Ryan Malloy
4ed92efd69
Cospas-Sarsat specification summaries moved to reference/ for internal use only. Links updated to point to official cospas-sarsat.int site. The extracted images remain in public/ for use in other pages.
1415 lines
37 KiB
Markdown
1415 lines
37 KiB
Markdown
---
|
|
title: "R015: R.015"
|
|
description: "Official Cospas-Sarsat R-series document R015"
|
|
sidebar:
|
|
badge:
|
|
text: "R"
|
|
variant: "note"
|
|
# Extended Cospas-Sarsat metadata
|
|
documentId: "R015"
|
|
series: "R"
|
|
seriesName: "Reports"
|
|
documentType: "report"
|
|
isLatest: true
|
|
issue: 1
|
|
documentDate: "October 2009"
|
|
originalTitle: "R.015"
|
|
---
|
|
|
|
> **📋 Document Information**
|
|
>
|
|
> **Series:** R-Series (Reports)
|
|
> **Version:** Issue 1
|
|
> **Date:** October 2009
|
|
> **Source:** [Cospas-Sarsat Official Documents](https://www.cospas-sarsat.int/en/documents-pro/system-documents)
|
|
|
|
---
|
|
|
|
COSPAS-SARSAT
|
|
INSAT GEOSAR PERFORMANCE
|
|
EVALUATION REPORT
|
|
C/S R.015
|
|
Issue 1
|
|
|
|
|
|
INSAT PERFORMANCE EVALUATION REPORT
|
|
History
|
|
Issue
|
|
Revision
|
|
Date
|
|
Comments
|
|
Issue 1
|
|
-
|
|
|
|
Approved by CSC-43
|
|
|
|
LIST OF PAGES
|
|
Page \#
|
|
Date of
|
|
Page \#
|
|
Date of
|
|
latest
|
|
latest
|
|
revision
|
|
revision
|
|
cover
|
|
Oct 09
|
|
D-1
|
|
Oct 09
|
|
|
|
Oct 09
|
|
D-2
|
|
Oct 09
|
|
|
|
Oct 09
|
|
D-3
|
|
Oct 09
|
|
|
|
Oct 09
|
|
D-4
|
|
Oct 09
|
|
|
|
Oct 09
|
|
|
|
Oct 09
|
|
E-1
|
|
Oct 09
|
|
|
|
Oct 09
|
|
E-2
|
|
Oct 09
|
|
1-1
|
|
Oct 09
|
|
F-1
|
|
Oct 09
|
|
1-2
|
|
Oct 09
|
|
F-2
|
|
Oct 09
|
|
2-1
|
|
Oct 09
|
|
2-2
|
|
Oct 09
|
|
3-1
|
|
Oct 09
|
|
3-2
|
|
Oct 09
|
|
3-3
|
|
Oct 09
|
|
3-4
|
|
Oct 09
|
|
3-5
|
|
Oct 09
|
|
3-6
|
|
Oct 09
|
|
3-7
|
|
Oct 09
|
|
3-8
|
|
Oct 09
|
|
3-9
|
|
Oct 09
|
|
3-10
|
|
Oct 09
|
|
4-1
|
|
Oct 09
|
|
4-2
|
|
Oct 09
|
|
A-1
|
|
Oct 09
|
|
A-2
|
|
Oct 09
|
|
B-1
|
|
Oct 09
|
|
B-2
|
|
Oct 09
|
|
C-1
|
|
Oct 09
|
|
C-2
|
|
Oct 09
|
|
|
|
TABLE OF CONTENTS
|
|
Page
|
|
1.
|
|
INTRODUCTION ..................................................................................................... 1-1
|
|
1.1
|
|
Background ................................................................................................................. 1-1
|
|
1.2
|
|
INSAT GEOSAR Performance Evaluation ................................................................ 1-1
|
|
2.
|
|
INSAT GEOSAR PERFORMANCE EVALUATION
|
|
GOALS AND OBJECTIVES ................................................................................... 2-1
|
|
2.1
|
|
Performance Evaluation Goals .................................................................................... 2-1
|
|
2.2
|
|
Objectives .................................................................................................................... 2-2
|
|
2.3
|
|
Priorities ...................................................................................................................... 2-3
|
|
3.
|
|
INSAT PERFORMANCE EVALUATION RESULTS ......................................... 3-1
|
|
3.1
|
|
T-1:
|
|
Processing Threshold, System Margin and Beacon Message
|
|
Processing Performance ................................................................................ 3-1
|
|
3.2
|
|
T-2:
|
|
Time to Produce Valid, Complete and Confirmed Messages ....................... 3-3
|
|
3.3
|
|
T-3:
|
|
Carrier Frequency Measurement Accuracy .................................................. 3-4
|
|
3.4
|
|
T-4:
|
|
INSAT GEOLUT Channel Capacity ............................................................ 3-5
|
|
3.5
|
|
T-5:
|
|
Impact of Interference ................................................................................... 3-6
|
|
3.6
|
|
T-6:
|
|
Processing Anomaly Performance ................................................................ 3-6
|
|
3.7
|
|
T-7:
|
|
INSAT Coverage .......................................................................................... 3-7
|
|
3.8
|
|
C-1:
|
|
Commissioning of INSAT GEOLUT ........................................................... 3-8
|
|
4.
