Ryan Malloy
0ee7ff0ad7
Complete signal processing pipeline from complex baseband to decoded PCM telemetry, verified against the 1965 NAA Study Guide (A-624): Core demod (Phase 1): - PM demodulator with carrier PLL recovery - 1.024 MHz subcarrier extractor (bandpass + downconvert) - BPSK demodulator with Costas loop + symbol sync - Convenience hier_block2 combining subcarrier + BPSK PCM frame processing (Phase 2): - 32-bit frame sync with Hamming distance correlator - SEARCH/VERIFY/LOCKED state machine, complement-on-odd handling - Frame demultiplexer (128-word, A/D voltage scaling) - AGC downlink decoder (15-bit word reassembly from DNTM1/DNTM2) Voice and analog (Phase 3): - 1.25 MHz FM voice subcarrier demod to 8 kHz audio - SCO demodulator for 9 analog sensor channels (14.5-165 kHz) Virtual AGC integration (Phase 4): - TCP bridge client with auto-reconnect and channel filtering - DSKY uplink encoder (VERB/NOUN/DATA command sequences) Top-level receiver (Phase 5): - usb_downlink_receiver hier_block2: one block, complex in, PDUs out - 14 GRC block YAML definitions for GNU Radio Companion - Example scripts for signal analysis and full-chain demo Infrastructure: - constants.py with all timing/frequency/frame parameters - protocol.py for sync word + AGC packet encode/decode - Synthetic USB signal generator for testing - 222 tests passing, ruff lint clean
49 lines
1.1 KiB
YAML
49 lines
1.1 KiB
YAML
id: apollo_downlink_decoder
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label: Apollo Downlink Decoder
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category: '[Apollo USB]'
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flags: [python]
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parameters:
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- id: buffer_size
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label: Buffer Size (words)
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dtype: int
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default: '400'
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inputs:
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- label: agc_data
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domain: message
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outputs:
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- label: downlink
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domain: message
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templates:
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imports: from apollo import downlink_decoder
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make: apollo.downlink_decoder.downlink_decoder(buffer_size=${buffer_size})
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documentation: |-
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Apollo AGC Downlink Decoder
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Reassembles 15-bit AGC words from channel 34/35 byte pairs and
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interprets downlink list headers to identify mission-phase telemetry.
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The AGC sends telemetry snapshots in "downlink lists" whose format
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depends on mission phase:
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ID 0: CM Powered Flight
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ID 1: LM Orbital Maneuvers
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ID 2: CM Coast/Alignment
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ID 3: LM Coast/Alignment
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ID 7: LM Descent/Ascent
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ID 8: LM Lunar Surface Alignment
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ID 9: CM Entry Update
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AGC word reassembly:
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DNTM1 (ch 34): bits 14-8 (high 7 bits)
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DNTM2 (ch 35): bits 7-0 (low 8 bits)
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Combined: 15-bit word (0-32767)
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Parameters:
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buffer_size: Number of 15-bit words per downlink buffer (default 400)
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file_format: 1
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