If you’re looking for practical examples of using GNU Radio, check out: [Daniel Estévez’s] Work on deciphering captured telemetry From Luna Flashlight CubesatCubesat is I’m worried, but the data in question was recorded from the day after the launch. I’m not sure what it takes to eavesdrop live, but the 3 minute recording is from a he 8.4 GHz he 20 meter antenna.
of GNU Radio’s flow graph It’s not as bad as it sounds, thanks to the careful reuse of blocks from other projects to do some decoding. The modulation method is PCM/PM/bi-phase L. The nominal speed is 48,000 baud, [Daniel] The measured value was 48,077.
Spacecraft telemetry is often CCSDS (Space Data Systems Advisory Committee) standard, and the encoding matches the standard. One oddity is that halfway through the recording, the carrier frequency exceeds 120 kHz. [Daniel] speculate that the satellite had modified its frequency to lock onto the uplink carrier from the ground station.
Once the data is unpacked, we need to interpret it. [Daniel] It does a good job using Jupyter. He doesn’t know the full form of all telemetry, but he makes some assumptions that seem plausible. I have to wonder how the analysis results compare to JPL’s official ground stations.
The last time I checked in with Daniel he did the same trick Voyager IIf you want to try out GNU Radio, even if you don’t have radio hardware, check out our site. Foreword.