|
|
CONCLUSIONS ....................................................................................................... 4-1
|
|
|
|
LIST OF ANNEXES
|
|
Annex A :
|
|
Processing Threshold and System Margin Test Results .......................... A-1
|
|
Annex B :
|
|
Valid Message Processing Performance ...................................................B-1
|
|
Annex C :
|
|
Complete and Confirmed Complete Message Performance
|
|
Test Results ...............................................................................................C-1
|
|
Annex D :
|
|
Time to Produce Valid, Complete and Confirmed Complete
|
|
Messages Test Results ............................................................................. D-1
|
|
Annex E :
|
|
Frequency Measurement Accuracy Test Results ...................................... E-1
|
|
Annex F :
|
|
Capacity Test Results ............................................................................... F-1
|
|
LIST OF FIGURES
|
|
Figure 3.1 :
|
|
Vessel's Actual Course of Sailing, between the Two Stars,
|
|
GEOLUT Lost ......................................................................................... 3-7
|
|
Figure 3.2 :
|
|
INSAT-2B, Loss of Beacon Detection at 0 Elevation ........................... 3-8
|
|
Figure A-1 :
|
|
Processing Threshold and System Margin Performance (T1) ................. A-2
|
|
Figure B-1 :
|
|
Valid Message Processing Performance within 5 minutes (T1) ...............B-1
|
|
Figure C-1 :
|
|
Long Message Processing Performance (T1) ...........................................C-1
|
|
Figure D-1 :
|
|
Graphs Depicting Message Production Avg. Time (T2) ......................... D-2
|
|
Figure D-2 :
|
|
Graphs Depicting Message Production Time - 95th Percentile (T2) ....... D-2
|
|
Figure D-3 :
|
|
Graphs Depicting Message Production Time - 98th Percentile (T2) ....... D-3
|
|
Figure E-1 :
|
|
Average Frequency Measurement Accuracy Performance (T3) .............. E-1
|
|
Figure E-2 :
|
|
Average Frequency Measurement Standard Deviation Accuracy
|
|
Performance (T3) ...................................................................................... E-2
|
|
Figure F-1 :
|
|
INSAT GEOSAR Capacity (T4) .............................................................. F-1
|
|
|
|
LIST OF TABLES
|
|
Table 3.1 :
|
|
Processing Threshold and System Margin ............................................... 3-2
|
|
Table 3.2 :
|
|
Valid Message Processing Performance ................................................... 3-2
|
|
Table 3.3 :
|
|
Complete and Confirmed Complete Message Performance
|
|
at Processing Threshold (33 dBm Uplink) ............................................... 3-3
|
|
Table 3.4 :
|
|
Time to Produce Messages at Processing Threshold (33 dBm Uplink) ... 3-3
|
|
Table 3.5 :
|
|
Time to Produce Messages at Processing Threshold for the
|
|
95th Percentile (33 dBm Uplink) ............................................................... 3-4
|
|
Table 3.6 :
|
|
Capacity Performance Results Measured by Bangalore GEOLUT .......... 3-6
|
|
Table 3.7 :
|
|
Summary of the GEOLUT Commissioning Test Results ........................ 3-9
|
|
Table A-1 :
|
|
Analyzed Results for Objective T-1 ........................................................ A-1
|
|
Table D-1:
|
|
Analyzed Results for Objective T-2 ........................................................ D-1
|
|
Table E-1 :
|
|
Analyzed Results for Objective T-3 ......................................................... E-1
|
|
Table F-1 :
|
|
Capacity Statistics for Test Objective T-4 ................................................ F-1
|
|
|
|
- Page left blank -
|
|
|
|
1 - 1
|
|
|
|
1.
|
|
INTRODUCTION
|
|
The Indian Space Research Organisation (ISRO) has installed 406 MHz Search and Rescue
|
|
(SAR) repeaters on their INSAT communication and meteorological satellites. The first
|
|
INSAT satellites was launched in 1992 and following payload testing of the SAR instrument
|
|
and successful Cospas-Sarsat GEOSAR D&E was used operationally by Cospas-Sarsat
|
|
Ground Segment operators from February 1999. However, the performance of INSAT SAR
|
|
instrument had yet to be fully evaluated. The Cospas-Sarsat Council directed that an INSAT
|
|
GEOSAR performance evaluation programme be conducted to
|
|
a.
|
|
establish INSAT GEOSAR / GEOLUT performance;
|
|
b.
|
|
validate specification and commissioning requirements for GEOLUTs which operate
|
|
with the current INSAT-3A GEOSAR payload; and
|
|
c.
|
|
verify the performance and, if appropriate, commission the current INSAT GEOLUT
|
|
(Bangalore) into the Cospas-Sarsat System.
|
|
1.1
|
|
Background
|
|
From 1996 to 1998 Cospas-Sarsat conducted a demonstration and evaluation programme to
|
|
determine the suitability of using satellites in geostationary orbit equipped with SAR
|
|
instruments to process the signals from Cospas-Sarsat 406 MHz distress beacons. This
|
|
programme, hereafter referred to as the GEOSAR D & E, was implemented using the GOES
|
|
series of satellites provided by the USA, the Insat-2 satellites provided by India, and
|
|
experimental ground segment equipment provided by Canada, Chile, India, Spain and the
|
|
United Kingdom. The GEOSAR D & E demonstrated that GEOSAR satellites provided a
|
|
significant enhancement to the Cospas-Sarsat system. Following from this conclusion, in
|
|
October 1998 the Cospas-Sarsat Council decided that the 406 MHz GEOSAR system
|
|
components should be incorporated into the Cospas-Sarsat System as soon as possible.
|
|
While the GEOSAR D & E was being conducted, new 406 MHz GEOSAR repeaters were
|
|
developed by EUMETSAT and installed on the MSG meteorological satellite series. Since
|
|
the technical characteristics of the MSG SAR instrument were different from SAR
|
|
instruments on the GOES satellites, additional tests were performed to establish MSG
|
|
GEOSAR / GEOLUT performance, and any special GEOLUT specification and
|
|
commissioning requirements. The results of these tests were approved by Cospas-Sarsat in
|
|
October 2004.
|
|
1.2
|
|
INSAT GEOSAR Performance Evaluation
|
|
Following the deployment of a third type of 406 MHz GEOSAR payload onboard INSAT-3A
|
|
by the Republic of India and the signature of an Understanding between the Cospas-Sarsat
|
|
Programme and the Republic of India on the provision of Cospas-Sarsat GEOSAR services in
|
|
|
|
1 - 2
|
|
|
|
February 2007, the Cospas-Sarsat Council also decided that the INSAT performance
|
|
evaluation programme should be based on the technical (T) series of tests defined in the
|
|
GEOSAR D & E Plan, as amended to address anticipated INSAT performance.
|
|
The INSAT GEOLUT (Bangalore) participated in the INSAT GEOSAR performance
|
|
evaluation programme. Since the Bangalore terminal is the only Cospas-Sarsat GEOLUT
|
|
capable of tracking the INSAT-3A payload, the commissioning of the GEOLUT was also
|
|
performed as part of the INSAT GEOSAR performance evaluation.
|
|
The administrations of France and Turkey also participated in the INSAT GEOSAR
|
|
performance evaluation and provided beacon simulator signals for some of the proposed
|
|
tests.
|
|
The tests reported herein were performed while the INSAT 3A satellite was at its final
|
|
operating position of 93.5 E. France's 406 MHz beacon simulator with a linearly polarised
|
|
whip antenna was used to transmit the uplink signals developed specifically for the testing.
|
|
- END OF SECTION 1 -
|
|
|
|
2 - 1
|
|
|
|
2.
|
|
INSAT
|
|
GEOSAR
|
|
PERFORMANCE
|
|
EVALUATION
|
|
GOALS
|
|
AND
|
|
OBJECTIVES
|
|
2.1
|
|
Performance Evaluation Goals
|
|
The goals of the performance evaluation programme were to:
|
|
a.
