地球同步轨道星载合成孔径雷达(Geosynchronous Synthetic Aperture Radar,GEOSAR)具有超高的卫星轨道和超长的合成孔径时间,相比于目前的低轨星载SAR,GEOSAR在信号特性与成像信号处理方面变化显著。GEOSAR体制和理论方法的研究都要以GEOSAR自身的特性分析为基础。文中根据GEOSAR的星地几何关系对星下点轨迹、卫星速度与波束扫描速度、合成孔径时间、多普勒特性等观测特性进行了深入分析,然后在此基础上与典型低轨SAR进行比较,得出了相应结论。

Compared with current low-earth orbit spaceborne SAR, GEOSAR is featured in its ultra-high orbit and ultra-long integration time which has great improvement in signal properties and imaging processing. Study of GEOSAR system and theory shall be based on the analysis of its characteristics. A deep analysis of observation properties such as the sub-satellite point under the earth, the satellite velocity and the ground velocity of beam, integration time and Doppler properties which are based on the geometrical relationship of the satellite and the ground is made in this paper, and the conclusion is given based on the comparison with the typical low-earth orbit SAR.