Funded by ESA, CoSMOS-OS 2007 comprised three flights on the TKK's Skyvan, along estuaries of the Finish coast to capture the gradient in the sea surface salinity using two L-band radiometers: TKK's HUT-2D (interferometric) and DTU's EMIRAD. Together with the flights, conducted after sunset to avoid contamination of the radiometric measurements due to the L-band emissions of the Sun, the campaign was complemented with in-situ measurements of the sea surface salinity, taken from a boat.
The ICE/IEEC-CSIC contributed with its GOLD-RTR instrument, flight operation and data analysis to provide estimates of the sea surface roughness sensitive to L-band signals, required to correct its effects in the radiometric retrievals. The additional goal of the project was to use the GNSS-R signals to perform altimetry. For doing so, the project was complemented with measurements of the instantaneous sea surface level by means of GPS buoys deployed from a boat collocated with and simultaneous to the flights.