Dual-Channel Joint SAR-Interferometry via Superresolution Spectral Estimation

Abstract

Interferometric synthetic aperture radar (SAR) utilizes the phase difference between two images formed from separate channels to extract information from the imaged scene. Dual-channel systems provide a compromise between multipass and multichannel setups in that greater coherence between the channels is achieved while still being physically realizable. However, dual-channel systems suffer from less stability in phase estimates due to the inability to undergo sufficient averaging to reduce thermal noise. Spectral estimation techniques have the ability to reduce these effects and provide stable, accurate intensity and phase estimates. This article presents a novel extension of a previously developed technique for height estimation to the Amplitude and Phase EStimation (APES) filter, and develops a novel technique using linear prediction filters. In addition, the three techniques are extended to along-track interferometric phase stabilization for moving target indication (MTI). Quantitative results show APES performs best with respect to bias and standard deviation. Along-track interferometry (ATI) and topographic interferograms are presented to visually demonstrate performance improvements.