中文摘要：

星载SAR无控制点定位可利用距离-多普勒（R-D）模型和有理多项式（RPC）模型两种方法实现。为考察二者在不同高程条件下的适用性,本文利用Radarsat-2数据,基于绝对定位误差小于1m的GPS控制点,对R-D模型和RPC模型定位精度进行了对比分析。结果表明：在无高程数据仅利用头文件元数据的情况下,R-D模型和RPC模型定位精度都较差;当代入高程数据后,R-D模型表现出因高程变化引起的更好定位精度一致性。

英文摘要：

The space-borne SAR location without reference points can be realized by two models,i.e.,the Range-Doppler（R-D） model and the rational polynomial coefficients（RPC） model.To evaluate the applicability of both models under different elevations,the R-D model and the RPC model are analyzed and compared based on the Radarsat-2 data in this paper,by utilizing the GPS controlling points with the accuracy of 1 meter.Experimental results indicate that both models can not work efficiently without any elevation information,provided that only the meta-data are used in the header file.However,if the elevation data are utilized,the R-D model presents better consistency of location precision when elevation varies.