부산대학교 도서관

Unmanned Aerial Vehicle (UAV)-based synthetic aperture radar (SAR) systems enable very accurate and cost-effective monitoring of local areas with unprecedentedly short revisit intervals. Unlike current spaceborne systems, UAV-based SAR systems are often characterized by a large fractional bandwidth, a short-range geometry and a broad range of incidence angles, due to the wide antenna beamwidth. This paper discusses how to exploit these characteristics to generate very accurate digital elevation models (DEMs) by combining multi-baseline SAR interferometry (InSAR) and stereo radargrammetry to achieve a more robust unwrapping of the interferometric phase. Based on the theoretical analyses and the specific characteristics of the UAV scenario, a multi-baseline InSAR experiment was planned and conducted. The DEM performance analysis and the simulations show that large baselines result in height accuracies in the sub-decimeter range, where geometric and volume decorrelation become the limiting factors. The demonstration of these concepts paves the way to height measurements with unprecedented accuracy and will also be of paramount importance for the design of future wideband, multi-baseline, or multifrequency spaceborne SAR missions.