P-Band UAV-SAR 4D Imaging: A Multi-Master Differential SAR Tomography Approach

Due to its rapid deployment, high-flexibility, and high-accuracy advantages, the unmanned-aerial-vehicle (UAV)-based differential synthetic aperture radar (SAR) tomography (D-TomoSAR) technique presents an attractive approach for urban risk monitoring. With sufficiently long spatial temporal baselines, it offers elevation velocity resolution beyond dimensions of range azimuth, enabling four-dimensional (4D) SAR imaging. In case P-band UAV-SAR, a spatial-temporal baseline is necessary achieve high enough elevation-velocity dimensional resolution. Although UAV-SAR maintains coherence, still faces two issues due extended baseline, i.e., low coherence sidelobes. To tackle these problems, we introduce multi-master (MM) D-TomoSAR approach, contributing three main points. Firstly, traditional signal model MM one, which improves average coefficient number baselines (NOB) as well suppresses Secondly, distribution optimization processing proposed equalize spatial–temporal distribution, more uniform spectrum samplings, reduce Thirdly, clustering-based outlier elimination method employed ensure 4D imaging quality. The effectively validated through computer simulation experiment.