 170 13.76 E
5. OTHER INFORMATION DETECTION FREQUENCY 406.0370 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

The MCC reference position is identical to the previously received DOA position as the Doppler location matches the DOA position. 2. The AUMCC has used the previous DOA location as the MCC reference position and has not merged the DOA location with the matching Doppler location. Other MCCs may merge the matching DOA and Doppler location to produce the MCC reference position or use the Doppler location as the MCC reference position.

6–16

6.5 A Position Conflict Alert The following example with an ELT with Hex ID 2DC753D464FFBFF shows an incident where two positions generated do not match and a conflict alert is sent to the SAR Service. The example is based on a real-world incident but amended for presentation. (The actual format of SIT 185 messages sent by the USMCC differs somewhat from those shown in these examples. Note that the USMCC sends national formatted messages to its national SAR Services rather than SIT 185 messages.) 6.5.1 A GEOSAR GNSS Position Alert The initial GEOSAR detection provides GNSS position information for the beacon with Hex ID 2DC753D464FFBFF:

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 72554 USMCC REF 42321
3. BEACON MESSAGE INFORMATION BEACON TYPE STANDARD LOCATION PROTOCOL - ELT AIRCRAFT 24-BIT ADDRESS A9EA32 ASSIGNED TO USA HEX ID 2DC753D464FFBFF COUNTRY OF BEACON REGISTRATION 366/USA BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 ACTIVATION TYPE NIL GNSS POSITION PROVIDED BY EXTERNAL DEVICE EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 28 APR 23 1702 UTC BY GEOSAR GOES 17 GNSS - 33 31.27 N 083 56.93 W UPDATE TIME WITHIN 4 HOURS OF DETECTION TIME
5. OTHER INFORMATION LUT ID 5123 DETECTION FREQUENCY 406.0248 MHZ GNSS POSITION UNCERTAINTY PLUS-MINUS 2 SECONDS OF LATITUDE AND LONGITUDE
6. REMARKS NIL END OF MESSAGE Notes:

Paragraph 4 shows the detection was made by the GOES-17 geostationary satellite. 2. Paragraph 4 provides the GNSS position detected by the GOES-17 satellite. The GNSS position is within the USMCC service area. 3. Paragraph 3 indicates that the GNSS position was provided by an external device and no further updates to the GNSS position will be possible under normal activation. 4. Paragraph 5 provides the uncertainty of the GNSS position.

6–17

Some message fields are “NIL” in Paragraph 3. Message fields containing “NIL” in Paragraph 4 have been omitted. 6. The "AIRCRAFT 24-BIT ADDRESS A9EA32" (in paragraph 3 of the message) is equivalent to the bit sequence “101010011110101000110010”. As noted in Figure 6.7 below, the ICAO 24-bit allocation for the USA is “1010”. Since the first four bits of the address match that value, paragraph 3 indicates that this address is assigned to the USA. The remaining 20 bits are used to code the individual US aircraft 7. SIT 185 messages sent by the USMCC contain a 5-digit alert site number associated with the beacon activation (e.g., 42321) as the “USMCC REF” in Paragraph 2. This number is unique to a beacon activation and if the same beacon is activated again at a different time, the 5-digit alert site number will be different. Figure 6.7: ICAO 24-bit Addressing

6–18

Figure 6.7 above, contains an extract from the ICAO document [Annex 10 Vol III] concerning 24-bit addressing. The table shows that the allocation of addresses uses the four-bit sequence 1010 to indicate a US aircraft. Figure 6.8: GEOSAR GNSS Position Alert In the Figure 6.8 above, the footprint of the GEOSAR satellite GOES-17 is shown in yellow and the location of the GOES-17 is shown by the yellow diamond. The location of the GNSS position provided in the beacon message is shown by the green triangle in the USA.

6–19

6.5.2 A Position Conflict Alert from a LEOSAR Position The alert in this example is a LEOSAR detection that has two Doppler locations and a GNSS position. Since neither Doppler location matches the GNSS position, a position conflict alert is generated.

1. DISTRESS COSPAS-SARSAT POSITION CONFLICT ALERT
2. MSG NO 72555 USMCC REF 42321
3. BEACON MESSAGE INFORMATION BEACON TYPE STANDARD LOCATION PROTOCOL – ELT AIRCRAFT 24-BIT ADDRESS A9EA32 ASSIGNED TO USA HEX ID 2DC753D464FFBFF COUNTRY OF BEACON REGISTRATION 366/USA HOMING SIGNAL 121.5 GNSS POSITION PROVIDED BY EXTERNAL DEVICE
4. ALERT POSITION INFORMATION DETECTED AT 28 APR 23 1702 UTC BY LEOSAR SARSAT 10 GNSS - 33 31.27 N 083 56.93 W UPDATE TIME WITHIN 4 HOURS OF DETECTION TIME DOPPLER A - 33 09.82 N 085 19.92 W PROB 56 PERCENT DOPPLER B - 44 41.41 N 144 00.65 W PROB 44 PERCENT
5. OTHER INFORMATION RELIABILITY OF DOPPLER POSITION DATA - SUSPECT DUE TO TECHNICAL PARAMETERS POSITION CONFLICT BASED ON DISTANCE SEPARATION AT LEAST 20 KM DETECTION FREQUENCY 406.0247 MHZ GNSS POSITION UNCERTAINTY PLUS-MINUS 2 SECONDS OF LATITUDE AND LONGITUDE
6. REMARKS NIL END OF MESSAGE Notes:

The two Doppler positions shown in Paragraph 4 do not match the GNSS position. The closer Doppler, the A position (33° 10’ N, 085° 19’ W) is some 285 kilometres from the GNSS position (33° 31’ N, 083° 57’ W). As the positions do not match, a position conflict alert is sent to the RCC. 2. In Paragraph 5, the Doppler position has been assessed as suspect due to technical parameters. The satellite pass geometry (Cross Track Angle 23.7 degrees) is such that the Doppler locations were near the edge of the satellite footprint and were assessed as suspect. See Figure 6.9. As the Doppler positions are suspect, the GNSS position is more likely to be the real beacon position than the Doppler positions, but the matching of position data from independent sources is required to determine the real position of the beacon.

6–20

Figure 6.9: LEOSAR Position Conflict Alert In the Figure 6.9 above, the footprint of LEOSAR satellite Sarsat-10 at the TCA is shown in orange, the yellow line is the track (path) of the satellite. The two Doppler locations generated for this beacon detection are shown on the map. A position conflict alert is generated as neither Doppler location is within the matching distance of 20 kilometres of the GNSS position.

6–21

6.6 A Notification of Country of Registration Alert 6.6.1 An NOCR Alert An NOCR alert is sent by an MCC to the country of registration for a beacon located inside the service area of the MCC. In this example, the beacon with the Hex ID C809C70A34D34D1 which is a Vanuatu EPIRB has locations in the Brazilian MCC’s service area. The Brazilian MCC would send the NOCR to the Vanuatu SAR Service via the MCC Network.

1. DISTRESS COSPAS-SARSAT NOTIFICATION OF COUNTRY OF BEACON REGISTRATION ALERT
2. MSG NO 05714 AUMCC REF C809C70A34D34D1
3. BEACON MESSAGE INFORMATION BEACON TYPE USER - EPIRB USER MMSI ALL 9 DIGITS 576774000 HEX ID C809C70A34D34D1 COUNTRY OF BEACON REGISTRATION 576/VANUATU BEACON NUMBER ON AIRCRAFT OR VESSEL 0 HOMING SIGNAL 121.5 ACTIVATION TYPE AUTOMATIC OR MANUAL
4. ALERT POSITION INFORMATION DETECTED AT 17 MAY 23 0637 UTC BY LEOSAR SARSAT 10 DOPPLER A - 18 33.54 S 062 15.06 W PROB 60 PERCENT DOPPLER B - 22 53.34 S 043 21.60 W PROB 40 PERCENT
5. OTHER INFORMATION LUT ID 7101 BRAZILIA, BRAZIL DETECTION FREQUENCY 406.0370 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

A Notification of Country of Registration (NOCR) alert message is sent to the country of beacon registration by an MCC that has an alert with a position inside its service area when the MCC has no other location within the SAR region of the country of beacon registration. The NOCR alert message is intended to alert the SAR Service responsible for the country code when the SAR Service would not otherwise be sent a located alert for the beacon. 2. In the alert message above the Brazilian MCC (BRMCC), in whose service area the beacon was located, transmitted a NOCR alert message to the Australian MCC (AUMCC) via the USA MCC (USMCC) for forwarding to the Vanuatu authorities. As Vanuatu is serviced by the Noumea RCC in New Caledonia, the AUMCC has forwarded the NOCR alert to Noumea RCC for delivery to the Vanuatu SAR Service. 3. A graphical representation of the NOCR alert message is provided in Figure 6.10.

6–22

Figure 6.10: Graphical Representation of the NOCR Alert Message In the Figure 6.10 above, the yellow line is the track of LEOSAR satellite Sarsat- 10. The footprint of Sarsat-10 at the TCA is shown in orange. As the beacon has a country of registration of Vanuatu and has location data in the Brazilian MCC service area, the Brazilian MCC sends a NOCR via the MCC network. In this case, the NOCR would be sent via the United Status MCC, the Australian MCC and the New Caledonian SPOC to the Vanuatu SPOC.

6–23

6.7 An Unresolved Doppler Position Match Alert 6.7.1 A LEOSAR Unresolved Doppler Position Match Alert An unresolved Doppler position match alert is sent when two independent LEOSAR detections match both possible Doppler locations prior to position confirmation. In this example, the first detection is not shown. The second detection generated the unresolved Doppler position match alert.

1. DISTRESS COSPAS-SARSAT UNRESOLVED DOPPLER POSITION MATCH ALERT
2. MSG NO 55408 AUMCC REF CDC9D64D41934D1
3. BEACON MESSAGE INFORMATION BEACON TYPE USER LOCATION - EPIRB USER MMSI ALL 9 DIGITS 622120320 HEX ID CDC9D64D41934D1 COUNTRY OF BEACON REGISTRATION 622/EGYPT BEACON NUMBER ON AIRCRAFT OR VESSEL 0 HOMING SIGNAL 121.5 ACTIVATION TYPE AUTOMATIC OR MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 17 MAY 23 0900 UTC BY LEOSAR SARSAT 11 GNSS - NIL MCC REFERENCE - NIL DOA - NIL DOPPLER A - 36 34.74 N 000 22.26 W PROB 99 PERCENT DOPPLER B - 31 03.12 N 026 24.30 E PROB 01 PERCENT
5. OTHER INFORMATION WARNING: AMBIGUITY IS NOT RESOLVED LUT ID 6011 CAPE TOWN, SOUTH AFRICA DETECTION FREQUENCY 406.0368 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

When both pairs of Doppler positions meet the match criterion prior to ambiguity resolution for different satellite passes on similar orbital paths as shown in Figure 6.11, an unresolved Doppler position match alert will be generated. (Note that in previous example from 2011, the match criterion was 50 kilometres. The match criterion has since been changed to 20 kilometres, also, the figure below is not to scale.) 2. For the example above the following two pairs of Doppler locations were received: Satellite Sarsat-10 TCA 0704 UTC, 17 May 2023, A. 36° 18.1’ N - 000° 01.4’ E B. 31° 05.0’ N - 025° 55.1’ E Satellite Sarsat-11 TCA 0900 UTC, 17 May 2023, A. 36° 34.7’ N - 000° 22.3’ W B. 31° 03.1’ N - 026° 24.3’ E

6–24

Both the A pair and B pair locations from the two satellites were within 20 kilometres and this is depicted in Figure 6.8. As a consequence, ambiguity in position cannot be resolved and an unresolved Doppler position match alert is transmitted. 4. As a consequence, a warning will be inserted in the alert message in Paragraph 5 indicating that ambiguity has not been resolved. 5. Although ambiguity is unresolved (i.e., position is unconfirmed), the new “A” position is likely the true position based on its probability (99 percent). Figure 6.11: Unresolved Doppler Position Match In the Figure 6.11 above, the red line is the track of LEOSAR satellite Sarsat-10. The purple line is the track of LEOSAR satellite Sarsat-11. The two Doppler locations generated by the Sarsat-10 pass are shown as the two red triangles. The two Doppler locations generated by the Sarsat-11 pass are shown as the two purple triangles. As both sets of Doppler positions match, neither location is confirmed.

