CFAR signal detection in nonhomogeneous Weibull clutter and interference

Abstract

Constant false alarm rate (CFAR) radar detectors designed to operate in Rayleigh distributed clutter do not generally perform satisfactorily in the presence of non-Rayleigh clutter due to their operating in significantly deviated clutter environments and also due to their inability to maintain CFAR in non-Rayleigh clutter. Data collected by high-resolution radars have confirmed the non-Rayleigh nature of certain land and sea clutter, often described by multi-parameter log-normal, Weibull or K-statistic models. In this paper, we investigate two CFAR detectors operating in nonhomogeneous Weibull clutter and multi-target interference. First, estimates of the unknown Weibull clutter parameters are employed to obtain a CFAR detector other than the log-t detector for Weibull clutter. Instead, it is shown that there is a one-to-one correspondence between the log-t detector and the proposed alternative, thus giving statistical justification for the use of the log-t detector in Weibull clutter. Performance characteristics of the log-t detector are then presented in homogeneous as well as nonhomogeneous Weibull clutter and multi-target environment, and detailed comparisons are made.