Gps Signal Scattering from Sea Surface: Comparison between Experimental Data and Theoretical Model

Global Positioning System (GPS) signals reflected from the ocean surface have potential use for various remote sensing purposes. Some possibilities are measurements of surface roughness characteristics from which wave height, wind speed and direction could be determined. For this paper, GPS reflected signal measurements taken from aircraft are used to explore the possibility of determining wind speed. To interpret the GPS data, a theoretical model has been developed which describes the power of the reflected GPS signals for different time delays as a function of geometrical and environmental parameters. The results indicate a good agreement between the measured and the modeled normalized signal power waveforms even during rapidly changing surface wind conditions. The inferred wind speed, obtained by comparing actual and modeled waveforms, shows good agreement (within 2 m/s) with data obtained from a nearby buoy.