Stochastic simulation of delay-Doppler maps for GNSS-R

A new approach for simulation of delay-Doppler maps for ocean global navigation satellite system reflectometry is presented. The simulator is based on a stochastic forward scattering model for generation of realizations of the sea surface reflected signal and allows a flexible definition of system and environmental parameters. The signal scattered from a delay Doppler cell is modelled as the coherent random sum of a large number of components from specular points; the sum converges to a compound-Gaussian random variable when the mean number of points is sufficiently large. In the proposed simulation process, the discretization of the DDM arises from a natural sampling of the delay-Doppler domain rather than on sampling the ocean surface. Instantaneous DDMs are simulated and consistency with the theoretical model is verified.