Variability index constant false alarm rate for marine target detection

Paper discusses and evaluates the application of Variability Index Constant False Alarm Rate (VI-CFAR) in radar signal processing for detection of marine targets. Work has been published in past for evaluation of VI-CFAR for Sonar Targets [1], however no work is published to the knowledge of authors of this paper for evaluation of VI-CFAR for Marine Targets by experimental sea trials. Marine environment is often filled with inhomogeneities such as sea clutter, reverberation edges and multiple targets. “Constant False Alarm Rate” (CFAR) processors are implemented in signal processing to generate adaptive threshold for detecting targets out of nonhomogeneous environment as well as maintain constant false alarm. Variability Index CFAR processor adopts dynamically among Greatest-Of CFAR (GO-CFAR), Cell Averaging CFAR (CA-CFAR) and Smallest-Of CFAR (SO-CFAR) based on target background. Estimation of target background is performed based on values of two statistic namely Variability Index (VI) and Mean Ratio (MR). Based on statistics, the VI-CFAR processor dynamically generates adaptive threshold as per background estimation. Comparison analysis of VI-CFAR against GO-CFAR, CA-CFAR and SO-CFAR for marine target detection in homogeneous as well as non homogeneous environment is done in this paper. Comparison and evaluation is done by real experimental data collected by sea field trials.