|
|
characterize the technical performance of the INSAT GEOSAR / GEOLUT system
|
|
and confirm that the INSAT GEOSAR satellite, and GEOLUT systems effectively
|
|
provide useful 406 MHz alert data; and
|
|
b.
|
|
validate specification, commissioning requirements and performance for the
|
|
GEOLUT which operate with INSAT-3 satellites.
|
|
As Part of this evaluation programme, the INSAT GEOLUT was tested in accordance with
|
|
the commissioning requirements detailed in document C/S T.010 and, if appropriate, will be
|
|
commissioned into the Cospas-Sarsat System.
|
|
2.2
|
|
Objectives
|
|
The programme has been subdivided into specific objectives. Each objective is addressed by
|
|
conducting specific tests and analysing the results. Some of the tests were performed with a
|
|
beacon simulator whose power output and message content can be controlled and varied.
|
|
The tests were conducted over several weeks to collect enough data to provide statistically
|
|
valid results.
|
|
An overview of each objective is listed below, the detailed descriptions of these objectives
|
|
are provided in section 3.2.
|
|
T-1
|
|
Processing Threshold, System Margin, and Beacon Message Processing Performance
|
|
Determine the processing threshold, processing performance, system margin and the
|
|
performance in respect of long format beacon messages for GEOLUTs which operate
|
|
with the INSAT payload. The test signals used to assess these parameters do not
|
|
include beacon messages that collide with each other.
|
|
T-2
|
|
Time to Produce Valid and Confirmed Messages
|
|
Determine the statistical distribution of the time required for the GEOLUT to produce
|
|
valid and confirmed beacon messages. The test signals used to assess this parameter
|
|
do not include beacon messages which collide with each other.
|
|
|
|
2 - 2
|
|
|
|
T-3
|
|
Carrier Frequency Measurement Accuracy
|
|
Determine how accurately the beacon carrier frequency can be determined by the
|
|
INSAT GEOSAR / GEOLUT system. The test signals used to assess this parameter
|
|
do not include beacon messages which collide with each other.
|
|
T-4
|
|
INSAT GEOLUT Channel Capacity
|
|
Assess the capability of the GEOSAR system to handle multiple simultaneously
|
|
active distress beacons in a single 406 MHz channel. This parameter is assessed by
|
|
generating traffic loads which include beacon messages which collide with each other.
|
|
T-5
|
|
Impact of Interference
|
|
Monitor the band for the presence of interference while the tests are being performed,
|
|
in order to understand any anomalies in the results and to illustrate the ability of the
|
|
GEOSAR system to provide valid messages in the presence of interference and noise
|
|
in the frequency bands used by the INSAT GEOSAR system.
|
|
T-6
|
|
Processing Anomalies
|
|
Assess the performance of the GEOLUT in respect of the production of processing
|
|
anomalies.
|
|
T-7
|
|
INSAT Coverage
|
|
Estimate the geographic coverage of the INSAT GEOSAR system1.
|
|
C-1
|
|
Commissioning of the INSAT GEOLUT (Bangalore)
|
|
Verify the compliance of the INSAT GEOLUT to the Cospas-Sarsat performance and
|
|
design guidelines (specified in C/S T.009) by performing the tests specified in the
|
|
GEOLUT Commissioning Standard (C/S T.010) and reporting results in the
|
|
appropriate format to the Cospas-Sarsat Joint Committee for evaluation.
|
|
2.3
|
|
Priorities
|
|
In accordance with Cospas-Sarsat Council decisions, initial efforts focussed on completing
|
|
the most important tests which consisted of T-1 (processing threshold), T-2 (time to produce
|
|
a valid message) and C-1 (commissioning of the INSAT GEOLUT), with the understanding
|
|
that the other tests would be performed as time permit.
|
|
- END OF SECTION 2 -
|
|
1 Results from previous tests could be used to characterize the INSAT coverage.
|
|
|
|
3 - 1
|
|
|
|
3.
|
|
INSAT PERFORMANCE EVALUATION RESULTS
|
|
3.1
|
|
T-1: Processing Threshold, System Margin, and Beacon Message
|
|
Processing Performance
|
|
The processing threshold, processing performance and the system margin are "figures of
|
|
merit" of the GEOLUT, as defined below.
|
|
Processing Threshold
|
|
The processing threshold is the value of the minimum carrier to noise density ratio (C/N0) at
|
|
the GEOLUT processor for which the GEOLUT is able to produce a valid message for a
|
|
beacon event 99% of the time (the lower this value the more sensitive the GEOLUT). Equally
|
|
the processing threshold can be expressed in terms of the minimum beacon effective isotropic
|
|
radiated power (EIRP) for which the GEOLUT is able to produce a valid message 99% of the
|
|
time.
|
|
System Margin
|
|
The system margin is the difference between a nominal beacon (which by definition is a
|
|
beacon with an EIRP of 37 dBm) and a beacon operating at the GEOLUT threshold.
|
|
Valid Message Processing Performance
|
|
The processing performance requirement documented in C/S T.009 is that GEOLUTs should
|
|
be capable of producing valid messages within 5 minutes of beacon activation 95% of the
|
|
time, for all beacon signals whose C/No as measured at the GEOLUT is greater than
|
|
26 dB-Hz. This test will determine the C/No for which the INSAT GEOLUT can produce a
|
|
valid message for each beacon event within 5 minutes of beacon activation 95% of the time.
|
|
Long Message Processing Performance
|
|
Document C/S T.009 specifies the processing of long messages and the requirement for
|
|
confirmed complete messages. However, at present Cospas-Sarsat has no GEOLUT
|
|
performance requirement in respect of producing complete and confirmed long messages.
|
|
Nevertheless, with the increased use of location protocol beacons using the long message
|
|
format, it is necessary to assess the INSAT system performance in this regard.
|
|
3.1.1
|
|
Methodology and Data Collection
|
|
This test assesses the INSAT GEOLUT performance in respect of its ability to produce single
|
|
valid, complete and confirmed complete distress beacon messages as a function of the beacon
|
|
power transmitted in the direction of the INSAT satellite (beacon EIRP).
|
|
A beacon simulator is used to replicate distress beacons that transmit long format messages at
|
|
specific EIRPs, for a duration necessary to transmit 20 bursts for each beacon ID. Hereafter
|
|
the term "beacon event" is used to describe a beacon being active for a period of time. The
|
|
test is conducted by transmitting 50 beacon events for each EIRP, whilst ensuring that signals
|
|
|
|
3 - 2
|
|
|
|
from individual beacon events do not overlap in time and frequency with the signals from
|
|
other beacon events. The output of the GEOLUT is monitored and the information identified
|
|
in Table E-1 is recorded. The procedure is repeated at EIRP values ranging from 37 dBm to
|
|
28 dBm, in one dB increments.
