3D orbit selection for regional observation GEO SAR

Although Geosynchronous Synthetic Aperture Radar (GEO SAR) has the advantages of large footprint and short revisit time, the problem of pseudo coverage, which means “visible but not imageable,” should be investigated due to the side-looking imaging requirement of SAR. Therefore, how to learn an optimized 3D orbit is an important task. In this article, we propose the concept of “pseudo coverage” for the first time. Besides, we address the 3D orbit selection for regional observation GEO SAR and deliver the mathematic model of imageable area considering pseudo coverage. The GEO SAR coverage performance is analyzed using numerical simulation and 3D orbit traversal. Finally, considering the constraints of coverage performance, system design, and project reliability, the GEO SAR 3D orbit is selected and the coverage performance of four typical orbits is evaluated.