中文摘要：

中高轨道合成孔径雷达具备潜在的高分辨宽测绘带能力,在国防和经济建设中具有重要的应用前景。针对传统星载SAR信号模型在中高轨道SAR建模中的缺陷和不足,作者提出了改进斜视距离模型和多项式逼近距离模型两种中高轨道SAR信号建模方法。本文在阐述了距离模型参数估计方法和估计精度的基础上,建立了简洁精确的二维频谱解析表达式,并发展了中高轨道SAR距离多普勒算法。仿真实验表明,本文提出的两种信号模型能够满足中高轨道SAR精确建模和成像处理要求。

英文摘要：

Since medium-earth-orbit SAR is capable of obverving with high resolution and wide swath,it will be helpful for national defence and development.Two novel rang for medium-earth-orbit SAR are introduced to deal with the limitation and insufficiency of the conventional signal modeling approch：the advanced hyperbolic and the polynomial fitting range models.The estimation technique and the estimation accuracy of the range model parameters are discussed,and the analytical apectra are deduced out consiely and precisely,as well as the range doppler algorithm is develpoed.Simulation results verify that the approaches proposed in this paper can satsfy the requirements of signal modeling and imaging for medium-earth-orbit SAR.