|
|
3.1.2
|
|
Processing Threshold and System Margin
|
|
The processing threshold and system margin as evaluated by the Bangalore are provided at
|
|
Table 3.1 below. The detailed results are provided at Annex A.
|
|
Table 3.1: Processing Threshold and System Margin
|
|
GEOLUT
|
|
THRESHOLD
|
|
EIRP
|
|
(dBm)
|
|
THRESHOLD
|
|
GEOLUT C/N0
|
|
(dB-Hz)
|
|
SYSTEM
|
|
MARGIN
|
|
(dB)
|
|
NUMBER OF
|
|
BEACON
|
|
EVENTS USED
|
|
Bangalore
|
|
|
|
36.7
|
|
|
|
|
|
The results indicate that beacon signals greater than 33 dBm will be reliably detected by the
|
|
INSAT GEOSAR system. Below the threshold of 33 dBm the system performance degrades
|
|
rapidly, with a moderate percentage of the signals being detected with uplink EIRP values
|
|
less than 32 dBm.
|
|
3.1.3 Valid Message Processing Performance
|
|
The valid message processing performance is a measure of the GEOSAR system's ability to
|
|
provide a valid message within 5 minutes of beacon activation 95% of the time.
|
|
The minimum uplink EIRP required for the GEOLUTs to provide valid messages within 5
|
|
minutes is provided at Table 3.2 below. The detailed results are provided at Annex B.
|
|
Table 3.2: Valid Message Processing Performance
|
|
GEOLUT
|
|
THRESHOLD
|
|
EIRP
|
|
(dBm)
|
|
THRESHOLD
|
|
GEOLUT C/N0
|
|
(dB-Hz)
|
|
NUMBER OF
|
|
BEACON
|
|
EVENTS USED
|
|
Bangalore
|
|
|
|
36.7
|
|
|
|
The Bangalore GEOLUTs satisfies the message processing requirement for uplink signals
|
|
with an EIRP of 33 dBm. The results for the Bangalore GEOLUT is 96% detection of
|
|
beacon signal within 5 minutes (>95th percentile as required) at 33 dBm. However, it slightly
|
|
drop to 90% at 34 dBm due to presence of strong CW interfering signal in the band during
|
|
the test.
|
|
|
|
3 - 3
|
|
|
|
3.1.4 Complete and Confirmed Complete Message Performance
|
|
The performance of the Bangalore GEOLUT to produce complete and confirmed complete
|
|
messages for beacons with uplink signals at the system threshold level of 33 dBm is provided
|
|
at Table 3.3 below. The detailed performance of each GEOLUT at all measured uplink
|
|
signals is provided at Annex C.
|
|
Table 3.3: Complete and Confirmed Complete Message Performance
|
|
at Processing Threshold (33 dBm Uplink)
|
|
GEOLUT
|
|
COMPLETE
|
|
MESSAGE
|
|
PROBABILITY
|
|
CONFIRMED
|
|
COMPLETE
|
|
MESSAGE
|
|
PROBABILITY
|
|
NUMBER OF
|
|
BEACON
|
|
EVENTS USED
|
|
Bangalore
|
|
0.98
|
|
0.98
|
|
|
|
3.2
|
|
T-2: Time to Produce Valid, Complete and Confirmed Messages
|
|
This test assesses how long it takes INSAT GEOLUT operating with the INSAT-3A satellite
|
|
to produce valid beacon messages, complete long messages, and confirmed complete long
|
|
messages.
|
|
3.2.1 Methodology and Data Collection
|
|
For simplicity this test was conducted by analysing the data collected for test T-1
|
|
(Threshold). Note that the T-1 test scenario was specifically designed not to generate beacon
|
|
bursts which overlap in time and frequency. Consequently, for operational beacon events, the
|
|
times to produce valid, complete, and the time to confirm complete messages may differ from
|
|
those determined during this test.
|
|
3.2.2 Time to Produce Valid, Complete and Confirmed Complete Messages at
|
|
Threshold
|
|
Table 3.4 provides statistics in respect of the average time required for the Bangalore
|
|
GEOLUT to produce valid, complete and confirmed complete messages for beacon signals at
|
|
threshold.
|
|
Table 3.4: Time to Produce Messages at Processing Threshold (33 dBm Uplink)
|
|
GEOLUT
|
|
VALID MESSAGES
|
|
Avg / Standard Deviation
|
|
(Seconds)
|
|
COMPLETE MESSAGES
|
|
Avg / Standard Deviation
|
|
(Seconds)
|
|
CONFIRMED COMPLETE
|
|
MESSAGES
|
|
Avg / Standard Deviation
|
|
(Seconds)
|
|
Bangalore
|
|
172/78
|
|
172/78
|
|
289/75
|
|
* Statistics calculated from 50 beacon events
|
|
|
|
3 - 4
|
|
|
|
Table 3.5 provides statistics in respect of the time required to produce valid, complete and
|
|
confirmed complete messages for the 95th percentile, in respect of beacon signals that
|
|
transmit at the processing threshold of 33 dBm.
|
|
Table 3.5: Time to Produce Messages at Processing Threshold
|
|
for the 95th Percentile (33 dBm Uplink)
|
|
GEOLUT
|
|
VALID MESSAGES
|
|
(Seconds)
|
|
COMPLETE MESSAGES
|
|
(Seconds)
|
|
CONFIRMED COMPLETE
|
|
MESSAGES
|
|
(Seconds)
|
|
Bangalore
|
|
|
|
|
|
* Statistics calculated from 50 beacon events
|
|
The detailed data providing the time required for the GEOLUTs to produce valid, complete
|
|
and confirmed complete messages for signals with different transmit EIRPs are provided at
|
|
Annex D.
|
|
3.3
|
|
T-3: Carrier Frequency Measurement Accuracy
|
|
This test is to assess how accurately the beacon carrier frequency can be measured by the
|
|
INSAT GEOSAR / GEOLUT system. This is accomplished by comparing the beacon's
|
|
carrier frequency for each valid message as measured by the GEOLUT with the known
|
|
frequency value for the same beacon, provided by the beacon simulator operator. The current
|
|
GEOLUT specification (C/S T.009) requires a frequency measurement accuracy of 2 Hz.
|
|
3.3.1 Methodology and Data Collection
|
|
For simplicity, this test was conducted by analysing the data collected for test T-1. For each
|
|
beacon event the frequency measurement provided by the GEOLUT for the first valid
|
|
message produced was recorded.
|
|
The GEOLUT measured frequency included any calibration that would normally be
|
|
performed during actual GEOLUT operations (e.g. if the GEOLUT includes features for
|
|
assessing and correcting frequency measurements by applying calibration correction factors
|
|
and using reference beacons, these features should be activated).
