Application of a New Distribution to High Grazing Angle Sea-Clutter

Many studies show that the sea clutter obeys the K distribution. With the continuous improvement of the radar resolution and the increase of the grazing angle, the distribution of sea clutter gradually deviates from the K distribution. Although good fitting results can be obtained through the more complicated sea clutter models such as KK distribution, KA distribution, K+Rayleigh distribution and so on, the computational efficiency of the detection algorithm is reduced obviously. For computational complexities are caused by large number of parameter estimations and non-closed expression. A hybrid sea-clutter distribution (KR distribution) with closed-form expression for high-resolution and high grazing angle situation is proposed, which fits the measured data. The method of parameter estimation for KR distribution is given, that is, the geometric segmentation parameter estimation method based on path gain. The results show that the fitting effect of KR distribution is better than both of K distribution and Rayleigh distribution under the conditions of high resolution and large grazing angle. The fitting effect will be better as the grazing angle increases. The parameter estimation method of geometric segmentation based on path gain can find the fitting parameters accurately.