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B-4.3 Telemetry Synchronization and Extraction

Figure B-4 illustrates the processing flow within the Sync/Extract Telemetry process. Subprocesses include Frame/Packet Synchronization (1), Format ID and Embedded Determination (2), and Extract Raw Measurand (3).

Figure B-4. Sync/Extract Telemetry data flow diagram.

Frame/Packet Synchronization - This process decrypts the PCM telemetry, performs required polarity inversion, ingests decrypted serial PCM and IRIG time, and performs bit and/or frame synchronization. Time-Tagged Mainframes, as well as bit synchronization status, are output for further processing and are also archived as Raw Data. Archived Raw Data can be recalled for processing. Synchronization pattern, synchronization strategy (e.g., bit errors, synchronization aperture)and wavetrain characteristics (e.g., frame length) are required information from Telemetry IB.

Format ID and Embedded Determination - Depending on which word is being extracted (format id parameter), this function returns format information (i.e., word length, measurand id) to Extract Raw Measurand.

Extract Raw Measurand - Depending on the synchronization strategy (search, lock, verify) and on the active format information provided by Format ID and Embedded Determination, this process extracts and identifies a raw measurand. This includes measurands for time and both frame/packet synchronization and decom status. Embedded words are returned to Frame/Packet Synchronization for subframe or subsubframe decommutations.

Three outputs are shown. The 3-15 Mbps output consists of raw mission/sensor measurands which will be passed to the external Mission Data Processing function. The 225 bps to 384 Kbps output consists of raw SOH measurands and tags. The 384 Kbps output consists of raw embedded SOH measurands and tags that have been extracted from the 1-5 Mbps mission/sensor stream.