|
|
3.3.2 Frequency Measurement Accuracy Results
|
|
The detailed results for the frequency measurement accuracy testing are provided at Annex E.
|
|
In summary, the frequency measurement accuracy of the Bangalore GEOLUT system less
|
|
2 Hz, but it was found to be a variation of 51 Hz in frequency of the beacons due to periodic
|
|
variation in the frequency at satellite LO, because of temperature variation during a day over
|
|
24h. However, short term stability is maintained well during the detection of a beacon by the
|
|
GEOLUT system. Onboard satellite oscillator (TCXO) used for frequency translation has
|
|
temperature based variation in frequency during 24h in cyclic manner at different sun angles
|
|
with respect to satellite.
|
|
|
|
3 - 5
|
|
|
|
3.4
|
|
T-4: INSAT GEOLUT Channel Capacity
|
|
The definition of capacity in Cospas-Sarsat GEOSAR systems is the number of 406 MHz
|
|
distress beacons operating simultaneously in the field of view of a GEOSAR satellite that can
|
|
be successfully processed by the System to provide a valid beacon message, under nominal
|
|
conditions, within 5 minutes of beacon activation 95% of the time.
|
|
3.4.1 Methodology and Data Collection
|
|
The INSAT GEOSAR channel capacity was assessed by generating traffic loads equivalent to
|
|
known numbers of simultaneously active long format beacons in a Cospas-Sarsat 406 MHz
|
|
channel. The time required for the GEOLUT to produce a valid beacon message, complete
|
|
message and confirm a complete message for each beacon event was recorded. The number
|
|
of simultaneously active beacon events was changed and the time required for the GEOLUT
|
|
to produce valid, complete and complete confirmed messages was calculated and recorded
|
|
for the new 406 MHz traffic load.
|
|
The test scripts transmitted by the beacon simulator conformed to the nominal conditions
|
|
detailed in the Cospas-Sarsat 406 MHz frequency management plan (document C/S T.012),
|
|
with the exception that the uplink EIRP was selected to be 37 dBm rather than 34 dBm. The
|
|
test replicated a number of beacon messages overlapping in time and frequency
|
|
commensurate with the number of simultaneously active beacons. Further, the beacon events
|
|
used in the test script also replicated the beacon burst repetition period defined in document
|
|
C/S T.001 (406 MHz beacon specification). The test was scheduled to avoid any potential
|
|
interference caused by Cospas-Sarsat LEOSAR satellite downlink transmissions.
|
|
INSAT GEOSAR system capacity test was carried out using 15, 20 and 25 beacons at
|
|
37 dBm EIRP. For 25 beacons, only 5 test scripts were only carried out due to shortage of
|
|
time. The results were plotted and observed that system provided 90% valid message
|
|
detections within 5 and 10 minutes). Looking at the trend of the plots, the results can be
|
|
extrapolated for 10 beacon system capacity using INSAT GEOLUT system, which was
|
|
originally planned.
|
|
The detailed results of the INSAT capacity tests are provided at Annex F.
|
|
3.4.2 Capacity Results
|
|
This test was performed by the Bangalore GEOLUT, and the resulting performance statistics
|
|
are provided at Table 3.6.
|
|
|
|
3 - 6
|
|
|
|
Table 3.6:
|
|
Capacity Performance Results Measured by Bangalore GEOLUT
|
|
NUMBER OF
|
|
ACTIVE
|
|
BEACONS
|
|
PROBABILITY
|
|
OF VALID
|
|
MESSAGE
|
|
WITHIN 5 MIN
|
|
PROBABILITY
|
|
OF VALID
|
|
MESSAGE
|
|
WITHIN 10 MIN
|
|
PROBABILITY
|
|
OF VALID
|
|
MESSAGE
|
|
WITHIN 15 MIN
|
|
PROBABILITY
|
|
OF CONFIRMED
|
|
COMPLETE
|
|
MESSAGE
|
|
WITHIN 15 MIN
|
|
\*10
|
|
>95
|
|
>95
|
|
>95
|
|
>95
|
|
|
|
|
|
\*
|
|
This test was not carried out due to shortage of time. By extrapolating the curve plotted for
|
|
15, 20 and 25 beacons, the results indicate that for beacon populations with uplink EIRP
|
|
values exceeding 37 dBm, the capacity would exceed detection of 10 simultaneous beacons
|
|
by INSAT GEOSAR system.
|
|
3.5
|
|
T-5: Impact of Interference
|
|
The INSAT GEOLUT system is generally configured for detection of beacons in operational
|
|
band only to avoid processing load on the system. Whenever there is need to test the system,
|
|
reference beacon band is configured to detect the beacons. INSAT GEOSAR operates with
|
|
extended C-band down link signal; hence there is no possibility of interference with the
|
|
LEOSAR downlink frequency. Prior to starting the test during the month of July-August
|
|
2009, the system was thoroughly tested and qualified in the entire processing band by
|
|
GEOLUT development team. During this period, there was no detection of any new beacon
|
|
in the reference frequency band other than known reference beacons (Kerguelen test beacon
|
|
9C7FEC2AACD3590 and Russian orbitography beacon A22249249249240). Hence, there
|
|
was no processing anomaly reported.
|
|
3.6
|
|
T-6: Processing Anomaly Performance
|
|
This test assesses GEOLUT performance in respect of its ability to suppress the processing
|
|
anomalies produced.
|
|
3.6.1
|
|
Processing Anomaly as a Function of Number of Beacon Bursts
|
|
This test is conducted by monitoring the 406 MHz channel (406.022 MHz) used by Cospas-
|
|
Sarsat reference beacon from the Kerguelen Island2, and noting instances where the
|
|
GEOLUT produced valid beacon messages which did not correspond to any of the reference
|
|
beacons in the coverage area of the INSAT-3A satellite. Since the identifications (IDs) of all
|
|
reference beacons in view of the INSAT satellite are known, it can be inferred that beacons
|
|
detected in the 406.022 MHz channel which do not correspond to known reference beacons
|
|
are processing anomalies.
|
|
2 The details of the Kerguelen Island beacon are as follow: Hex ID: 9C7EC2AACD3590, Country: France,
|
|
Location: 49o21.09' S 070o15.36' E, Freq: 406.021856, Transmission interval: 30 sec.
|
|
|
|
3 - 7
|
|
|
|
INSAT GEOSAR operates with extended C-band down link signal; hence there is no
|
|
possibility of interference with the LEOSAR downlink frequency. Prior to starting the test
|
|
during the month of July-August 2009, the system was thoroughly tested and qualified in the
|
|
entire processing band by GEOLUT development team. During this period, there was no
|
|
detection of any new beacon in the reference frequency band other than known reference
|
|
beacons (Kerguelen test beacon 9C7FEC2AACD3590 and Russian orbitography beacon
|
|
A22249249249240). Hence, there was no processing anomaly reported.
