Brussels / 3 & 4 February 2018


Claim Space, the Libre Way, using SDRs

So many things happened from the FOSDEM 2017 in the SatNOGS project. The successful deployment and data reception of the UPSat satellite, high power amateur rocket launches and realtime telemetry decoding, automatic decoding of LEO satellite signals from our crowd-sourced network of ground stations are some of the milestones achieved. And all these with the help of Software Defined Radios!

In this talk, we present briefly the UPSat and the High Power Rocketry project and then the version 3 of the SatNOGS project. In the new version we have developed several decoders that operate in realtime during a LEO satellite pass. Combined with the SatNOGS rotator that tries to point as accurate as possible to the satellite trajectory, the decoder searches for transmitted frames. The successfully decoded frames are then uploaded automatically on the SatNOGS database for visualization and further analysis.

Currently, SatNOGS project incorporates decoders for many popular in LEO satellite missions transmission schemes such as AFSK1200, APRS1200, (G)FSK9600, APRS9600, APT, DUV, CW, LRPT using the GNU-Radio toolkit. In addition, decoders for APT and LRPT are producing on the fly the weather images transmitted by the corresponding meteorological satellites. For the most interesting of the available decoders, we present the design and the implementation details among with a live decoding demo from a IQ captured observation.

All of the available decoders are running in realtime on the RPi3 platform. To achieve this, several design decisions were made (RF performance vs realtime operation) and we discuss some of them.


Photo of Manolis Surligas Manolis Surligas