A compound representation of high resolution sea clutter

Measurements of sea clutter at low grazing angles using high resolution radar show that the probability density function, p(x), of envelope detected clutter is not Rayleigh. Based on time averaged sea clutter recordings, a compound form of p(x) is proposed leading to the K distribution for the overall p(x). This model is then used to explain both the non Rayleigh nature of the clutter and also the correlation properties for fixed frequency and frequency agile radar returns. Illustrations are given of applications to signal processing performance calculations along with some results for a fixed threshold.