Decoding Lunar Flashlight cubesat telemetry using GNU Radio.
GNU Radio is a powerful tool for decoding telemetry from satellites, as demonstrated by Daniel Estévez’s work on decoding telemetry from the Lunar Flashlight cubesat. The recording was made from a 20-meter antenna at 8.4 GHz and lasted for 3 minutes. The modulation used was PCM/PM/bi-phase-L with a nominal speed of 48,000 baud, though Daniel measured it to be 48,077. The encoding used was the CCSDS standard, and the frequency jumped midway through the recording, likely due to the satellite correcting its frequency to lock to an uplink carrier from a ground station.
To interpret the data, Daniel used Jupyter and made some assumptions about the format of the telemetry. He also tried the same trick for Voyager I. For those interested in trying GNU Radio, even without any radio hardware, there is an introduction available.
GNU Radio is a powerful and versatile tool that can be used to decode telemetry from satellites. It is not difficult to use, as evidenced by Daniel Estévez’s work on the Lunar Flashlight cubesat. He used PCM/PM/bi-phase-L modulation with a speed of 48,077 baud and the CCSDS standard encoding. By using Jupyter and making some assumptions, he was able to interpret the data. This same trick can be used for Voyager I. For those interested in trying GNU Radio, there is an introduction available.
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