Developments in GNSS-Reflectometry from the SGR-ReSI in Orbit on TechDemoSat-1

The SGR-ReSI (Space GNSS Receiver – Remote Sensing Instrument) is remote sensing payload compatible with small satellites. GNSS Reflectometry makes use of reflected GNSS signals as if radar transmissions, and as a result, only the GNSS receiver is required onboard the satellite to implement a bi-static radar system. The SGR-ReSI can log unprocessed data from the RF downconverter for later processing, but most significantly can process the reflections on-board into Delay Doppler Maps (DDMs). The first flight of the ReSI is on the UK TechDemoSat-1 (TDS-1) satellite, launched in July 2014. The DDMs are downloaded, extracted and processed to synchronise with the satellite’s GPS position and other metadata. Surrey’s partner, the National Oceanographic Centre provided algorithms that recover the ocean roughness and wind speed (Level 2 data) from the DDMs