Application of the Pareto Plus Noise Distribution to Medium Grazing Angle Sea-Clutter

Robust maritime surveillance with radar requires an accurate description of the backscatter from the sea. The probability distribution of the backscatter is commonly used to determine the threshold for separating targets from clutter. Analysis of data collected at medium grazing angles, between 15° and 45°, by the Defence Science Technology Organisation (DSTO) Ingara fully polarimetric X-band radar has shown that the Pareto distribution is extremely useful as it both captures the high-magnitude components of the sea-clutter and allows significantly simpler optimal and suboptimal detectors to be designed. To further enhance the usefulness of this distribution, this paper presents a multilook formulation which accounts for the thermal noise in the radar. A number of techniques for evaluating the distribution are then presented, including a numerical integration scheme and a number of approximations, which retain the original form of the Pareto distribution.