Unbiased coherence estimator for SAR interferometry with application to moving target detection

A new maximum-likelihood estimator (MLE) for estimating the coherence between two synthetic aperture radar (SAR) channels is proposed. In contrast to conventional techniques, this estimator is unbiased for any number of samples and degrees of coherence. The performance of the new MLE is validated with results based on measured along-track interferometric data. It is demonstrated how such accurate coherence estimates can be used to define CFAR-detection thresholds for moving targets