Shape-Parameter-Dependent Coherent Radar Target Detection in K-distributed Clutter

In this paper, shape-parameter-dependent matched filter (MF) detectors are proposed for moving target detection in K-distributed clutter, which are specified by a single parameter alpha is an element of [0, 1], the alpha-MF detectors for short. The alpha-MF detectors include the MF and normalized matched filter (NMF) detectors as special examples with alpha = 0 and 1. The parameter alpha can be chosen to match clutter characteristics. An empirical formula is given that the optimal parameter alpha equals the number of integrated pulses divided by it plus the shape parameter of K-distributed clutter. It is proved that the alpha-MF detectors are constant false alarm rate (CFAR) with respect to the scale parameter, clutter covariance matrix, and Doppler steering vector. The properties of adaptive alpha-MF (alpha-AMF) detectors are discussed. For K-distributed clutter, the optimal alpha-MF detectors are superior to the MF and NMF detectors and are comparable with the optimal K-distributed detectors (OKDs) of high computational cost. Finally, real high-resolution sea clutter data are available to verify the proposed detectors. The optimal alpha-AMF detectors under K-distributed clutter model are competitive in performance with the adaptive generalized likelihood ratio test linear threshold detectors (GLRT-LTDs) that are optimal for the compound-Gaussian clutter with the inverse Gamma texture.