Bistatic and multistatic Synthetic Aperture Radar interferometric phenomenology and change detection

Abstract

Synthetic Aperture Radar (SAR) is an active remote sensing technique which allows for the collection of high-resolution imagery in any weather and in the day or night. SAR Coherent Change Detection (CCD) allows for the detection of very small scene changes. This is particularly useful for Intelligence, Surveillance and Reconnaissance (ISR) as small changes such as vehicle tracks can be identified. Rapidly collecting repeat pass SAR imagery is important in these applications. For space borne platforms, such repeat passes may however have significant baselines. CCD products are reliant on high coherence for good interpretability. This thesis investigates two main areas: The first is the sources and levels of incoherence associated with bistatic SAR imagery for a variety of baselines which maintained a high spatial frequency domain overlap. This investigation using simulations and measured laboratory data. This investigation showed the significant impact of the scattering parameter (added to the equations of coherence in this thesis) on the coherence of Rayleigh rough ground exhibiting speckle. Secondly the impact of different combinations of change detection images for multistatic and multi-polarimetric change detection is investigated. It is shown that combining multiple images can reduce the number of false detections and give improved performance (shown with performance metrics). This performance improvement is dependent on the processing which is chosen.