6–25

6.8 ELT(DT) Alerts An ELT(DT) alert is sent after an ELT(DT) has been activated: manually by the crew, automatically by the beacon when a probable crash has been detected (G-switch), or automatically by the avionics when an aeroplane is in a distress condition. 6.8.1 An FGB ELT(DT) Alert The DOA Position Conflict Alert message below is sent because the distance between the DOA position which was independently processed by the Cospas-Sarsat System and the GNSS position which was processed by the GNSS receiver associated with the FGB ELT(DT), is at least 20 km away.

1. DISTRESS TRACKING COSPAS-SARSAT DOA POSITION CONFLICT ALERT
2. MSG NO 21013 CMCC REF 1D1200F03BBFDFF
3. BEACON MESSAGE INFORMATION BEACON TYPE ELT DISTRESS TRACKING AIRCRAFT 24 BIT ADDRESS 01E077 ASSIGNED TO G BRITAIN AIRCRAFT OPERATOR DESIGNATOR MMB HEX ID 1D1200F03BBFDFF COUNTRY OF BEACON REGISTRATION 232/G BRITAIN ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY EXTERNAL DEVICE
4. ALERT POSITION INFORMATION DETECTED AT 04 AUG 23 101501 UTC BY MEOSAR ALERT LAST DETECTED AT 04 AUG 23 101501 UTC GNSS - 61 54.40 N 045 37.53 W UPDATE TIME WITHIN 2 – 60 SECONDS OF DETECTION TIME ALTITUDE OF GNSS LOCATION BETWEEN 1600 AND 2200 METRES (BETWEEN 5200 AND 7200 FEET) DOA - 62 00.1 N 046 06.2 W
5. OTHER INFORMATION GNSS POSITION UNCERTAINTY PLUS-MINUS 2 SECONDS OF LATITUDE AND LONGITUDE DETECTION FREQUENCY 406.0400 MHZ POSITION CONFLICT BASED ON DISTANCE SEPARATION OF AT LEAST 20 KM ELT(DT) POSITION DOES NOT REFERENCE ANY PREVIOUS POSITION
6. REMARKS THIS DISTRESS TRACKING MESSAGE IS BEING SENT TO APPROPRIATE SAR AUTHORITIES PROCESS THIS ALERT ACCORDING TO RELEVANT REQUIREMENTS END OF MESSAGE

6–26

Notes: 1. Paragraph 1: The beacon message type is “DISTRESS TRACKING”. 2. Paragraph 2: The beacon type is “ELT”, and the beacon subtype is “DISTRESS TRACKING” for ELT(DT). The beacon is an FGB, since the beacon type does not indicate “SGB”. 3. Paragraph 3 provides the ICAO 24-bit address and the aircraft flag decoded from this ICAO 24-bit address, 4. Paragraph 3 also provides the 3-Letter Designator (3LD) of the airline operator (as encoded in the FGB ELT(DT) rotating field) from which the airline can be identified per ICAO document DOC 8585, 5. Paragraph 4: For an FGB ELT(DT), the altitude of the GNSS position is provided within a predetermined range of altitude values, in metres (and feet), 6. Paragraph 6: See section 5.6 above for more information about “relevant requirements”.

6–27

6.8.2 An SGB ELT(DT) Alert The DOA Position Match Alert message below is sent because the distance between the DOA position that was independently processed by the Cospas-Sarsat System computed by the MEOLUT and the GNSS position that was processed by the GNSS receiver associated with the SGB ELT(DT) is less than 20 km.

1. DISTRESS TRACKING COSPAS-SARSAT DOA POSITION MATCH ALERT
2. MSG NO 00192 AUMCC REF B274FA041FD4710
3. BEACON MESSAGE INFORMATION BEACON TYPE SGB – ELT DISTRESS TRACKING AIRCRAFT 24 BIT ADDRESS 7100CE ASSIGNED TO SAUDI ARABIA AIRCRAFT OPERATOR DESIGNATOR SVA TAC 16001 SERIAL NO 509 HEX ID B274FA041FD4 7100CEA3F00 COUNTRY OF BEACON REGISTRATION 403/SAUDI ACTIVATION TYPE AUTOMATIC BY BEACON (G-SWITCH/PROBABLE CRASH)
4. ALERT POSITION INFORMATION DETECTED AT 03 MAY 23 085310 UTC BY MEOSAR ALERT LAST DETECTED AT 03 MAY 23 085310 UTC GNSS - 02 24.40 N 046 04.11 E TIME OF GNSS POSITION UPDATE: 03 MAY 23 085308 UTC TIME SINCE GNSS LOCATION GENERATED: 0 MINUTES ALTITUDE OF GNSS LOCATION: 125 METRES (410 FEET) DOA - 02 25.1 N 046 06.2 E ESTIMATED ERROR 001NMS
5. OTHER INFORMATION BEACON CHARACTERISTICS PER TAC DATABASE PROVIDED IN A SEPARATE MESSAGE GNSS POSITION UNCERTAINTY PLUS-MINUS 10 METRES ELAPSED TIME SINCE ACTIVATION: 0 HOURS REMAINING BATTERY CAPACITY BETWEEN 75 AND 100 PERCENT DETECTION FREQUENCY 406.05 MHZ ELT(DT) POSITION DOES NOT REFERENCE ANY PREVIOUS POSITION
6. REMARKS THIS DISTRESS TRACKING MESSAGE IS BEING SENT TO APPROPRIATE SAR AUTHORITIES. PROCESS THIS ALERT ACCORDING TO RELEVANT REQUIREMENTS. END OF MESSAGE

6–28

Notes: 1. Paragraph 3: The beacon type is “SGB ELT”, and the beacon subtype is “DISTRESS TRACKING”, 2. Paragraph 3: The beacon has been activated by the G-switch, indicating a likely crash of the airplane. 3. Paragraph 4: Time since GNSS location is provided by the SGB. 4. Paragraph 4: The altitude of the GNSS location is an accurate value provided in metres (and feet). 5. Paragraph 5: For all SGBs, uncertainty of GNSS position provided in the alert message is approximately 10 metres. 6. Paragraph 5: SGBs may provide their remaining battery capacity within a range of percentage values. 7. Paragraph 6: Because of the large frequency spectrum that characterize an SGB, the value is set to “406.05 MHZ” for any SGB if no DOA position is provided, otherwise it is set to the actual detected value.

6–29

6.9 Cancellation Alerts A cancellation is sent to indicate that the activation event is no longer active (for example, hereafter, the events generating the ELT(DT) automatic triggering have returned to normal values). An activation can only be cancelled using the same means that triggered the activation (i.e., by avionics or manually). This cancellation message is for an SGB ELT(DT); cancellation messages may also be sent for FGB ELT(DT)s and for other types of SGBs. Notes:

1. Paragraph 1: The beacon message type is “USER CANCELLATION ALERT”.
2. Paragraph 3: The beacon was previously activated by the avionics, and the condition that prompted the activation has returned to normal. The beacon type indicates “SGB”, and a corresponding 23 Hexadecimal ID is provided in “HEX ID” line.
3. Paragraph 5: The System has received at least three (3) cancellation messages from the beacon within 110 seconds, with no intervening “non-cancellation message”, and the message indicates “CANCELLATION CONFIRMED”.
4. DISTRESS TRACKING COSPAS-SARSAT USER CANCELLATION ALERT
5. MSG NO 00192 AUMCC REF B274FA041FD4710
6. BEACON MESSAGE INFORMATION BEACON TYPE SGB – ELT DISTRESS TRACKING AIRCRAFT 24 BIT ADDRESS 7100CE ASSIGNED TO SAUDI ARABIA AIRCRAFT OPERATOR DESIGNATOR SVA TAC 16001 SERIAL NO 509 HEX ID B274FA041FD4 7100CEA3F00 COUNTRY OF BEACON REGISTRATION 403/SAUDI ACTIVATION TYPE AUTOMATIC BY EXTERNAL MEANS (AVIONICS)
7. ALERT POSITION INFORMATION DETECTED AT 03 MAY 24 085810 UTC BY MEOSAR ALERT LAST DETECTED AT 03 MAY 24 085310 UTC DOA – 02 25.1 N 046 06.2 E ESTIMATED ERROR UNKNOWN
8. OTHER INFORMATION ELT(DT) POSITION DOES NOT REFERENCE ANY PREVIOUS POSITION CANCELLATION CONFIRMED BEACON CHARACTERISTICS PER TAC DATABASE PROVIDED IN A SEPARATE MESSAGE REMAINING BATTERY CAPACITY BETWEEN 75 AND 100 PERCENT DETECTION FREQUENCY 406.0510 MHZ
9. REMARKS THIS DISTRESS TRACKING MESSAGE IS BEING SENT TO APPROPRIATE SAR AUTHORITIES PROCESS THIS ALERT ACCORDING TO RELEVANT REQUIREMENTS END OF MESSAGE

6–30

6.10 Sample SIT 985 Message with SGB Characteristics Based on TAC Number In the following sample, the reference (REF) is provided as a 15 HEX ID and a 5-digit alert site number. The associated MCC sends a single SIT 985 message to a Distress authority to accompany the first SIT 185 alert message sent to the Distress authority for the SGB activation, as available, based on the TAC number encoded in the beacon message.

1. BEACON OPERATIONAL CHARACTERISTICS
2. MSG NO 00192 AUMCC REF ADD481135B60000 - 21348
3. HEX ID ADD481135B60 00000000000
4. CHARACTERISTICS FOR TAC 12345 – MANUFACTURER: APPLIED TECHNOLOGY CORP.

