摘要
由于地球同步轨道SAR(Geo-SAR)较高的轨道高度和较长的合成孔径时间,"走-停"("Stop-Go")假设所带来的误差必须予以考虑。该文推导并模拟了正圆轨道下地球同步轨道SAR(Geo-SAR)的精确回波延时方程,分析并仿真了其与"走-停"模型误差。提出了一种"等效中点"模型,并通过仿真验证了该模型能很好地拟合精确距离历程。采用基于高阶多普勒参数的多项式拟合对"等效中点模型"和"走-停"模型的斜距历程进行展开,借助Legendre正交级数展开定量分析了"走-停"模型所带来的各个幂次的斜距误差,进而分析了各幂次斜距误差对于聚焦效果的影响。通过点目标仿真证明了"走-停"模型应用于Geo-SAR的局限性与"等效中点模型"的有效性。
Due to the high orbit and long synthetic aperture time of Geosynchronous SAR（Geo-SAR）, the error brought by the ＂Stop-Go＂ assumption has to be considered. In this paper, an accurate signal propagation delay time equation of Geo-SAR based on circle orbit is presented, and the error of ＂Stop-Go＂ assumption is shown by simulation. An ＂equivalent position＂ model is proposed, and is validated through simulation. Error of different powers of ＂Stop-Go＂ slant range is analyzed using Legendre orthogonal series expansion. The limitation of ＂Stop-Go＂ assumption and the availability of ＂Equivalent Position＂ mode are proved by point target simulation.
出处
《电子与信息学报》
EI
CSCD
北大核心
2014年第8期1960-1965,共6页
Journal of Electronics & Information Technology