|
|
3.7
|
|
T-7: INSAT Coverage
|
|
The coverage of the INSAT GEOSAR system is evaluated using a combination of:
|
|
a.
|
|
technical tests, in which a beacon is activated for a period of time, during which it
|
|
crosses in or out of the INSAT GEOSAR coverage area; and
|
|
b.
|
|
evaluating real beacon alerts detected by the LEOSAR system, and assessing if the
|
|
same alerts were detected by the INSAT GEOSAR system.
|
|
The technical tests were carried out in 2001 with the support of Australia by mounting a test
|
|
beacon on a moving ship from Australia to New Zealand. During this test beacon detection
|
|
was observed till 0 deg elevation angle with respect to INSAT-2B, and there was no signal
|
|
detected at -0.5 deg elevation angle. The detailed results were presented in JC-15 (INSAT-2B
|
|
Edge of Coverage Test, JC-15/9/5, June 2001, see Figures 3-1 and 3-2). In real operational
|
|
scenario, INSAT-3A detected number of beacons in Europe and Africa providing actual
|
|
coverage close to 0 deg elevation angle in western side of INSAT-3A foot-print. The number
|
|
of real alerts reported by AUMCC, which were detected by INSAT-3A confirming actual
|
|
coverage close to theoretical one in the eastern side of INSAT-3A foot-print.
|
|
Figure 3-1: Vessel's Actual Course of Sailing, between the Two Stars, GEOLUT Lost
|
|
|
|
3 - 8
|
|
|
|
Figure 3-2: INSAT-2B, Loss of Beacon Detection at 0 Elevation
|
|
3.8 C-1: Commissioning of the INSAT GEOLUT
|
|
The downlink antennas of the INSAT-3A satellite have directive beams that can be only
|
|
received in the Indian region. Currently, the only GEOLUT attached to the INSAT satellite is
|
|
located in Bangalore. Part of the INSAT GEOSAR performance evaluation plan includes the
|
|
verification of the compliance of INSAT GEOLUT with the performance specification
|
|
(C/S T.009).
|
|
Document C/S T.010 provides the detailed testing and reporting requirements for the
|
|
commissioning of the Cospas-Sarsat INSAT GEOLUT. The annexes of the documents define
|
|
the test data format requirements and the content and format of the commissioning report
|
|
which is to be submitted to the Cospas-Sarsat Secretariat.
|
|
Table 3.7 provides a summary of the Bangalore GEOLUT Commissioning Test results.
|
|
Detailed description and performance is available as part of the Bangalore GEOLUT
|
|
Commissioning Report provided separately.
|
|
|
|
3 - 9
|
|
|
|
Table 3.7: Summary of the GEOLUT Commissioning Test Results \*
|
|
Slno
|
|
Requirement
|
|
or Test
|
|
Result
|
|
Pass/ Fail
|
|
Method of
|
|
Compliance
|
|
Declaration/Verification or
|
|
Comments
|
|
|
|
Bit Rate
|
|
Tolerance
|
|
Check
|
|
Test - BR1
|
|
N/A
|
|
Pass
|
|
M
|
|
Both the Beacons
|
|
(2DDDF3B4145753D,
|
|
2DDDF3B4145753D)
|
|
were detected and sent to MCC.
|
|
|
|
Beacon
|
|
Message
|
|
Recovery
|
|
Test MR1
|
|
Beacon not
|
|
detected
|
|
Pass
|
|
M
|
|
Beacon (ADDC00000000008) was
|
|
suppressed as expected.
|
|
|
|
Beacon
|
|
Message
|
|
Recovery
|
|
Test MR2
|
|
Beacon not
|
|
detected
|
|
Pass
|
|
M
|
|
Beacon (2DDE0000938299A)
|
|
suppressed as expected.
|
|
|
|
Bit
|
|
Verification
|
|
Test BV1
|
|
Beacon
|
|
detected
|
|
Partial
|
|
Pass
|
|
M
|
|
One beacon (ADDC00000000000)
|
|
with no bit error was detected,
|
|
another beacon missed:
|
|
ADDC22000000000).
|
|
|
|
Bit
|
|
Verification
|
|
Test BV2
|
|
Beacon
|
|
detected
|
|
Pass
|
|
M
|
|
Beacon was detected and sent to
|
|
MCC (ADC21C348649240),
|
|
without error correcting in long
|
|
message, as expected.
|
|
|
|
Bit
|
|
Verification
|
|
Test BV3
|
|
Beacon
|
|
detected
|
|
Pass
|
|
M
|
|
Error bits corrected at bit 138, and
|
|
transmitted to MCC as required
|
|
(ADDD55555555554).
|
|
|
|
Beacon
|
|
Message
|
|
Validation
|
|
Test MV1
|
|
Beacon
|
|
Detected
|
|
Partial
|
|
Pass
|
|
M
|
|
Beacon detected
|
|
(2DDC0000004E534), verified and
|
|
found that bits 113-144 are not set
|
|
to "1" as required.
|
|
|
|
Beacon
|
|
Message
|
|
Processing
|
|
Test MP1
|
|
Beacon not
|
|
Detected
|
|
Partial
|
|
Pass
|
|
M
|
|
One beacon (2DDFFFFFDF81FE0)
|
|
was detected with default position,
|
|
and another one with updated
|
|
position was missed
|
|
(2DDFFFFF938299C).
|
|
|
|
Processing
|
|
Performance
|
|
Test PP1
|
|
100%
|
|
Pass
|
|
M
|
|
All 25 beacons detected within 5
|
|
minutes.
|
|
M-Measurement, D-Declaration, and V-Verification
|
|
* The results are preliminary. Formal commissioning of the GEOLUT is under review.
|
|
- END OF SECTION 3 -
|
|
|
|
3 - 10
|
|
|
|
page left blank
|
|
|
|
4 - 1
|
|
|
|
4.
|
|
CONCLUSIONS
|
|
The INSAT GEOSAR performance evaluation test results show that the INSAT GEOSAR
|
|
system reliably detects beacons with uplink EIRPs greater 32 dBm. Furthermore at the
|
|
33 dBm threshold the system also reliably provides confirmed complete beacon messages.
|
|
The ability to provide confirmed complete messages indicates that the INSAT GEOSAR
|
|
system will effectively provide MCCs with precise encoded location information when this
|
|
data is transmitted in location protocol beacons.