• BEACON MODEL: XXXYYY-01234
• BEACON TYPE: PLB
• BEACON SUBTYPE: FLOAT-FREE
• TEMPERATURE RANGE: -40C +55C
• HOMING: 121.5=5 MW - 406=25 MW - AIS=20 MW
• NAV DEVICE: GALILEO, GLONASS
• STROBE: BRIGHTNESS=0.75 CANDELA, DUTY-CYCLE=15 FLASH/MINUTE END OF MESSAGE

6–31

6.11 A Ship Security Alert SSAS (Ship Security Alert System) beacons are processed in the same manner as EPIRBs, ELTs and PLBs, except that the SIT 185 message is not sent to the SAR Service associated with the beacon location; instead, the SIT 185 message is sent to the Competent Authority in the country of registration. Typically, the Competent Authority has a security focus rather than the rescue focus of a SAR Service. In the following example of a ship security alert, the beacon is first detected as an unlocated initial alert and then as an initial located alert with two Doppler locations. 6.11.1 An Unlocated Ship Security Alert

1. SHIP SECURITY COSPAS-SARSAT INITIAL ALERT(UNLOCATED)
2. MSG NO 00285 AUMCC REF 401917C900FFBFF
3. BEACON MESSAGE INFORMATION BEACON TYPE STANDARD LOCATION - SHIP SECURITY MMSI ALL 9 DIGITS 512573000 HEX ID 401917C900FFBFF COUNTRY OF BEACON REGISTRATION 512/NEWZEALAND ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY EXTERNAL DEVICE
4. ALERT POSITION INFORMATION DETECTED AT 07 JAN 23 2020 UTC BY GEOSAR GOES 17
5. OTHER INFORMATION LUT ID 5123 DETECTION FREQUENCY 406.0278 MHZ
6. REMARKS THIS IS A SHIP SECURITY ALERT. PROCESS THIS ALERT ACCORDING TO RELEVANT SECURITY REQUIREMENTS. END OF MESSAGE Notes:

This is an example of a ship security alert transmitted to a competent authority. MCCs would transmit this alert to the AUMCC for forwarding to the New Zealand relevant authority irrespective of the location of the alert. 2. The activation type provided in Paragraph 3 will always indicate “MANUAL” for an SSAS beacon, which can only be activated manually. 3. The graphics depiction of this alert is provided in Figure 6.12.

6–32

6.11.2 A Ship Security Initial Alert with Positions An initial located alert is generated for the same beacon with two Doppler locations.

1. SHIP SECURITY COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 00286 AUMCC REF 401917C900FFBFF
3. BEACON MESSAGE INFORMATION BEACON TYPE STANDARD LOCATION - SHIP SECURITY MMSI ALL 9 DIGITS 512573000 HEX ID 401917C900FFBFF COUNTRY OF BEACON REGISTRATION 512/NEWZEALAND ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY EXTERNAL DEVICE
4. ALERT POSITION INFORMATION DETECTED AT 07 JAN 23 2023 UTC BY LEOSAR SARSAT 13 DOPPLER A - 29 05 N 090 18 W PROB 76 PERCENT DOPPLER B - 40 13 N 039 02 W PROB 24 PERCENT
5. OTHER INFORMATION THE B POSITION IS LIKELY TO BE AN IMAGE POSITION DETECTION FREQUENCY 406.0278 MHZ
6. REMARKS THIS IS A SHIP SECURITY ALERT. PROCESS THIS ALERT ACCORDING TO RELEVANT SECURITY REQUIREMENTS. END OF MESSAGE Notes:

A second alert was received for this beacon incident. A ship security alert is processed like any other beacon incident except that the SIT 185 message is sent to the Competent Authority for the country of registration. 2. This ship security beacon has the capability to provide a GNSS position (as it is coded with a Location protocol) but in this case, no GNSS position was transmitted in the beacon message received by the LEOLUT. 3. Doppler position B with 24% probability has been further identified as being the likely image position given the initial GEOSAR detection. See the graphics in Figure 6.12.

6–33

Figure 6.12: Ship Security Unlocated and Initial Alert In the Figure 6.12 above, the orange line indicates the track of LEOSAR satellite Sarsat-13. The orange area is the footprint of Sarsat-13 at the TCA for the beacon. The GOES-17 footprint is indicated by the yellow line. The section of the Sarsat-13 footprint that overlaps with the GOES-17 footprint is shaded in light grey. The Doppler B location generated by the Sarsat-13 pass is outside the GOES-17 footprint, and hence, is reported as likely to be the image position.

6–34

6.12 An Alert with an Invalid Beacon Message A beacon message is invalid when a LUT is unable to correct errors in the beacon message or the MCC detects an invalid value associated with the beacon message. All the fields in an invalid beacon message are omitted or reported as “NIL” in the SIT 185 message, except for the Hex ID which (even though it is reported) may also be invalid. Any DOA or Doppler location data is valid and is reported in the SIT 185 message. 6.12.1 An Alert with an Invalid Beacon Message

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 79416 AUMCC REF 7722B4600017491
3. BEACON MESSAGE INFORMATION DATA DECODED FROM THE BEACON MESSAGE IS NOT RELIABLE HEX ID 7722B4600017491
4. ALERT POSITION INFORMATION DETECTED AT 09 JUN 23 0701 UTC BY LEOSAR COSPAS 14 DOPPLER A - 18 36.66 S 146 11.05 E PROB 66 PERCENT DOPPLER B - 13 02.22 S 171 15.38 E PROB 34 PERCENT
5. OTHER INFORMATION DETECTION FREQUENCY 406.0367 MHZ
6. REMARKS NIL END OF MESSAGE Notes:

Despite the error detection and correction capability of the system, the LUT was not able to correct all errors in the beacon message received for this particular detection. As a consequence, Paragraph 3 indicates that the decoded data is not reliable and the various beacon message fields are omitted because they are not reliable. 2. Note that the Hex ID of the beacon “7722B4600017491” decodes as an orbitography beacon with an invalid country code which suggests the Hex ID is invalid and should be treated with caution by an RCC. The Hex ID for every invalid beacon message should be treated with caution, since the invalid information may not be evident from the decoded Hex ID. 3. The invalid beacon message does not imply that the Doppler location is invalid as the Doppler location is generated from the beacon transmission, not the contents of the beacon message. The Doppler location in alerts with an invalid beacon message has been used to rescue persons in distress. 6.13 An Alert with a Satellite Manoeuvre Warning The Cospas-Sarsat LEOSAR satellites sometimes have to undergo a manoeuvre to adjust the orbit of the satellite. After the satellite orbit has changed, LEOLUTs may have inaccurate orbit information for the satellite and may generate a position that is outside normal accuracy. A warning is included in SIT 185 messages for 24 hours after a satellite manoeuvre when the expected error for Doppler positions computed with data from a manoeuvred satellite may exceed ten (10) kilometres.

6–35

6.13.1 An Initial Alert (with a Satellite Manoeuvre Warning) An initial alert has been generated for the beacon with Hex ID “BEEE43A58C0022D” but the satellite used to determine the position has recently undergone a manoeuvre for which the maximum expected impact in Doppler location accuracy has exceeded ten (10) kilometres within 24 hours of this manoeuvre.

1. DISTRESS COSPAS-SARSAT INITIAL LOCATED ALERT
2. MSG NO 76380 AUMCC REF BEEE43A58C0022D
3. BEACON MESSAGE INFORMATION BEACON TYPE SERIAL USER LOCATION - EPIRB (NON FLOAT FREE) SERIAL NO 0059747 HEX ID BEEE43A58C0022D COUNTRY OF BEACON REGISTRATION 503/AUSTRALIA BEACON NUMBER ON AIRCRAFT OR VESSEL NIL HOMING SIGNAL 121.5 MHZ ACTIVATION TYPE MANUAL GNSS POSITION PROVIDED BY NIL EMERGENCY CODE NIL
4. ALERT POSITION INFORMATION DETECTED AT 14 JAN 23 2310 UTC BY LEOSAR SARSAT 11 GNSS - NIL MCC REFERENCE – NIL DOPPLER A - 39 15.04 S 151 15.77 E PROB 54 PERCENT DOPPLER B - 37 56.05 S 144 36.48 E PROB 46 PERCENT
5. OTHER INFORMATION RELIABILITY OF DOPPLER POSITION DATA SUSPECT DUE TO SATELLITE MANOEUVRE DETECTION FREQUENCY 406.0280 MHZ TAC 0139 BEACON MODEL - STANDARD COMMS, AUSTRALIA MT400
6. REMARKS NIL END OF MESSAGE Notes:

This alert was generated within 24 hours of a manoeuvre of the Sarsat-11 satellite and contains a related warning in Paragraph 5.

6–36

6.14 An Interferer Alert An interferer is a signal transmitting between 406.0 to 406.1 MHz that does not have the correct signal structure for a Cospas-Sarsat distress beacon. Interferers with a location are reported to the appropriate spectrum authority. While there is no defined SIT 185 message format for reporting interferer alerts, the sample message below is provided per national procedure. 6.14.1 An Initial Interferer Alert

1. DISTRESS COSPAS-SARSAT 406 MHZ INTERFERER ALERT
2. MSG NO 37533 THMCC REF 88047/88048
3. BEACON MESSAGE INFORMATION HEX ID NIL
4. ALERT POSITION INFORMATION DETECTED AT 16 MAY 23 0311 UTC BY LEOSAR SARSAT 13 DOPPLER A - 17 40 N 096 11 E PROB 50 PERCENT DOPPLER B - 16 59 N 099 34 E PROB 50 PERCENT
5. OTHER INFORMATION DETECTION FREQUENCY 406.0170 MHZ
6. REMARKS PLEASE ADVISE YOUR SPECTRUM AGENCY OF ANY PERSISTENT INTERFERER END OF MESSAGE Note:

An interferer does not have a Hex ID, so no Hex ID is provided in Paragraph 3. An interferer reference number is provided in Paragraph 2. 2. The comments in Paragraph 6 request that the spectrum agency be advised of persistent interferers.

6–37

Figure 6.13: 406-MHz Interferer Alert In the Figure 6.13 above, the yellow line marks the track of LEOSAR satellite Sarsat- 13. The footprint for Sarsat-13 at the TCA for the interferer detection is shown by the orange outline. The two Doppler locations for the interferer are shown.

