Coherent Detection of Weak Moving Targets in Compound-Gaussian Clutter Using Nonlinear Preprocessing System: Performance Measure and Implementation

In this article, we focus on the design of coherent detectors in compound-Gaussian clutter using a nonlinear preprocessing system followed by the matched filter (MF). First, to evaluate the effectiveness of the preprocessing system, the signal-to-clutter ratio (SCR) gain of preprocessing system is proposed as its performance metric. It is proven that the upper bound of SCR gain is greater than unity for compound-Gaussian clutter, indicating that an appropriate preprocessing system can improve detection performance. Then the suprathreshold stochastic resonance (SSR) system composed of a parallel array of quantizers is introduced, which is an effective and easy-to-implement suboptimal preprocessing system. In compound-Gaussian clutter, a method for determining parameters of quantizer noise, which is purposely injected in the SSR system, is proposed. Finally, the performance improvement of the SSR preprocessing system for weak target in compound-Gaussian clutter is illustrated using both simulated clutter and real sea clutter data. Experiment results show that the proposed method can be applied to detect weak moving targets in sea clutter.