A comparison of EM scattering results and radar sea clutter

The characteristics of radar sea clutter have been studied for many years, mostly to develop empirical models for the average back-scattered energy, the amplitude statistics and the Doppler spectrum. These models have been successful at describing the variations of behaviour with sea-state and viewing geometry, but have not been able to establish the link between specific features on the sea surface and the radar backscatter. This paper describes a programme of work where carefully controlled radar and surface measurements in a wavetank are compared with real radar sea clutter and electromagnetic scattering calculations. The results show that a direct link can be made, thus allowing a causal relationship to be established between specific features on the sea surface and remotely gathered radar sea clutter. The EM scattering calculations provide the means for the results to be extended over a wide range of radar frequencies, resolutions, and grazing angles. Also the effect of modifying the sea surface wave spectrum may be calculated.