Advanced SAR Processing Techniques

Ultra-wideband (UWB) synthetic aperture radar (SAR), in the UHF frequency range, provides an ability to perform all weather wide area surveillance, terrain mapping, target ID, and geolocation, by imaging the environment under tree canopies, with ground and foliage penetration. The objective of this Phase I effort is to demonstrate novel robust analysis approaches to SAR focusing, radio frequency interference (RFI) rejection, and image formation and registration. Radar provides all weather capability. Wide bandwidth provides fine range resolution. A long coherent synthetic aperture provides fine cross range resolution. Foliage and ground penetration requires a low operating frequency. Wide bandwidth at low frequencies entails interference from radio and TV stations and from cellular and mobile radio. The emphasis of the proposed work involves the attainment of wideband coherence over extremely long synthetic apertures while rejecting RFI. The result of such work will be techniques, algorithms, and software that produce high quality (resolution, accuracy, and dynamic range) SAR images suitable for high performance targeting or mapping under difficult imaging conditions. The robust autonomous motion compensation techniques (a) can operate with only the radar data, 9b) do not require targets in the scene, and (c) can compensate for large trajectory deviations.