星载InSAR空间基线指向优化与设计

分布式卫星SAR系统是近年来受到广泛重视的一种新的雷达成像手段,其中分布式InSAR充分利用编队星座卫星间构成的空间基线进行干涉测高,从而实现立体成像.在InSAR系统设计中,解决好编队星座的设计问题是实现高性能成像的前提和保证,合理的星座构形设计有助于提高测高精度,从而获得高品质的雷达成像效果.从InSAR测高精度分析结果入手,由飞行力学角度阐述星间相对运动对测高精度产生的影响,并基于分析结果给出了一种有别于现有星座的特色编队构形,并对其性能进行了初步分析. 

Optimization and Design of Baseline Direction of Satellite InSAR System

The satellites SAR system is an imaging technology that has been paid much attention recently, one of the examples is InSAR system, which provide 3D image by interferential height measurement based on the formation flying satellites' baselines. In formation flight InSAR system, the configuration of satellites' constellation should be carefully designed to achieve a high precision and good quality. In this paper, the influence of height measurement accuracy that caused by satellites relative motion is studied with analysis on measurement precision of the height and flight dynamics. Two types of baseline directions were discussed in particular. One type is "vertical baseline" and the other is "horizontal baseline". On the basis of analysis, the concept of "preponderant arc" is put forward. The analysis can be used to determine the satellites' formation. Utilizing Hill-equation, the expressions of how the length, azimuth angle and pitch angle transformed with time were given. Finally, a new constellation configuration different from current system based on the analysis results is proposed. This formation includes three satellites, two satellites run concomitantly in a vertical plane, and the other runs in a sidelong plane. Some basic analyses for the performance are also presented. The simulation shows that this formation is feasible.