Variation of the Shape Parameter of K-Distribution for Sea Clutter with the Spatial Correlation of Sea Surface

In this study, the physical relationship between the shape parameter. of the K-distribution and the spatial correlation of a sea clutter signal received with a radar is demonstrated through simulation results. The spikiness of the sea clutter is well modeled by the shape parameter. of the K-distribution. According to a well-known empirical formula, the shape parameter. changes with the radar resolution based on a constant power-law relation. However, as with most empirical findings, this finding is valid only for the environmental conditions under which the formula was developed. In other words, the existing power-law models for the shape parameter of the K-distribution for sea clutter do not consider the relative ratio of the cross-range resolution R-c to the spatial decorrelation length R-dec of the sea surface. Our study investigates this relation using statistical simulations based on the principle of superposition for backscattered signals that represent sea clutter within a resolved area on the sea surface. This study shows that the constant factor a in the power-law relation must be modified to a function of the ratio R-c/R-dec. The findings of this study will be useful for the evaluation of detection performance in designing radar systems operating in the maritime environment.