In my previous post I talked about the FEC used by the SMOG-P and ATL-1. In there, I reverse-engineered the long frames transmitted by SMOG-P and found that they use the AO-40 FEC protocol.
After publishing that post I started reverse-engineering the short frames. Meanwhile, Peter Horvath pointed me to a Github repository containing an implementation of the FEC used for short frames and long frames. I hadn’t seen that repository before (it’s not easy to search for SMOG-P or ATL-1 in Google, as many unrelated results come up). Indeed this repository contains the source of a FEC decoder for the short frames, so there is no need to reverse-engineer it.
Timur Kristóf, the author of that repository, says that the team plans to release the source for the decoder, but that they are currently very busy with the early operations of the satellites. This is very good news.
I have studied the code in the Github repository and included a decoder for the short FEC frames in gr-satellites.Continue reading “SMOG-P short codes”