Baseline Accuracy Analysis for Sub-Geosynchronous Orbital Tomo-SAR System

摘要

This manuscript discusses some problems about Sub-Geosynchronous Orbital(SGO) Tomo-SAR system, including baseline linear array model, signal model and orbital determination accuracy influences on imaging results. The cell array interval and baseline length is calculated according to the demand of cross-range resolution and ambiguity. A sub-geosynchronous orbit is designed to form baseline meeting the requirements above through satellite's longitudinal drift. The orbital height controlling and determination accuracy both bring phase error. This paper firstly analyses and simulates the SGO-Tomo-SAR baseline linear array pattern properties, and advances four principles for baseline designing. Secondly, the characters of radar signal are illustrated. Furthermore, the effects from the system non-ideal factors are discussed, such as non-uniform distribution of tracks and the orbital determination error. Finally, an L-band mode SGO Tomo-SAR system with 3-D resolution around 50m is employed to process a simulation experiment to verify the theories above.