• END OF SECTION 6 –

7–1

FREQUENTLY ASKED QUESTIONS 7.1 What is the difference between an RCC and a SPOC? Answer: An RCC is a Rescue Coordination Centre and provides a SAR response within a declared SAR region designated by IMO and ICAO. Cospas-Sarsat uses the term SPOC (SAR Point of Contact) as a generic term to refer to the SAR agencies sent SIT 185 alerts by an MCC. Many but not all SPOCs are RCCs. The list of SPOCs with their contact details is available on the Cospas-Sarsat website. 7.2 What Cospas-Sarsat training is available for Distress authority personnel? Answer: Cospas-Sarsat document C/S P.015 includes a description of a model Cospas-Sarsat training course for SAR Service personnel. 7.3 My Distress authority needs to discuss the contents of a Cospas-Sarsat distress alert with an MCC. Where can it find contact information for the MCC? Answer: The contact information for MCCs is provided on the Cospas-Sarsat website (www.cospas-sarsat.int). 7.4 My Distress authority has a question on a particular aspect of the Cospas-Sarsat system and is unable to find the answer in the Handbook. Who should the Distress authority contact to discuss the matter? Answer: The Distress authority should contact its supporting MCC in the first instance for assistance. To establish your supporting MCC check Annex C and then the Cospas-Sarsat website (www.cospas-sarsat.int) for the MCC contact details. 7.5 What is the Hex ID? Why does a Distress authority need to know this Hex ID when the serial identity of the beacon is provided in Paragraph 3 in a manner that can be clearly understood by Distress authority personnel? Answer: See section 2.4 for an explanation of Hex ID. MCCs worldwide use this Hex ID in the main to refer to a beacon and to undertake searches for specific beacon activations in their system. It should be noted that the Hex ID is unique and no two identical Hex IDs should exist on two different beacons. Furthermore, most 406 MHz beacon registration databases use the Hex ID as the primary field. Distress authority personnel will facilitate discussions with MCCs on distress alerts if reference is made to the Hex ID. The serial identity provided for some beacon protocols in Paragraph 3 of the alert message received by the Distress authority is decoded from the Hex ID and provides information in respect of the beacon coding protocol used, the beacon type and the specific identity of the source or carrier, such as the Callsign. 7.6 How can I decode the 15 character Hex ID? Answer: There are several stand-alone programs available for this purpose. The Cospas-Sarsat website provides an online capability.

7–2

7.7 Why has the Distress authority received a MEOSAR alert but not a LEOSAR alert for a beacon? Why does the LEOSAR system sometimes detect a beacon but not the MEOSAR system? Answer: The system may provide a MEOSAR detection but not a LEOSAR detection if there is no LEOSAR satellite that has passed over the beacon. The LEOSAR satellites do not continuously cover the surface of the earth, but each LEOSAR satellite covers the earth in approximately 12 hours. Alternatively, a LEOSAR satellite may have passed over the beacon, but the beacon transmission may have been shielded from the LEOSAR satellite, such as when the beacon is in a mountainous region, a canyon or gorge. The LEOSAR satellites have a lower altitude orbit (between 700 and 1000 kilometres) so are able to detect weaker signals than the MEOSAR satellites which have an altitude of 19,000 to 24,000 kilometres. The weaker signal may be due to a damaged beacon or shielding if the beacon is activated indoors for example. 7.8 The Distress authority has received multiple CONFLICT alerts for the same LEOSAR beacon event, i.e., same satellite, same beacon Hex ID and same TCA (± 20 minutes). Why is this? Answer: In all probability, the alerts are from different LEOLUTs, albeit the same beacon event. Different LEOLUTs may generate different Doppler locations because different beacon bursts were available from the satellite due to the different LEOLUT locations, detection capability or time of acquisition. Different processing algorithms or orbital configuration data could result in different Doppler locations, even when two LEOLUTs use the same beacon bursts. A subsequent Doppler position conflict alert for the same beacon event is transmitted unless the new alert is determined to be of poorer quality. 7.9 The TCA in the LEOSAR distress alert just received is some four (4) hours old. Why is this? Answer: This happens when a LEOLUT tracks a particular satellite which it had not tracked for many hours and receives the recorded detection from an earlier orbit. It is assumed that the beacon had not been detected on subsequent passes by that particular satellite. 7.10 Position update alerts are being received multiple times after position confirmation, but the MCC reference position provided is changing. Why is this? Furthermore, why is the GNSS position remaining constant during this exchange? Answer: In some MCCs, an MCC reference position is calculated based on the most current location data and the historical locations that meet the distance matching criterion. The MCC reference position may be biased to the location with the smaller likely error. No two locations will be identical even when the same data from a satellite is used for processing. The GNSS position will remain constant if it was received from an external source that is not providing updates, if the beacon is not

7–3

designed to provide updates (likely an older beacon model), or if a Location Protocol FGB’s location has not changed by at least four (4) seconds of latitude and longitude. (Since its component longitude and latitude are each rounded to the nearest four (4) seconds, a Location Protocol FGB’s position could change by nearly six (6) seconds without a change in the GNSS position; i.e., Square Root of (4*4 + 4*4) = 5.66.) 7.11 Paragraph 5 of a Cospas-Sarsat distress alert reports that the Doppler A position is probably the image location, and it has a probability of 79%. Does this mean that B position is confirmed? Furthermore, why is the A position with a higher probability considered the image position? Is there a problem with the location processing? Answer: The determination that one position is probably an image does not indicate that the other position is confirmed; confirmation of a Doppler location only occurs by matching it with independent locations. On occasion, the Doppler location with the lesser probability is in fact the real position of the distress, so this should not be construed as an anomaly. The reference to “image position” is made when one position in a Doppler solution is within the footprint of another satellite that detected the beacon, and the other Doppler position is not within the satellite footprint. 7.12 The SAR Service has received a 406 MHz interferer alert. What should the RCC do with this information? Answer: Persistent 406 MHz interferer transmissions negatively impact the Cospas-Sarsat system and should be turned off. They should be reported to the national spectrum agency, who may deal with them directly (for internal sources) or report them to the ITU (for foreign sources). More information on 406 MHz interference is provided in the Cospas-Sarsat document C/S A.003, “Cospas-Sarsat System Monitoring and Reporting”. 7.13 What does it mean when the alert states that the GNSS position update time is within four (4) hours of detection time? Why isn’t a precise time provided? Answer: Unfortunately, the time associated with the GNSS position is not part of the beacon transmission as there are not enough data bits available to transmit the time. The alert states that the location was updated within four (4) hours of the detection time because the 406 MHz Beacon Specification (C/S T.001) requires that GNSS position not be transmitted if it has not been updated within four (4) hours. An alert indicating an “internal” source for the GNSS position is likely within a few minutes of the detection time (although the beacon is not required to update its GNSS position). In addition, when the GNSS position changes on a subsequent alert, the update time of the GNSS position is between the two reported detection times.

7–4

7.14 The alert provides 6 Hex characters for an ELT 24-bit address. What is the 24- bit address and how is it useful to a SAR Service? Is there a database that lists all these six (6) Hex characters? Answer: The aircraft 24-bit address is used in applications which require the routing of information to or from individual, suitably equipped aircraft. Examples of this are the aeronautical fixed telecommunication network (AFTN), SSR Mode S, and the airborne collision avoidance system (ACAS). The 24-bit address transmitted by an ELT is expressed as six hexadecimal characters in the distress alert and can be used to identify the precise aircraft provided an appropriate database is maintained. The 24-bit address can also identify the country that assigned it, and thus assist an RCC in its fact-finding efforts. The allocation of 24-bit aircraft addresses, formerly known as Mode S addresses, is described in the ICAO convention, Chapter 9 of Annex 10, Volume III. Alternatively, contact your State-aircraft-registration authority. 7.15 How is it useful for the Distress authority to be notified that the GNSS position was provided by an external device? Is it useful for the Distress authority to know that the activation type is “NIL”? Answer: The advice that the GNSS position is provided by an external device indicates that the beacon does not have an integral GNSS which can provide updated positions as long as the beacon remains active. An external input from a ship’s or aircraft’s GNSS (or other navigation system) will indicate that the GNSS position is unlikely to be updated after initial activation (as the beacon is usually separated from the external input). The activation type is only available with the user protocol and not supported in any of the location protocols. A manual activation type indicates that the beacon was activated by a survivor. A manual or automatic activation type indicator is probably not useful. 7.16 Paragraph 3 of the Cospas-Sarsat distress alert provides information on “beacon number on aircraft or vessel”. What is the significance of this information? Why does this Paragraph often indicate “NIL” or “0” (zero)? Answer: Certain beacon coding protocols, e.g., Maritime User and Radio Callsign User protocols, allow multiple beacons to be coded with the same callsign or MMSI. In order to differentiate between these beacons on board the same vessel and to provide a unique Hex ID, the beacon is coded with a specific beacon number, 0 to 9 and A to Z. If the vessel carries only one such coded beacon, then the specific number will be zero. Receiving a distress alert with the specific beacon number given as, say 1, indicates that there are additional beacons on board the vessel. 7.17 The Distress authority has received an alert for the first time for a beacon indicating a position conflict alert. How is this possible when the Distress authority did not receive a prior alert? Answer: For non-SSAS alerts, the initial alert might have been transmitted to another SAR Service because the initial location or locations were in that SAR Service’s

7–5

SRR. The subsequent alert, which is in conflict, contains positions in the subject SAR Service’s SRR. Alternatively, the position conflict alert sent to the Distress authority may contain a GNSS position that does not match either the DOA or Doppler location in the alert. 7.18 The Distress authority has reported that it has received message number 00533 from its support MCC as per Paragraph 2 of the distress alert message. However, the previous message number received was 00530. The Distress authority wishes to account for all messages and requests an explanation. Answer: A communication problem could cause messages to be missed. The Distress authority should request the support MCC to retransmit any missing messages. 7.19 Why does the MCC send regular communication checks to my SAR Service? Should I respond to the communication check? Answer: The IMO and ICAO have noted that there are known and documented problems in regard to SAR Services initiating SAR action in response to Cospas- Sarsat distress alerts. It was further noted that there were cases where the Cospas- Sarsat System successfully delivered distress alerts but the SAR Service did not respond. It was recognised that the fault lay in the SAR response system and not with the delivery of alerts by Cospas-Sarsat MCCs. For this reason, IMO and ICAO have requested that Cospas-Sarsat MCCs undertake regular communication checks with the SAR Services they support. SAR Services should respond promptly to the MCC when they receive a communication check. 7.20 Are there examples of how independence is determined when matching locations? Answer: Here are some examples of how an MCC determines if two locations can be used to determine a matching location: A GNSS position from a MEOLUT and a GNSS position from a LEOLUT can not confirm location, even if the two GNSS positions are the same, as the two GNSS positions come from the same source (the beacon) and can never be assumed to be independent. A Doppler location and a GNSS position confirm a location if the two locations match (i.e., are within 20 kilometres of each other) as a Doppler location and a GNSS position are independent of each other. Data from LEOSAR satellite Sarsat-10 gives two Doppler locations (L1 and L2) and DOA data from a MEOLUT gives location L3. If L1 and L3 match, then the MCC will provide an MCC reference position derived from L1 and L3. A Doppler location generated by satellite Sarsat-12 from one LEOLUT and a Doppler location generated by satellite Sarsat-12 with the same TCA from a different