|
|
- END OF SECTION 4 -
|
|
|
|
4 - 2
|
|
|
|
page left blank
|
|
|
|
________________________________________________________
|
|
ANNEXES TO THE
|
|
COSPAS-SARSAT
|
|
INSAT GEOSAR PERFORMANCE
|
|
EVALUATION REPORT
|
|
_________________________________________________________
|
|
|
|
A - 1
|
|
|
|
ANNEX A
|
|
PROCESSING THRESHOLD AND SYSTEM MARGIN TEST RESULTS
|
|
Processing Threshold and System Margin Test Results Measured by Bangalore's GEOLUT
|
|
Table A-1: Analysed Results for Objective T-1
|
|
EIRP
|
|
from
|
|
simulator
|
|
(dBm)
|
|
Calculated C/No at
|
|
GEOLUT
|
|
(dBHz)
|
|
Number of
|
|
Beacon Events
|
|
Used (Valid
|
|
Msg Sample
|
|
Set)
|
|
Number of Beacon Events for which
|
|
Probability
|
|
of Valid
|
|
Message
|
|
Probability
|
|
of Valid
|
|
Message
|
|
within 5 Min
|
|
Valid Message
|
|
was Produced
|
|
Valid Message
|
|
was Produced
|
|
within 5 Min
|
|
28.0
|
|
31.8
|
|
|
|
|
|
0.02
|
|
0.02
|
|
29.0
|
|
32.8
|
|
|
|
|
|
0.20
|
|
0.00
|
|
30.0
|
|
33.7
|
|
|
|
|
|
0.84
|
|
0.38
|
|
31.0
|
|
34.7
|
|
|
|
|
|
0.74
|
|
0.20
|
|
32.0
|
|
35.7
|
|
|
|
|
|
0.98
|
|
0.74
|
|
33.0
|
|
36.7
|
|
|
|
|
|
1.00
|
|
0.94
|
|
34.0
|
|
37.6
|
|
|
|
|
|
1.00
|
|
0.90
|
|
35.0
|
|
38.6
|
|
|
|
|
|
1.00
|
|
1.00
|
|
36.0
|
|
39.6
|
|
|
|
|
|
1.00
|
|
0.98
|
|
37.0
|
|
40.6
|
|
|
|
|
|
1.00
|
|
0.98
|
|
EIRP
|
|
from
|
|
simulator
|
|
(dBm)
|
|
Number of
|
|
Beacon Events
|
|
Used
|
|
(Complete Msg
|
|
Sample Set)
|
|
Number of
|
|
Beacon Events
|
|
Used
|
|
(Confirmed
|
|
Complete Msg
|
|
Sample Set)
|
|
Number of Beacon
|
|
Events for which a
|
|
Complete Message
|
|
was Produced
|
|
Number of Beacon
|
|
Events for which a
|
|
Confirmed
|
|
Complete Message
|
|
was Produced
|
|
Probability of
|
|
Complete /
|
|
Confirmed
|
|
Complete Msg
|
|
28.0
|
|
|
|
|
|
0.02 / 0.02
|
|
29.0
|
|
|
|
|
|
0.20 / 0.20
|
|
30.0
|
|
|
|
|
|
0.84 / 0.84
|
|
31.0
|
|
|
|
|
|
0.74 / 0.74
|
|
32.0
|
|
|
|
|
|
0.98 / 0.98
|
|
33.0
|
|
|
|
|
|
1.00 / 1.00
|
|
34.0
|
|
|
|
|
|
1.00 / 1.00
|
|
35.0
|
|
|
|
|
|
1.00 / 1.00
|
|
36.0
|
|
|
|
|
|
1.00 / 1.00
|
|
37.0
|
|
|
|
|
|
1.00 / 1.00
|
|
|
|
A - 2
|
|
|
|
- END OF ANNEX A -
|
|
Figure A-1: Processing Threshold and System Margin Performance (T1)
|
|
Processing Threshold and System Margin
|
|
|
|
|
|
0.95
|
|
0.96
|
|
0.97
|
|
0.98
|
|
0.99
|
|
|
|
Probability of Valid Message
|
|
Processing Threshold (EIRP, dBm)
|
|
|
|
B - 1
|
|
|
|
ANNEX B
|
|
VALID MESSAGE PROCESSING PERFORMANCE
|
|
Valid Message Processing Performance Test Results Measured by Bangalore's GEOLUT
|
|
- END OF ANNEX B -
|
|
Figure B-1: Valid Message Processing Performance within 5 minutes (T1)
|
|
Valid Message Processing Performance
|
|
|
|
|
|
0.1
|
|
0.2
|
|
0.3
|
|
0.4
|
|
0.5
|
|
0.6
|
|
0.7
|
|
0.8
|
|
0.9
|
|
|
|
Probability of Valid Message within 5 Minutes
|
|
Processing Performance
|
|
(EIRP in dBm)
|
|
|
|
B - 2
|
|
|
|
page left blank
|
|
|
|
C - 1
|
|
|
|
ANNEX C
|
|
COMPLETE AND CONFIRMED COMPLETE MESSAGE
|
|
PERFORMANCE TEST RESULTS
|
|
Complete and Confirmed Complete Performance Test Results
|
|
Measured by Bangalore's GEOLUT
|
|
- END OF ANNEX C -
|
|
Figure C-1: Long Message Processing Performance (T1)
|
|
Long Message Processing Performance (Complete & Confirmed
|
|
Complete Messages Merged - having same probability)
|
|
|
|
|
|
0.1
|
|
0.2
|
|
0.3
|
|
0.4
|
|
0.5
|
|
0.6
|
|
0.7
|
|
0.8
|
|
0.9
|
|
|
|
Probability of Successful Message Processing
|
|
EIRP (dBm)
|
|
Complete Msg
|
|
Confirmed Msg
|
|
|
|
C - 2
|
|
|
|
page left blank
|
|
|
|
D - 1
|
|
|
|
ANNEX D
|
|
TIME TO PRODUCE VALID, COMPLETE AND
|
|
CONFIRMED COMPLETE MESSAGES TEST RESULTS
|
|
Time to Produce Valid, Complete and Confirmed Complete Message Test Results
|
|
Measured by Bangalore's GEOLUT
|
|
Table D-1:
|
|
Analysed Results for Objective T-2
|
|
EIRP
|
|
(dBm)
|
|
C/No
|
|
(dBHz
|
|
)
|
|
ATVM
|
|
(Sec)
|
|
Standard
|
|
Deviation
|
|
of ATVM
|
|
ATCM
|
|
(Sec)
|
|
Standard
|
|
Deviation of
|
|
ATCM
|
|
ATCCM
|
|
(Sec)
|
|
