gr-satellites¶
Decoders for the telemetry of hundreds of amateur satellites
- Version recorded: 5.5.0
- Categories:
satellite-decoding,sdr-toolkits - Upstream: https://github.com/daniestevez/gr-satellites
- Needs first:
gnuradio
What it does¶
A GNU Radio out-of-tree module carrying decoders for a very large number of amateur and research satellites: the modulation, the framing, the forward error correction and the telemetry format for each, plus the generic building blocks -- AX.25, CCSDS, several FEC schemes -- to write a decoder for one it does not know.
Why you would want it¶
Receiving a satellite is easy and understanding it is not. Every spacecraft has its own framing and its own telemetry layout, and this is the accumulated work of decoding them. It turns a recording of a pass into battery voltages and temperatures, which is what makes satellite listening a hobby rather than a demonstration.
Before it will work¶
An SDR and an antenna suited to the band -- most amateur satellites are on VHF and UHF. Doppler correction, which means knowing when the pass is and tracking it; gpredict feeding a tuning offset is the usual arrangement.
How it installs¶
- apt:
gr-satellites
Known problems¶
Satellites die, and a decoder for a spacecraft that has re-entered will never produce anything -- check the satellite is alive before debugging the decode chain. As an out-of-tree module it is compiled against a specific GNU Radio version, which matters on Mint 22.3 where GNU Radio is a minor release behind the other targets. Doppler shift on UHF is several kHz across a pass and an uncorrected receiver loses lock partway through.
Keeping it current¶
- probe: apt policy
- strategy: apt_upgrade
Where to get help with the software itself¶
Daniel Estevez, EA4GPZ. GitHub issues, and the documentation is genuinely good on the theory as well as the software.