7–6

LEOLUT would not confirm the location as the Doppler locations are from the same beacon event. Data from LEOSAR satellite Sarsat-12 gives two Doppler locations (L1 and L2) and data from LEOSAR satellite Sarsat-12 gives two Doppler locations (L3 and L4). If the second pair of locations have a different TCA (i.e., are from a different satellite pass) and only L1 and L3 match, then the location is confirmed. The MCC will provide an MCC reference position derived from L1 and L3. Data from LEOSAR satellite Sarsat-10 gives two Doppler locations (L1 and L2) and data from LEOSAR satellite Sarsat-12 gives two Doppler locations (L3 and L4), and there are two matches, both L1 and L3, as well as L2 and L4. This situation is known as an Unresolved Doppler Match and the second pair of Doppler locations does not confirm a location. A DOA location with three satellites (X1, X2, X3) with time T1 and a DOA location with four satellites (X2, X3, X6, X7) with time T2. If the two locations match, then if the times are not within two (2) seconds and as each satellite set has a unique satellite combination (X1 is not in the second set and X6 is not in the first set), the location is confirmed. A DOA location with three satellites (X1, X2, X3) with time T1 and a DOA location with four satellites (X1, X2, X3, X4) with time T2. If the times are within 30 minutes, then as the satellite sets are not different (the first set of satellites is contained in the second set) the location is not confirmed, even if the two locations match. If two DOA locations match and the data times for the two alerts differ by at least 30 minutes, then the location is confirmed, regardless of the sets of satellites. Data from a LEOLUT gives two Doppler locations: the A-position has a probability of 97% and the B-location has a probability of 3%. Despite the strong indication that the A-position is the real location of the beacon, the location is not confirmed as in some cases the location of the beacon will be the B-position. An MCC may be able to use footprint information to indicate which of two Doppler locations is likely to be the image location (i.e., the location that is not the location of the beacon). For example, if a beacon is detected by a GEOSAR satellite and there are two Doppler locations from a LEOSAR detection, and if one location is outside the footprint of the GEOSAR satellite, then it is likely that this is the image location. Despite this information, footprint determination is not used to confirm a location. See section 6.2 for an example of this processing. 7.21 How is the nine-digit MMSI formed using the six digits provided in a SIT 185? Answer: For beacons coded with an MMSI protocol, Paragraph 3 of the SIT 185 provides the last six digits of the Maritime Mobile Service Identity (MMSI). The nine-digit MMSI is formed by adding the six digits to the country code provided in the country of registration field. Note that some countries have more than one country code (known as the Maritime Identification Digits (MID)). For example, Panama has seven country codes, so there could be seven nine-digit MMSIs with the same last six digits provided in Paragraph

7–7

3. If the beacon has not been correctly coded with correct MID, then the resulting nine-digit MMSI will not be correct. Similarly, it is possible that a beacon with a particular MMSI is transferred to a different vessel without the beacon being re-programmed with the MMSI of the new vessel. Incidents have occurred where a beacon with an MMSI has been activated that does not match the MMSI of the vessel in distress. 7.22 Why does a beacon take 50 seconds to transmit its first burst once activated? Answer: Except for ELT(DT)s, Cospas-Sarsat FGBs are designed to have a 50- second warm-up time to allow the oscillator frequency to stabilize before the beacon begins transmitting. For the LEOSAR system, an unstable oscillator frequency would probably generate an inaccurate location estimate. Cospas-Sarsat FGB ELT(DT)s and SGBs require transmission of the first burst shortly after beacon activation. 7.23 What is the difference between a coarse GNSS position and a refined GNSS position? Answer: The data transmitted in the message from a distress beacon includes error- correcting codes that allow a LUT to fix some errors in the data. The data from an FGB has two components known as PDF-1 (Protected Data Field 1) and PDF-2 (Protected Data Field 2). An FGB message may have a valid PDF-1 but an invalid PDF-2 that cannot be corrected by the error-correcting codes. An FGB message with a valid PDF-1 that contains GNSS position, and an invalid PDF-2 will provide a coarse GNSS position. The coarse GNSS position is less accurate than the refined GNSS position that is provided when both data fields are valid. For example, consider an FGB with a National Location protocol with the GNSS position (33 23.73 S, 150 19.60 E). The GNSS position is contained in the beacon message as a coarse GNSS position (33 24.00 S, 150 18.00 E) with an adjustment of -0.27 minute latitude and +1.6 minute longitude. The coarse location is contained in the PDF-1 field and the fine adjustment is contained in the PDF-2 field. If the PDF-1 field is valid but the PDF-2 field is invalid (as it has too many errors), the GNSS position will be reported in the SIT 185 message as (33 24.00 S, 150 18.00 E). If the LUT detects a later transmission that has valid PDF-1 and PDF-2 fields, then the refined GNSS position of (33 23.73 S, 150 19.60 E) will be sent to the MCC. SGB messages only contain a single error-correcting code and the precision of a GNSS position is always the same for an SGB (i.e., approximately 10 metres). The alert message sent from an MCC to a Distress authority indicates the precision for a GNSS position. 7.24 Could the following confusing incident be explained? The New Zealand RCC received an initial alert for beacon 400E70784B59A9F with two Doppler locations and no GNSS position and later received a position confirmed alert for

7–8

beacon 400E70784AFFBFF containing a Doppler location and a GNSS position that matched, and an MCC reference position. The MCC reference position was near one of the Doppler locations in the initial alert. Were two beacons active? If it was the same beacon, why were the Hex IDs different (but similar) and why did the first detection not have a GNSS position? Answer: There was only one beacon in this incident. The initial alert contained a warning in Paragraph 3 that the data decoded from the beacon message was not reliable. For this reason, the GNSS position, which is part of the beacon message, was suppressed and not included in the first SIT 185 message sent to the New Zealand RCC. When a LUT receives a beacon message, it performs processing on the data to produce the Hex ID. As the first beacon message was invalid, the LEOLUT did not perform the processing on the Hex ID and this is why it is different (but similar) to the Hex ID in the position confirmed alert. Any Hex ID associated with a SIT 185 with a warning that the data is not reliable should be treated with caution by a Distress authority. Although the data in a beacon message may be invalid, the Doppler or DOA locations in such a message are valid, as demonstrated in this incident, as one of the Doppler locations in the initial alert was very near the actual location of the beacon. 7.25 Where can a SAR Service get more information about the Return Link Service function in the MEOSAR system? Answer: The Return Link Service (RLS) is described in a video available at https://www.cospas-sarsat.int/en/search-and-rescue/programme-videos-en. A SAR Service should contact its supporting MCC to obtain more information about the RLS. 7.26 What is the difference between an LG MCC and an LGM MCC? Answer: An LG MCC is an MCC that is only capable of processing LEOSAR and GEOSAR data. An LGM MCC is an MCC that is capable of processing LEOSAR, GEOSAR and MEOSAR data. MEOSAR is the most recent satellite system added to the Cospas-Sarsat system. Before the introduction of MEOSAR, all MCCs were LG MCCs. An LG MCC must be upgraded and commissioned in order to become an LGM MCC. 7.27 Why does my Distress authority receive multiple DOA position update alerts with the same detection time (as reported in Paragraph 3 of the SIT 185 message)? Answer: This could occur for two reasons:

1. The new alert contains a DOA position with better expected accuracy, as indicated in Paragraph 4.

7–9

2. While the new alert contains the same first detection time (per Paragraph 4), the new alert contains new detection data, as indicated by the last detection time reported in the subsequent data line. Except for ELT(DT)s, an updated DOA position alert is sent if the new alert contains data that is newer than data in all previous alerts, by at least five (5) minutes before position confirmation and at least 15 minutes after position confirmation. 7.28 What is an ELT(DT)? Answer: An ELT(DT) is a distress tracking ELT, which is Cospas-Sarsat’s version of an Autonomous Distress Tracking device to comply with the requirements of ICAO Annex 6. It is used to provide information about the location of an aircraft that is in a potential distress situation. An ELT(DT) may be activated when an aircraft’s avionics instrumentation has determined that the flight characteristics are sufficiently abnormal that the aircraft is in imminent danger of an accident. An ELT(DT) may also be activated manually by the crew or automatically due to the G-switch (probable crash), like other ELTs. 7.29 Is an ELT(DT) like other ELTs? Answer: Conceptually, an ELT(DT) is only required to meet ICAO Annex 6 requirements for Autonomous Distress Tracking devices. However, the Cospas- Sarsat Beacon Performance Specifications (documents C/S T.001 and C/S T.018) include provisions to ensure that an ELT(DT) will be designed to meet the same standard requirements as an ELT(AF), ELT(AP) or ELT(AD), for capabilities such as: • automatic G-switch activation, • beacon transmit frequency, • beacon message structure, However, ELT(DT)s transmit very frequently soon after activation (i.e., every 5 seconds within the first 120 seconds), to help ensure that an accurate location is provided in the event of an imminent crash. Unlike other ELT(s), ELT(DT)s may be activated automatically while in flight due to the aircraft avionics detecting abnormal flight characteristics. While other ELTs are required to have a 24-hour battery capacity, an ELT(DT) is only required to have a 370-minute battery capacity, unless it is crash-survivable. 7.30 If the aircraft is still in flight, why is this ELT(DT) alert message sent to the Distress authority? Answer: ELT(DT)s transmit automatically when the aircraft’s avionics detects anomalous conditions indicating that the aircraft is in imminent danger of crashing. In the first 120 seconds after activation, an ELT(DT) transmits every five (5) seconds so that its location can be accurately determined in the event of a crash. Once an aircraft crashes, its ELT(DT) (or other emergency equipment) may be unable to transmit properly. In short, ELT(DT) alerts are sent to Distress authorities so that

7–10

these authorities can respond properly to an aircraft that is in imminent danger of crashing. In addition, nodal MCCs automatically send ELT(DT) incident alert data to the Location of Aircraft in Distress Repository (LADR), which is operated for ICAO as a part of the Global Aeronautical Distress and Safety System.

• END OF SECTION 7 –

A-1

ANNEX A ACRONYMS AND TERMINOLOGY ACRONYM TERMINOLOGY ACAS Airborne Collision Avoidance System ADT Autonomous Distress Tracking AFTN Aeronautical Fixed Telecommunication Network ALMCC Algeria Mission Control Centre ARCC Aeronautical Rescue Coordination Centre ARMCC Argentina Mission Control Centre ASMCC South Africa Mission Control Centre ATSU Air Traffic Service Unit AUMCC Australia Mission Control Centre BDS BeiDou Navigation Satellite System of China (People’s Republic of) BRMCC Brazil Mission Control Centre BT Begin Transmission C/S Cospas-Sarsat CDDR Central Data Distribution Region CHMCC Chile MCC CMC Cospas Mission Centre (Russian Federation) CMCC Canada Mission Control Centre CNMCC China Mission Control Centre COSPAS Cosmicheskaya Sistema Poiska Avariynich Sudov (Russian for Space System for the Search of Vessels in Distress) CSTA Cospas-Sarsat Type Approval CYMCC Cyprus Mission Control Centre DDP Data Distribution Plan DDR Data Distribution Region DOA Difference of Arrival EDDR Eastern Data Distribution Region EHE Expected Horizontal Error ELT Emergency Locator Transmitter ELT(DT) Emergency Locator Transmitter for Distress Tracking EPIRB Emergency Position-Indicating Radio Beacon FGB First Generation Beacon (per document C/S T.001) FMCC France Mission Control Centre FOA Frequency of Arrival GADSS Global Aeronautical Distress and Safety System Galileo European global navigation satellite system GEOLUT Local User Terminal for GEOSAR GEOSAR Geostationary Earth Orbit Search and Rescue GHz Giga Hertz GLONASS Russian global navigation satellite system GMDSS Global Maritime Distress and Safety System

