A novel linear-quadratic technique for coherent radar detection in mixed clutter environment

This paper introduces a sub-optimum procedure for the detection of a signal of known form in the presence of non Gaussian disturbance, that is assumed to be a mixture of coherent K-distributed and Gaussian distributed clutter sources. As a comparison, the optimum Neymann-Pearson (NP) strategy to detect the a priori known signal against the above mentioned disturbance is also presented. The optimum NP detection scheme is not simple to implement: it involves a heavy numerical integration with respect to the texture variable of the K distribution. Besides it strongly depends on the parameters v and ¿ of the texture distribution, so no predetermined threshold can be assigned to achieve a given probability of false alarm if they are unknown. Our idea is to estimate the texture variable, or rather the local power in the cell under test, and to use this estimate in the likelihood ratio. The resulting detection strategy is linear-quadratic and clutter distribution free. Moreover the performance is almost equal to that of the optimum receiver.