Standard
|
|
Deviation of
|
|
ATCCM
|
|
|
|
31.8
|
|
|
|
|
|
32.8
|
|
|
|
|
|
33.7
|
|
|
|
|
|
34.7
|
|
|
|
|
|
35.7
|
|
|
|
|
|
36.7
|
|
|
|
|
|
37.6
|
|
|
|
|
|
38.6
|
|
|
|
|
|
39.6
|
|
|
|
|
|
40.6
|
|
|
|
|
|
EIRP
|
|
(dBm)
|
|
C/No
|
|
(dBHz
|
|
)
|
|
95th Percentile
|
|
98th Percentile
|
|
Valid Msg
|
|
(Sec)
|
|
Complete
|
|
Msg (Sec)
|
|
Confirmed
|
|
Msg (Sec)
|
|
Valid Msg
|
|
(Sec)
|
|
Complete
|
|
Msg (Sec)
|
|
Confirmed
|
|
Msg (Sec)
|
|
|
|
31.8
|
|
|
|
|
|
32.8
|
|
|
|
|
|
33.7
|
|
|
|
|
|
34.7
|
|
|
|
|
|
35.7
|
|
|
|
|
|
36.7
|
|
|
|
|
|
37.6
|
|
|
|
|
|
38.6
|
|
|
|
|
|
39.6
|
|
|
|
|
|
40.6
|
|
|
|
|
|
D - 2
|
|
|
|
Figure D-1: Graphs Depicting Message Production Avg. Time (T2)
|
|
Average Time to Produce Valid, Complete & Confirmed
|
|
Complete Messages
|
|
|
|
|
|
Seconds After First Burst of Beacon Event
|
|
EIRP (dBm)
|
|
Valid Msg
|
|
Complete Msg
|
|
Confirmed Msg
|
|
95th Percentile (T2)
|
|
|
|
|
|
1000 1100
|
|
Time (Seconds)
|
|
EIRP (dBm)
|
|
Valid Msg
|
|
Complete Msg
|
|
Confirmed Msg
|
|
Figure D-2: Graphs Depicting Message Production Time - 95th Percentile (T2)
|
|
|
|
D - 3
|
|
|
|
- END OF ANNEX D -
|
|
Figure D-3: Graphs Depicting Message Production Time - 98th Percentile (T2)
|
|
98th Percentile (T2)
|
|
|
|
|
|
1000 1100
|
|
Time (Seconds)
|
|
EIRP (dBm)
|
|
Valid Msg
|
|
Complete Msg
|
|
Confirmed Msg
|
|
|
|
D - 4
|
|
|
|
page left blank
|
|
|
|
E - 1
|
|
|
|
ANNEX E
|
|
FREQUENCY MEASUREMENT ACCURACY TEST RESULTS
|
|
Frequency Measurement Accuracy Test Results Measured by Bangalore's GEOLUT
|
|
Table E-1:
|
|
Analysed Results for Objective T-3
|
|
EIRP
|
|
(dBm)
|
|
Calculated C/No
|
|
at GEOLUT
|
|
(dBHz)
|
|
Avg Freq Measurement Error
|
|
(Hz rounded to 1 decimal place)
|
|
Std Deviation of Error
|
|
(Hz)
|
|
|
|
31.8
|
|
-37.22
|
|
N.A. (1 data point)
|
|
|
|
32.8
|
|
-16.77
|
|
0.71
|
|
|
|
33.7
|
|
-50.57
|
|
0.15
|
|
|
|
34.7
|
|
-50.89
|
|
0.22
|
|
|
|
35.7
|
|
21.63
|
|
0.71
|
|
|
|
36.7
|
|
13.6
|
|
0.30
|
|
|
|
37.6
|
|
5.53
|
|
0.24
|
|
|
|
38.6
|
|
-1.63
|
|
0.16
|
|
|
|
39.6
|
|
-49.15
|
|
0.15
|
|
|
|
40.6
|
|
-47.10
|
|
0.13
|
|
Figure E-1: Average Frequency Measurement Accuracy Performance (T3)
|
|
Frequency Measurement Accuracy Performance
|
|
|
|
|
|
EIRP (dBm)
|
|
Avg. Freq Measurement Error
|
|
(Hz)
|
|
|
|
E - 2
|
|
|
|
- END OF ANNEX E -
|
|
Figure E-2: Average Frequency Measurement Standard Deviation
|
|
Accuracy Performance (T3)
|
|
Frequency Measurement (Standard Deviation) Accuracy
|
|
Performance
|
|
|
|
0.2
|
|
0.4
|
|
0.6
|
|
0.8
|
|
|
|
|
|
EIRP (dBm)
|
|
Std. Dev. Measurement
|
|
Error (Hz)
|
|
|
|
F - 1
|
|
|
|
ANNEX F
|
|
CAPACITY TEST RESULTS
|
|
Capacity Test Results Measured by Bangalore's GEOLUT
|
|
Table F-1: Capacity Statistics for Test Objective T-4
|
|
Channel: 406.06300 MHz
|
|
# of Active
|
|
Bcn Events
|
|
% Valid Msg within
|
|
5 Min
|
|
% Valid Msg
|
|
within10 Min
|
|
% Valid Msg within
|
|
15 Min
|
|
% Confirmed Complete
|
|
Msg within 15 Min
|
|
\*10
|
|
>95
|
|
>95
|
|
>95
|
|
>95
|
|
|
|
|
|
* This test (with 10 beacons) was not carried out due to shortage of time. By extrapolating the
|
|
curve plotted for 15, 20 and 25 beacons, the results indicate that for beacon populations with
|
|
uplink EIRP values exceeding 37 dBm, the capacity would exceed detection of 10
|
|
simultaneous beacons by INSAT GEOSAR system.
|
|
- END OF ANNEX F -
|
|
- END OF DOCUMENT -
|
|
Figure F-1: INSAT GEOSAR Capacity (T4)
|
|
Graph Depcting INSAT GEOSAR Capacity
|
|
0.6
|
|
0.7
|
|
0.8
|
|
0.9
|
|
|
|
|
|
No. of Simultaneously Active Beacons per Channel
|
|
Probability
|
|
Valid Msg (5 Min)
|
|
Valid Msg (10 Min)
|
|
Valid Msg (15 Min)
|
|
Confirm Msg (15 Min)
|
|
|
|
F - 2
|
|
|
|
page left blank
|
|
|
|
Cospas-Sarsat Secretariat
|
|
1250 Rene-Levesque Blvd. West, Suite 4215, Montreal (Quebec) H3B 4W8 Canada
|
|
Telephone: +1 514 500 7999
|
|
Fax: +1 514 500 7996
|
|
Email: mail@cospas-sarsat.int
|
|
Website: http://www.cospas-sarsat.int |