A-2

ACRONYM TERMINOLOGY GNSS Global Navigation Satellite System GOES Geostationary Operational Environmental Satellite GPS Global Positioning System (USA) GRMCC Greece Mission Control Centre Hex ID Hexadecimal identifier HKMCC Hong Kong Mission Control Centre IAMSAR International Aeronautical and Maritime Search and Rescue IBRD International Beacon Registration Database ICAO International Civilian Aviation Organization IDMCC Indonesia Mission Control Centre IMO International Maritime Organization INMCC India Mission Control Centre INSAT Indian Satellite ITMCC Italy Mission Control Centre ITU International Telecommunication Union JAMCC Japan Mission Control Centre JRCC Joint Rescue Coordination Centre KOMCC Korea Mission Control Centre LADR Location of an Aircraft in Distress Repository LEOLUT Local User Terminal for LEOSAR LEOSAR Low-altitude Earth Orbit Search and Rescue LP-STD Location Protocol - Standard LUT Local User Terminal LUT ID Local User Terminal Identifier MCC Mission Control Centre MEOLUT Local User Terminal for MEOSAR MEOSAR Medium-altitude Earth Orbit Search and Rescue MHz Mega Hertz MID Maritime Identification Digits MMSI Maritime Mobile Service Identity MSG Message MSG Meteosat Second Generation (EUMETSAT Satellite) MTG Meteosat Third Generation (EUTMETSAT Satellite) MYMCC Malaysia Mission Control Center NM Nautical Mile NMCC Norway Mission Control Centre NOCR Notification of Country of Registration NIMCC Nigeria Mission Control Centre NWPDDR North-West Pacific Data Distribution Region PAMCC Pakistan Mission Control Centre PDF Protected Data Field PEMCC Peru Mission Control Centre PLB Personal Locator Beacon

A-3

ACRONYM TERMINOLOGY QAMCC Qatar Mission Control Center RCC Rescue Coordination Centre REF Reference RLM Return Link Message RLS Return Link Service RLSP Return Link Service Provider SAMCC Saudi Arabia Mission Control Center SAR Search and Rescue SARP Search and Rescue Processor SARR Search and Rescue Repeater SARSAT Search and Rescue Satellite-Aided Tracking SCDDR South Central Data Distribution Region SGB Second Generation Beacon (per document C/S T.018) SID Standard Interface Description SIMCC Singapore Mission Control Centre SIT Subject Indicator Type SOLAS Safety of Life at Sea SPMCC Spain Mission Control Centre SPOC Search and Rescue Point of Contact SRR Search and Rescue Region SSAS Ship Security Alert System SSR Secondary Surveillance Radar SWPDDR South-West Pacific Data Distribution Region TAC Type-Approval Certificate (number) TAMCC ITDC Mission Control Centre (Chinese Taipei) TCA Time of Closest Approach TDOA Time Difference of Arrival TGMCC Togo Mission Control Center THMCC Thailand Mission Control Centre TOA Time of Arrival TRMCC Türkiye Mission Control Centre UKMCC United Kingdom of Great Britain and Northern Ireland Mission Control Centre USMCC USA Mission Control Centre UTC Universal Coordinated Time VNMCC Vietnam Mission Control Centre WDDR Western Data Distribution Region Abbreviations and acronyms used in this document are also defined in document C/S S.011 “Cospas-Sarsat Glossary”, available on the Cospas-Sarsat website at https://www.cospas-sarsat.int/en/documents-pro/system-documents

• END OF ANNEX A –

B-1

ANNEX B LIST OF MID (COUNTRY CODES) This table is a copy of the list of MID (Maritime Identification Digits) on the Cospas-Sarsat website (as of 1 December 2021) (see also ITU website at https://www.itu.int/en/ITU- R/terrestrial/fmd/Pages/mid.aspx). Name MID Abrv 3 Abrv 10 Adelie Land

ADE ADELIELAND Afghanistan

AFG AFGHAN Alaska (State of) (USA)

ALA ALASKA Albania

ALB ALBANIA Algeria

ALG ALGERIA American Samoa

ASA SAMOA USA Andorra

AND ANDORRA Angola

ANG ANGOLA Anguilla

ANA ANGUILLA Antigua and Barbuda

ANT ANTIGUA Antigua and Barbuda

ANT ANTIGUA Argentina

ARG ARGENTINA Armenia

ARM ARMENIA Aruba

ARU ARUBA Ascension Island

ASC ASCENSION Australia

AUS AUSTRALIA Austria

AUT AUSTRIA Azerbaijan

AZR AZERBAIJAN Azores

AZC AZORES Bahamas

BAA BAHAMAS Bahamas

BAA BAHAMAS Bahamas

BAA BAHAMAS Bahrain

BAH BAHRAIN Bangladesh

BAN BANGLADESH Barbados

BAR BARBADOS Belarus

BLR BELARUS Belgium

BEL BELGIUM Belize

BEZ BELIZE Benin

BEN BENIN Bermuda

BER BERMUDA Bhutan

BHU BHUTAN Bolivia

BOL BOLIVIA Bosnia and Herzegovina

BOS BOSNIAHERZ Botswana

BOT BOTSWANA Brazil

BRA BRAZIL

B-2

Name MID Abrv 3 Abrv 10 British Virgin Islands

BVI VIRGIN GB Brunei Darussalam

BRU BRUNEI Bulgaria

BUL BULGARIA Burkina Faso

BUF BURKINA FS Burundi

BUI BURUNDI Cambodia

CMB CAMBODIA Cambodia

CMB CAMBODIA Cameroon

CAM CAMEROON Canada

CAN CANADA Cape Verde

CAP CAPE VERDE Cayman Islands

CAY CAYMAN IS Central African Republic

CAR CENAFR REP Chad

CHA CHAD Chile

CHI CHILE China

CHN CHINA China

CHN CHINA China

CHN CHINA Chinese Taipei

TAI TAIPEI Christmas Island

CHR CHRISTMAS Cocos (Keeling) Islands

COC COCOS ISLE Colombia

COL COLOMBIA Comoros

COM COMOROS Comoros

COM COMOROS Congo

CON CONGO Cook Islands

COO COOK ISLES Costa Rica

COS COSTA RICA Côte d'Ivoire (Ivory Coast)

IVO IVORY COAST Croatia

CRT CROATIA Crozet Archipelago

CRP CROZET Cuba

CUB CUBA Cyprus

CYP CYPRUS Cyprus

CYP CYPRUS Cyprus

CYP CYPRUS Czech Republic

CZH CZECH REP Democratic People's Republic of Korea

KDR KOREA NOR Democratic Republic of the Congo

ZAI ZAIRE Denmark

DEN DENMARK Denmark

DEN DENMARK Djibouti

DJI DJIBOUTI Dominica

DOM DOMINICA Dominican Republic

DOR DOMINICAN Ecuador

ECU ECUADOR

B-3

Name MID Abrv 3 Abrv 10 Egypt

EGY EGYPT El Salvador

ELS ELSALVADOR Equatorial Guinea

EQG EQ GUINEA Eritrea

ERT ERITREA Estonia

EST ESTONIA Eswatini

SWA ESWATINI Ethiopia

ETH ETHIOPIA Falkland Islands (Malvinas)1

FAL FALKLAND I Faroe Islands

FAR FARO ISLE Fiji

FIJ FIJI Finland

FIN FINLAND France

FRA FRANCE France

FRA FRANCE France

FRA FRANCE French Polynesia

PLY POLYNESIA Gabon

GAB GABON REP Gambia

GAM GAMBIA Georgia

GOG GEORGIA Germany

GER GERMANY Germany

GER GERMANY Ghana

GHA GHANA Gibraltar

GIB GIBRALTAR Greece

GRE GREECE Greece

GRE GREECE Greece

GRE GREECE Greece

GRE GREECE Greenland

GRN GREENLAND Grenada

GRA GRENADA Guadeloupe (French Dept. of)

GUA GUADELOUPE Guatemala

GUT GUATEMALA Guiana (French Dept. of)

GUI GUIANA Guinea

GUN GUINEA REP Guinea-Bissau

GUB GUINEA BIS Guyana

GUY GUYANA Haiti

HAI HAITI Honduras

HON HONDURAS Hong Kong, China

HKG HONG KONG Hungary

HUN HUNGARY Iceland

ICE ICELAND 1 A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and the Northern Island concerning the sovereignty over the Falkland Islands (Malvinas).

B-4

Name MID Abrv 3 Abrv 10 India

IND INDIA Indonesia

INO INDONESIA Iran

IRN IRAN Iraq

IRQ IRAQ Ireland

IRE IRELAND Israel

ISR ISRAEL Italy

ITA ITALY Jamaica

JAM JAMAICA Japan

JPN JAPAN Japan

JPN JAPAN Jordan

JOR JORDAN Kazakhstan

KAZ KAZAKHSTAN Kenya

KEN KENYA Kerguelen Islands

KER KERGUELEN Kiribati

KIR KIRIBATI Korea (Republic of)

KOR KOREA SOU Korea (Republic of)

KOR KOREA SOU Kuwait

KUW KUWAIT Kyrgyz Republic

KYR KYRGYZIA Laos

LAO LAO Latvia

LAT LATVIA Lebanon

LEB LEBANON Lesotho

LES LESOTHO Liberia

LIB LIBERIA Liberia

LIB LIBERIA Libya

LBY LIBYA Liechtenstein

LIE LIECHTEN Lithuania

LIT LITHUANIA Luxembourg

LUX LUXEMBOURG Macao, China

MAC MACAO Madagascar

MAD MADAGASCAR Madeira

MAE MADEIRA Malawi

MAW MALAWI Malaysia

MLY MALAYSIA Maldives

MAV MALDIVES Mali

MLI MALI Malta

MAL MALTA Malta

MAL MALTA Malta

MAL MALTA Malta

MAL MALTA Malta

MAL MALTA Marshall Islands

MAR MARSHALL I

B-5

Name MID Abrv 3 Abrv 10 Martinique (French Dept. of)

MTQ MARTINIQUE Mauritania

MAA MAURITANIA Mauritius

MAU MAURITIUS Mexico

MEX MEXICO Micronesia

MIC MICRONESIA Moldova

MOL MOLDOVA Monaco

MON MONACO Mongolia

MNG MONGOLIA Montenegro

MNT MONTENEGRO Montserrat

MOT MONTSERRAT Morocco

MOR MOROCCO Mozambique

MOZ MOZAMBIQUE Myanmar

BUR BURMA Namibia

NAM NAMIBIA Nauru

NAU NAURU Nepal

NEP NEPAL Netherlands (The)

NET NETHERLAND Netherlands (The)

NET NETHERLAND Netherlands (The)

NET NETHERLAND Netherlands Antilles (formerly-). Sint Maarten (Dutch part); Bonaire, Sint Eustatius and Saba; and Curacao

NEA N ANTILLES New Caledonia

NCA CALEDONIA New Zealand

NZL NEWZEALAND Nicaragua

NIC NICARAGUA Niger

NIG NIGER Nigeria

NIA NIGERIA Niue

NIU NIUE ISLE North Macedonia (Republic of)

