Global Navigation Satellite System-Reflectometry (GNSS-R) from the UK-DMC Satellite for Remote Sensing of the Ocean Surface

In this paper we analyse the GPS signals reflected by the surface of the ocean to retrieve information about the sea surface roughness, expressed in statistical terms by means of the sea surface Mean Square Slopes (MSS). Particularly, we perform Delay-Doppler mapping of real scattered GPS signals from the Surrey Satellite Technolody Ltd UK-DMC mission, and we simulate Delay-Doppler Maps (DDMs) using the Zavorotny-Voronovich model of the GPS power scattered from the ocean surface, as a function of the geometrical properties of the transmitter and receiver, as well as statistical properties of the scattering surface. Subsequently, we fit simulated DDMs to the measured ones, to retrieve the optimal MSS of the scattering surface, and we compare GPS-derived MSS with theoretical and in situ MSS, calculated using the Elfouhaily et al. wave spectrum and co-located buoy spectra of the National Data Buoy Center (NDBC).