Listening To A Flashlight — Lunar Flashlight

Should you’ve been on the lookout for a sensible instance of utilizing GNU Radio, it’s best to try [Daniel Estévez’s] work on decoding telemetry captured from the Lunar Flashlight cubesat. The cubesat is having some bother, however the knowledge in query was a recording from the day after launch. We aren’t certain what it might take to snoop on it reside, however the 3-minute recording is from a 20-meter antenna at 8.4 GHz.

The flowgraph for GNU Radio isn’t as unhealthy as you may suppose, due to some even handed reuse of blocks from different tasks to do among the decoding. The modulation is PCM/PM/bi-phase-L. Nominally, the pace is meant to be 48,000 baud, however [Daniel] measured 48,077.

Spacecraft telemetry usually makes use of the CCSDS (Consultative Committee for Area Information Techniques) commonplace, and the encoding matches the usual. One oddity is that halfway by means of the recording, the service frequency jumps over 120 kHz. [Daniel] speculates that the satellite tv for pc was correcting its frequency to lock to an uplink service from a floor station.

As soon as the information is unpacked, you need to interpret it, and [Daniel] does an excellent job utilizing Jupyter. He doesn’t know the entire format of all of the telemetry, however he makes some assumptions that appear sound. We now have to marvel how the analytics evaluate with JPL’s official floor station.

The final time we checked in with Daniel, he did the identical trick for Voyager I. If you wish to strive GNU Radio — even in case you don’t have any radio {hardware} — try our introduction.


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