摘要
地球同步轨道发射、低地球轨道接收体制的天基雷达系统具有观测范围广、抗摧毁和抗干扰能力强、组网灵活等优点。分析发现,该系统中回波的包络不仅与地表场景的斜距有关,还与其方位位置有关,传统的单基SAR成像方法不再适用。本文分析了回波包络的历程,给出了适用于该系统的SAR成像方法。该方法根据多普勒参数以及目标像的几何形变量随接收卫星与发射卫星几何位置关系的变化特征对数据沿方位以及距离向进行分块,并重新构造距离徙动校正和方位匹配函数对回波信号聚焦,最后进行几何形变校正。仿真数据的成像结果证明了方法的可行性。
GEO-LEO distributed spaceborne SAR systems, in which GEO satellite is used as il- luminator and LEO satellite only used as signal receiver, have many advantages over conven- tional spaceborne SAR systems, such as wide observation range, strong anti-jamming and anti- destruction ability and flexible networking. However, traditional monostatic SAR imaging al- gorithms are not applicable to such systems since the echo time delay is coupled with the azi- muth position of the target. By analyzing the Doppler history of echo in detail, a novel SAR imaging algorithm for GEO-LEO bistatic spaceborne SAR systems is presented. According to the relationship between geometric distortion of target image and relative position of LEO sat- ellite, the method divides the SAR echo into many patches along the range and the azimuth di- rection, respectively. For each patch, new range migration correction and matching functions are constructed to focus on the echo. Finally, geometric distortions of target images in each patch are corrected uniformly. The feasibility of the proposed method is verified by experimen- tal results of simulation data.
出处
《数据采集与处理》
CSCD
北大核心
2013年第4期410-415,共6页
Journal of Data Acquisition and Processing
基金
陕西省自然科学基金(2011JQ8041)资助项目
中央高校基本科研业务费(CHD2012JC051)资助项目
关键词
合成孔径雷达
地球同步轨道
低地球轨道
几何形变
多普勒参数
synthetic aperture radar （SAR）
geosynchronous earth orbit （GEO）
low earth or-bit （LE（））
geometric distortion
Doppler parameters
