High grazing angle X-band sea clutter distributions

This paper investigates the statistical properties of sea clutter at grazing angles higher than traditionally used for airborne maritime radar surveillance, i.e. 10° – 45°. Specifically, we study the spatial distribution of X-band, high resolution and high grazing angle polarimetric sea clutter data. We found that among the VV, HV, and HH polarisations, the VV data is least spiky and the K distribution usually provides a good fit. The HH data is spikiest and its distribution exhibits a sudden departure from the K distribution in the upper tail region, which usually requires the KA or similar distributions to achieve a better fit. Due to drawbacks of the KA distribution, this paper proposes a combination of two K distributions to fit the distribution of sea clutter with spikes. Referred to as the KK distribution model, it is found to provide the best overall fit.