In this video from the 28C3 Conference in Berlin, Sylvain Munaut describes the latest member of the Osmocom-family projects, osmo-gmr. This project focuses on the GMR-1 (GEO Mobile Radio) air interface used in some satellite Phones. Sylvain discusses the GMR protocol, the Thuraya network that uses this protocol in the Eurasian/African and Australian continents and finally details how you can capture samples and process them for analysis using osmo-gmr.
The PDF of the slides from this talk can be downloaded here. Read the project details and download code from the osmocom-gmr website.