MKD NORTH MAC Northern Mariana Islands

MAI MARIANA IS Norway

NOR NORWAY Norway

NOR NORWAY Norway

NOR NORWAY Oman

OMN OMAN Pakistan

PAK PAKISTAN Palau

PAL PALAU Palestine

PAA PALESTINE Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA

B-6

Name MID Abrv 3 Abrv 10 Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Panama

PAN PANAMA Papua New Guinea

PAP PAPUA NG Paraguay

PAR PARAGUAY Peru

PER PERU Philippines

PHI PHILIPPINE Pitcairn

PIT PITCAIRN I Poland

POL POLAND Portugal

POR PORTUGAL Puerto Rico

PUE PUERTORICO Qatar

QAT QATAR Réunion (La) (same country code for Mayotte)

REU REUNION Romania

ROM ROMANIA Russian Federation

RUS RUSSIA Rwanda

RWA RWANDA Saint Kitts and Nevis

SKN ST KITTS Saint Lucia

SLU ST LUCIA Saint Paul and Amsterdam Islands

SPL ST PAUL Saint Vincent and the Grenadines

SVG ST VINCENT Saint Vincent and the Grenadines

SVG ST VINCENT Saint Vincent and the Grenadines

SVG ST VINCENT Samoa

WSA WEST SAMOA San Marino

SAN SAN MARINO Sao Tome and Principe

SAO SAO TOME Saudi Arabia

SAU SAUDI Senegal

SEN SENEGAL Serbia

SER SERBIA Seychelles

SEY SEYCHELLES Sierra Leone

SIL SIERRA LEO Singapore

SIN SINGAPORE Singapore

SIN SINGAPORE Singapore

SIN SINGAPORE Singapore

SIN SINGAPORE Slovak Republic

SLV SLOVAKIA Slovenia

SVN SLOVENIA

B-7

Name MID Abrv 3 Abrv 10 Solomon Islands

SOL SOLOMON IS Somalia

SOM SOMALI South Africa

SAF SO AFRICA South Sudan

SSD SOUTHSUDAN Spain

SPA SPAIN Spain

SPA SPAIN Sri Lanka

SRI SRI LANKA St. Helena

SHE ST HELENA St. Pierre and Miquelon (French Dept. of)

SPI ST PIERRE Sudan

SUD SUDAN Suriname

SUR SURINAME Sweden

SWE SWEDEN Sweden

SWE SWEDEN Switzerland

SWT SWISS Syria

SYR SYRIA Tajikistan

TJK TAJIKISTAN Tanzania

TAN TANZANIA Tanzania

TAN TANZANIA Thailand

THA THAILAND Timor-Leste

TIM TIMORLESTE Togo

TOG TOGO Tonga

TON TONGA Trinidad and Tobago

TAT TRINIDAD Tunisia

TUN TUNISIA Türkiye

TUR TURKIYE Turkmenistan

TKM TURKMENIST Turks and Caicos Islands

TUK CAICOS IS Tuvalu

TUV TUVALU IS Uganda

UGA UGANDA Ukraine

UKR UKRAINE United Arab Emirates

UAE UAE United Arab Emirates

UAE UAE United Kingdom of Great Britain and Northern Ireland

UKM G BRITAIN United Kingdom of Great Britain and Northern Ireland

UKM G BRITAIN United Kingdom of Great Britain and Northern Ireland

UKM G BRITAIN United Kingdom of Great Britain and Northern Ireland

UKM G BRITAIN United States of America

USA USA United States of America

USA USA

B-8

Name MID Abrv 3 Abrv 10 United States of America

USA USA United States of America

USA USA United States of America

USA USA United States Virgin Islands

USV VIRGIN US Uruguay

URU URUGUAY Uzbekistan

UZB UZBEKISTAN Vanuatu

VAN VANUATU Vanuatu

VAN VANUATU Vatican City State

VAT VATICAN Venezuela

VEN VENEZUELA Vietnam

VIE VIETNAM Wallis and Futuna Islands

WAL WALLIS IS Yemen

YEM YEMEN Yemen

YEM YEMEN Zambia

ZAM ZAMBIA Zimbabwe

ZIM ZIMBABWE

B-9

This table listing the MID codes in order uses data from the Cospas-Sarsat website downloaded (as of 1 November 2019) (see also ITU website at https://www.itu.int/en/ITU- R/terrestrial/fmd/Pages/mid.aspx). MID Name Abrv 3 Abrv 10

Albania ALB ALBANIA

Andorra AND ANDORRA

Austria AUT AUSTRIA

Azores AZC AZORES

Belgium BEL BELGIUM

Belarus BLR BELARUS

Bulgaria BUL BULGARIA

Vatican City State VAT VATICAN

Cyprus CYP CYPRUS

Cyprus CYP CYPRUS

Germany GER GERMANY

Cyprus CYP CYPRUS

Georgia GOG GEORGIA

Moldova MOL MOLDOVA

Malta MAL MALTA

Armenia ARM ARMENIA

Germany GER GERMANY

Denmark DEN DENMARK

Denmark DEN DENMARK

Spain SPA SPAIN

Spain SPA SPAIN

France FRA FRANCE

France FRA FRANCE

France FRA FRANCE

Malta MAL MALTA

Finland FIN FINLAND

Faroe Islands FAR FARO ISLE

United Kingdom of Great Britain and Northern Ireland UKM G BRITAIN

United Kingdom of Great Britain and Northern Ireland UKM G BRITAIN

United Kingdom of Great Britain and Northern Ireland UKM G BRITAIN

United Kingdom of Great Britain and Northern Ireland UKM G BRITAIN

Gibraltar GIB GIBRALTAR

Greece GRE GREECE

Croatia CRT CROATIA

Greece GRE GREECE

B-10

MID Name Abrv 3 Abrv 10

Greece GRE GREECE

Greece GRE GREECE

Morocco MOR MOROCCO

Hungary HUN HUNGARY

Netherlands (The) NET NETHERLAND

Netherlands (The) NET NETHERLAND

Netherlands (The) NET NETHERLAND

Italy ITA ITALY

Malta MAL MALTA

Malta MAL MALTA

Ireland IRE IRELAND

Iceland ICE ICELAND

Liechtenstein LIE LIECHTEN

Luxembourg LUX LUXEMBOURG

Monaco MON MONACO

Madeira MAE MADEIRA

Malta MAL MALTA

Norway NOR NORWAY

Norway NOR NORWAY

Norway NOR NORWAY

Poland POL POLAND

Montenegro MNT MONTENEGRO

Portugal POR PORTUGAL

Romania ROM ROMANIA

Sweden SWE SWEDEN

Sweden SWE SWEDEN

Slovak Republic SLV SLOVAKIA

San Marino SAN SAN MARINO

Switzerland SWT SWISS

Czech Republic CZH CZECH REP

Türkiye TUR TURKIYE

Ukraine UKR UKRAINE

Russian Federation RUS RUSSIA

North Macedonia (Republic of) MKD NORTH MAC

Latvia LAT LATVIA

Estonia EST ESTONIA

Lithuania LIT LITHUANIA

Slovenia SVN SLOVENIA

Serbia SER SERBIA

Anguilla ANA ANGUILLA

Alaska (State of) (USA) ALA ALASKA

Antigua and Barbuda ANT ANTIGUA

B-11

MID Name Abrv 3 Abrv 10

Antigua and Barbuda ANT ANTIGUA

Netherlands Antilles (formerly-). Sint Maarten (Dutch part); Bonaire, Sint Eustatius and Saba; and Curacao NEA N ANTILLES

Aruba ARU ARUBA

Bahamas BAA BAHAMAS

Bahamas BAA BAHAMAS

Bermuda BER BERMUDA

Bahamas BAA BAHAMAS

Belize BEZ BELIZE

Barbados BAR BARBADOS

Canada CAN CANADA

Cayman Islands CAY CAYMAN IS

Costa Rica COS COSTA RICA

Cuba CUB CUBA

Dominica DOM DOMINICA

Dominican Republic DOR DOMINICAN

Guadeloupe (French Dept. of) GUA GUADELOUPE

Grenada GRA GRENADA

Greenland GRN GREENLAND

Guatemala GUT GUATEMALA

Honduras HON HONDURAS

Haiti HAI HAITI

United States of America USA USA

Jamaica JAM JAMAICA

Saint Kitts and Nevis SKN ST KITTS

Saint Lucia SLU ST LUCIA

Mexico MEX MEXICO

Martinique MTQ MARTINIQUE

Montserrat MOT MONTSERRAT

Nicaragua NIC NICARAGUA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Puerto Rico PUE PUERTORICO

El Salvador ELS ELSALVADOR

St. Pierre and Miquelon SPI ST PIERRE

Trinidad and Tobago TAT TRINIDAD

B-12

MID Name Abrv 3 Abrv 10

Turks and Caicos Islands TUK CAICOS IS

United States of America USA USA

United States of America USA USA

United States of America USA USA

United States of America USA USA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Panama PAN PANAMA

