Exploitation of Geometric Diversity for High Resolution Ultrahigh Frequency (UHF) Synthetic Aperture Radar (SAR) Imaging

Sky Research, Inc. proposes to investigate the application of geometric diversity to Ultra-High Frequency Synthetic Aperture Radar (UHF SAR) and to analyze the effects on coverage, resolution, and detection performance. Geometric diversity can be realized with curved, circular, or spiral flight paths, or by combining multiple straight or curved flight paths into a single coherent data set. The project will include an in-depth analysis of the image characteristics associated with geometric diversity, as well as evaluation of the idea of trading geometric diversity for bandwidth. The costs and benefits of these various flight path geometries will be evaluated and will include all of the aspects that are related to SAR image quality, such as resolution, sidelobe levels, and artifacts, and operational aspects such as coverage rate. Because the primary objective of many SAR systems is to detect targets, the evaluation of the effects of geometric diversity on target detection performance will be emphasized. The analysis will be verified by applying the techniques to actual UHF SAR data and then evaluating the effect on target detection performance in those data. BENEFIT: The application of geometric diversity to Ultra-High Frequency Synthetic Aperture Radar (UHF SAR) has several potential benefits over using non-straight flight paths. Some of the benefits of using non-straight flight paths, such as curved, circular, and multiple flight paths may lead to new application areas. These benefits include: following curved roads with curved flight paths; finding highly directive targets, such as wires, with circular flight paths; forming three dimensional images with multiple parallel flight paths; and improving image resolution and target detection performance with the geometric diversity provided by non-straight flight paths. The project will include an in-depth analysis of the image characteristics associated with geometric diversity, as well as evaluation of the idea of trading geometric diversity for bandwidth. The analysis will be verified by applying the techniques to actual UHF SAR data and then evaluating the effect on target detection performance in those data.