After running several observations, I noticed that DUV (Data Under Voice) telemetry was being decoded, but not presented in human form. I was curious and posted questions under my [observation] (Observation 150869: FOX-1A (40967) - FoxTelem?) of Fox1-A. The existing DUV decode showed me a lot of hexadecimal data, but no way to see it in human readable form. What does it all mean???
@n5fxh Francois-Xavier showed me how to download the ogg audio, convert it to a .wav file using sox and import it into FoxTelem to see everything. I repeated his instructions and figured it out.
I searched the Forum. It sounds like a pretty common thing: We’ve captured the audio file and sometimes there’s a decoder for the data, but not a lot of tools to see esp. telemetry in human readable form.
I did not want to lose how to do the decode and see it buried the discussion about the observation I made. If there’s an initial consensus, I will start adding a section called “Decode Telemetry and Packets” under Operate as my contribution back into a very nice system.
Is there a list of decoders provided by SatNOGS? E.g. I can’t get CW to demodulate anything. It gives the illusion as if its working on something.
After I try all of the included demodulators, I’m going to do a search and document those external packages that can be used in conjunction with the SatNOGS client, capturing how it’s done.
@WA4OSH – the closest thing I know of to a list of decoders is this directory in the gr-satnogs repo, which has the GNU Radio flowgraphs for the out-of-tree module. You can see that there are files for FOX telemetry, Morse, AX25 and so on. However, maybe someone else from the project can give a better answer? (/cc @fredy / @pierros)
CW decoding in particular is a work in progress; you can probably get the latest status by asking in Matrix/IRC, but I have the impression it’s changing quickly.
Here’s my discoveries for today while still excited to write it up
Looking at the ax.25 stuff - just discovered direwolf and have this procedure for AFSK1K2 like 42707 - X-CUBESAT - process the audio and decode to a text file in a single line:
Thanks for adding this to the wiki!! If someone wanted to convert my post into the wiki its still relevant on decoding in windows: Windows manual decoding howto
Our future plans are to roll all of this data into db.satnogs.org (where we already collect millions of frames through SiDS clients). Each satellite that we have telemetry decoding information for would then have a dashboard that visualizes all of the decoded data. We had a rough framework for this before adopting SiDS and haven’t fixed the dashboards since (I think we need to take a fresh approach to this).
At any rate, I wanted to point out that someday we won’t need to manually decode all of these. But for now I’ve got no ETA on the automation there.
IMHO, go for it.
