This letter describes a simple model for the backscattered signal received from the ocean surface by a horizontal-polarization marine radar operating at low grazing angles, including the effects of the logarithmic amplifiers conventionally used in these radars. Shadowing is accounted for via geometric optics. The range dependence of the mean radar signal predicted by this model compares well with that observed in two marine radar data sets collected under different environmental conditions. The model also indicates that the radar signal modulation (the deviation from the mean normalized by the mean) is proportional to the radial component of the surface slope in unshadowed regions. This suggests the possibility of direct quantitative wave observations using marine radar modulation data, without the need for calibration.

This paper describes a method of processing marine radar signals for the purpose of generating phase-resolved surface elevation maps as well as statistical measures of ocean surface wave fields. The method is well suited to the processing of data collected by marine radars because it allows for the incorporation of effects dependent on the radar look direction relative to the propagation direction of ocean waves. Applications to Doppler radar and backscattered power measurements are described, and example results are presented using simulated radar data.

Marine radars have proven to be useful for measuring ocean waves, but the accuracy of the measurements is limited by several factors including the look-angle dependence of the radar signals as well as noise in the radar data. The look-angle dependence introduces a systematic error or bias in the measurements, and noise causes a random error. This paper describes a method of combining data from multiple radar frames that is optimal in the sense of minimizing the error for a set of biased measurements with random additive noise. The results are shown experimentally to increase the correlation of the radar estimates with buoy measurements.