Saint Vincent and the Grenadines SVG ST VINCENT

Saint Vincent and the Grenadines SVG ST VINCENT

Saint Vincent and the Grenadines SVG ST VINCENT

British Virgin Islands BVI VIRGIN GB

United States Virgin Islands USV VIRGIN US

Afghanistan AFG AFGHAN

Saudi Arabia SAU SAUDI

Bangladesh BAN BANGLADESH

Bahrain BAH BAHRAIN

Bhutan BHU BHUTAN

China CHN CHINA

China CHN CHINA

China CHN CHINA

Chinese Taipei TAI TAIPEI

Sri Lanka SRI SRI LANKA

India IND INDIA

Iran IRN IRAN

Azerbaijan AZR AZERBAIJAN

Iraq IRQ IRAQ

Israel ISR ISRAEL

Japan JPN JAPAN

Japan JPN JAPAN

Turkmenistan TKM TURKMENIST

Kazakhstan KAZ KAZAKHSTAN

Uzbekistan UZB UZBEKISTAN

Jordan JOR JORDAN

Korea (Republic of) KOR KOREA SOU

Korea (Republic of) KOR KOREA SOU

Palestine PAA PALESTINE

Democratic People's Republic of Korea KDR KOREA NOR

Kuwait KUW KUWAIT

Lebanon LEB LEBANON

B-13

MID Name Abrv 3 Abrv 10

Kyrgyz Republic KYR KYRGYZIA

Macao, China MAC MACAO

Maldives MAV MALDIVES

Mongolia MNG MONGOLIA

Nepal NEP NEPAL

Oman OMN OMAN

Pakistan PAK PAKISTAN

Qatar QAT QATAR

Syria SYR SYRIA

United Arab Emirates UAE UAE

United Arab Emirates UAE UAE

Tajikistan TJK TAJIKISTAN

Yemen YEM YEMEN

Yemen YEM YEMEN

Hong Kong, China HKG HONG KONG

Bosnia and Herzegovina BOS BOSNIAHERZ

Adelie Land ADE ADELIELAND

Australia AUS AUSTRALIA

Myanmar BUR BURMA

Brunei Darussalam BRU BRUNEI

Micronesia MIC MICRONESIA

Palau PAL PALAU

New Zealand NZL NEWZEALAND

Cambodia CMB CAMBODIA

Cambodia CMB CAMBODIA

Christmas Island CHR CHRISTMAS

Cook Islands COO COOK ISLES

Fiji FIJ FIJI

Cocos (Keeling) Islands COC COCOS ISLE

Indonesia INO INDONESIA

Kiribati KIR KIRIBATI

Laos LAO LAO

Malaysia MLY MALAYSIA

Northern Mariana Islands MAI MARIANA IS

Marshall Islands MAR MARSHALL I

New Caledonia NCA CALEDONIA

Niue NIU NIUE ISLE

Nauru NAU NAURU

French Polynesia PLY POLYNESIA

Philippines PHI PHILIPPINE

Timor-Leste TIM TIMORLESTE

Papua New Guinea PAP PAPUA NG

B-14

MID Name Abrv 3 Abrv 10

Pitcairn PIT PITCAIRN I

Solomon Islands SOL SOLOMON IS

American Samoa ASA SAMOA USA

Samoa WSA WEST SAMOA

Singapore SIN SINGAPORE

Singapore SIN SINGAPORE

Singapore SIN SINGAPORE

Singapore SIN SINGAPORE

Thailand THA THAILAND

Tonga TON TONGA

Tuvalu TUV TUVALU IS

Vietnam VIE VIETNAM

Vanuatu VAN VANUATU

Vanuatu VAN VANUATU

Wallis and Futuna Islands WAL WALLIS IS

South Africa SAF SO AFRICA

Angola ANG ANGOLA

Algeria ALG ALGERIA

Saint Paul and Amsterdam Islands SPL ST PAUL

Ascension Island ASC ASCENSION

Burundi BUI BURUNDI

Benin BEN BENIN

Botswana BOT BOTSWANA

Central African Republic CAR CENAFR REP

Cameroon CAM CAMEROON

Congo CON CONGO

Comoros COM COMOROS

Cape Verde CAP CAPE VERDE

Crozet Archipelago CRP CROZET

Côte d'Ivoire (Ivory Coast) IVO IVORYCOAST

Comoros COM COMOROS

Djibouti DJI DJIBOUTI

Egypt EGY EGYPT

Ethiopia ETH ETHIOPIA

Eritrea ERT ERITREA

Gabon GAB GABON REP

Ghana GHA GHANA

Gambia GAM GAMBIA

Guinea-Bissau GUB GUINEA BIS

Equatorial Guinea EQG EQ GUINEA

Guinea GUN GUINEA REP

Burkina Faso BUF BURKINA FS

B-15

MID Name Abrv 3 Abrv 10

Kenya KEN KENYA

Kerguelen Islands KER KERGUELEN

Liberia LIB LIBERIA

Liberia LIB LIBERIA

South Sudan SSD SOUTHSUDAN

Libya LBY LIBYA

Lesotho LES LESOTHO

Mauritius MAU MAURITIUS

Madagascar MAD MADAGASCAR

Mali MLI MALI

Mozambique MOZ MOZAMBIQUE

Mauritania MAA MAURITANIA

Malawi MAW MALAWI

Niger NIG NIGER

Nigeria NIA NIGERIA

Namibia NAM NAMIBIA

Reunion (same country code for Mayotte) REU REUNION

Rwanda RWA RWANDA

Sudan SUD SUDAN

Senegal SEN SENEGAL

Seychelles SEY SEYCHELLE

St. Helena SHE ST HELENA

Somalia SOM SOMALI

Sierra Leone SIL SIERRA LEO

Sao Tome and Principe SAO SAO TOME

Eswatini SWA ESWATINI

Chad CHA CHAD

Togo TOG TOGO

Tunisia TUN TUNISIA

Tanzania TAN TANZANIA

Uganda UGA UGANDA

Democratic Republic of the Congo ZAI ZAIRE

Tanzania TAN TANZANIA

Zambia ZAM ZAMBIA

Zimbabwe ZIM ZIMBABWE

Argentina ARG ARGENTINA

Brazil BRA BRAZIL

Bolivia BOL BOLIVIA

Chile CHI CHILE

Colombia COL COLOMBIA

Ecuador ECU ECUADOR

B-16

MID Name Abrv 3 Abrv 10

Falkland Islands (Malvinas) 2 FAL FALKLAND I

Guiana (French Dept. Of) GUI GUIANA

Guyana GUY GUYANA

Paraguay PAR PARAGUAY

Peru PER PERU

Suriname SUR SURINAME

Uruguay URU URUGUAY

Venezuela VEN VENEZUELA

• END OF ANNEX B - 2 A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and the Northern Island concerning the sovereignty over the Falkland Islands (Malvinas).

C-1

ANNEX C COSPAS-SARSAT DATA DISTRIBUTION REGIONS C.1 WESTERN DDR Figure C.1: Western DDR Map

C-2

Countries/Regions and MIDs Supported by the Western DDR MCCs: ARMCC Argentina

Falklands Islands/Malvinas

BRMCC Brazil

Ascension

CHMCC Bolivia

Chile

Paraguay

Uruguay

CMCC Canada

St. Pierre and Miquelon

PEMCC Peru

USMCC Alaska

Aruba

Bahamas 308/309/311 Barbados

Belize

Bermuda

British Virgin Islands

Cayman Islands

Colombia

Costa Rica

Cuba

Dominican Republic 327 Ecuador

El Salvador

Grenada

Guatemala

Guyana

Haiti

Honduras

Jamaica

Marshall Islands

Mexico

Micronesia

Netherlands Antilles

Nicaragua

Northern Mariana Islands

Palau

Panama 351/352/353/354/ 355/356/357/370/ 371/372/373/374 Puerto Rico

St. Vincent and the Grenadines 375/376/377 Trinidad and Tobago

Turks and Caicos Islands

USA 338/366/367/368/

US Virgin Islands

Venezuela

C-3

C.2 NORTH WEST PACIFIC DDR Figure C.2: North West Pacific DDR Map Countries/Regions and MIDs Supported by the North-West Pacific DDR MCCs CNMCC China (P.R. of) 412/413 HKMCC Hong Kong, China

Macao, China

Philippines

Democratic People’s Rep. of Korea

JAMCC Japan 431/432 KOMCC Korea (Rep. of) 440/441 TAMCC Chinese Taipei

VNMCC Cambodia 514/515 Laos

Viet Nam

C-4

C.3 SOUTH WEST PACIFIC DDR Figure C.3: South West Pacific DDR Map Countries/Regions and MIDs Supported by the South West Pacific DDR MCCs ASMCC Angola

Botswana

Burundi

Dem. Rep. of Congo 676 Eswatini

Lesotho

Malawi

Mozambique

Namibia

Rwanda

South Africa

St. Helena

Uganda

Zambia

Zimbabwe

AUMCC Adelie Land

American Samoa 559 Australia

Christmas Island

Cocos Islands

Cook Islands

Fiji

Kiribati

Nauru

New Caledonia

New Zealand

Niue

Papua New Guinea 553 Saint Paul & Amsterdam 607 Samoa

Solomon Islands 557 Tonga

Tuvalu

Vanuatu

Wallis and Futuna 578 IDMCC Indonesia 525 Timor-Leste 550 SIMCC Brunei

Malaysia

Myanmar

Singapore 563/564/565 THMCC Thailand 567

C-5

C.4 CENTRAL DDR Figure C.4: Central DDR Map

C-6

Countries/Regions and MIDs Supported by the Central DDR MCCs CYMCC Cyprus 209/210/212 FMCC Andorra

Anguilla

Antigua and Barbuda 304/305 Austria

Azores

Belgium

Chad

Djibouti

Comoros

Crozet Archipelago 618 Dominica

France 226/227/228 French Guiana

French Polynesia

Germany 211/218 Gibraltar

Guadeloupe

Kerguelen Islands 635 Liechtenstein (Swiss) 252 Luxemburg

Madagascar

Madeira 255 Martinique

Mauritius

Monaco

Montserrat

Morocco

Netherlands 244/245/246 Pitcairn

Portugal

Reunion/Mayotte

Saint Kitts and Nevis 341 Saint Lucia

Suriname

Switzerland

Tunisia 672 GRMCC Greece 237/239/240 ITMCC Albania

Bosnia & Herzegovina

Croatia

Eritrea

Ethiopia

Israel

Italy

Kenya

Malta 215/248/249/256 Montenegro

North Macedonia

Palestine

San Marino

Serbia

Slovenia

Somalia

South Sudan

Sudan

Vatican City

NMCC Denmark 219/220 Estonia

Faroe Islands

Finland

Greenland

Iceland

Latvia

Lithuania

Norway 257/258/259 Poland

Sweden 265/266 TRMCC Afghanistan

Georgia*

Iran

Iraq

Türkiye

Ukraine* 272 UKMCC United Kingdom 232/233/234/235 Ireland 250

• See also CMC service area.

C-7

C.5 SOUTH CENTRAL DDR Figure C.5: South Central DDR Map Countries/Regions and MIDs Supported by the South-Central DDR MCCs AEMCC United Arab Emirates 470/471 ALMCC Algeria

Burkina Faso

Egypt

Libya

Niger

NIMCC Declared as “CNO” See SPMCC SAMCC Bahrain

Jordan

Kuwait

Lebanon

Oman

Saudi Arabia

Syria

Yemen 473/475 SPMCC Benin

Cameroon

Cape Verde

Central African Republic 612 Congo

Equatorial Guinea

Gabon

Gambia

Ghana

Guinea

Guinea-Bissau

Ivory Coast

Liberia 636/637 Mali

Mauritania

Sao Tome and Principe 668 Senegal

Sierra Leone

Spain 224/225 Togo

Nigeria

C-8

C.6 EASTERN DDR Figure C.6: Eastern DDR Map Countries/Regions and MIDs Supported by the Eastern DDR MCCs CMC Armenia

Azerbaijan

Belarus

Bulgaria

Czech Republic 270 Georgia*

Hungary

Kazakhstan

Kyrgyz Rep.

Moldova

Mongolia

Romania

Russia

Tajikistan

Turkmenistan

Ukraine*

Uzbekistan

INMCC Bangladesh

Bhutan

India

Maldives

Nepal

Seychelles

Sri Lanka

Tanzania 674/677 PAMCC Pakistan

• See also TRMCC service area.

• END OF ANNEX C -

D-1

ANNEX D HOW TO USE THE IBRD Annex D is sequence of slides that shows how a SAR Service can use the IBRD. Please send an email to admin@406registration.com for any questions.

D-2

D-3

D-4

D-5

D-6

D-7

– END OF ANNEX D – – END OF DOCUMENT –

Cospas-Sarsat Secretariat 1250 boulevard René-Lévesque West, Suite 4215, Montréal, Québec H3B 4W8 CANADA Telephone: + 1 514 500 9993 Fax: + 1 514 500 7996 Email: mail@cospas-sarsat.int Website www.cospas-sarsat.int