Simulating GNSS-R delay-doppler map of oil slicked sea surfaces under general scenarios

Abstract

Presently, the simulated Delay Doppler Maps (DDMs) of oil slicked sea are limited to simplified scenarios which have the elevation angle of 90° (nadir reflection). In this paper, the detailed simulation process to generate GNSS-R DDMs of oil slicked sea surfaces under general scenarios is presented. The DDM of oil slicked sea surface under general scenarios are generated by combining the mean-square slope model for oil slicked/clean surfaces and the GNSS-R Zavorotny-Voronovich (Z-V) scattering model. The coordinate system transformation appropriate for general-elevation-angle scenarios are also incorporated. To validate the proposed approach, a comparison is made between the DDMs of a simplified scenario and a general scenario, which are generated based on the oil slick distribution of the Deepwater Horizon oil spill accident. Theoretical analysis reveals that oil slick may be detected within a 100 km radius coverage area around the specular point for a GNSS-R receiver under the general scenario with elevation angles of 72°.