Constant false alarm rate detection of slow targets in polarimetric along‐track interferometric synthetic aperture radar imagery

Abstract

To improve the detection performance for ground moving targets with small radar-cross-section and low velocity in Along-Track Interferometric Synthetic Aperture Radar (AT-INSAR) system, this study explores new methods to elevate the target-to-clutter ratio by using full Polarimetric AT-INSAR (AT-POLINSAR). Three novel detectors that can achieve Constant False Alarm Rate (CFAR) detection are put forward for AT-POLINSAR at first, namely, the Suboptimal Interferometric Coherence Detector, the Generalized Polarimetric Whitening Filter and the Dual Detector. Secondly, the analytical expressions of their false-alarm rates are derived under the Gaussian distribution assumption of the six-dimensional polarimetric interferometric vector, then the estimation methods of distribution parameters and the calculating methods of detection thresholds as well as the specific implementation schemes of CFAR detection are given. Finally, the proposed detectors are compared with single-polarimetric AT-INSAR detectors and full polarimetric log-likelihood-ratio test through both the Monte Carlo detection experiments and the scene detection experiments of simulated AT-POLINSAR imagery, where the results indicate that new methods have rather higher CFAR detection performance and velocity estimation accuracy than current single-polarimetric detectors.