针对现有文献采用地球同步轨道合成孔径雷达(GEOSAR)测量地形高度和地貌形变时误差较大的问题,提出了一种新的GEOSAR干涉测量模型.在考虑地球曲面、斜距、基线、平台高度、干涉相位和数字高程模型(DEM)等因素的情况下,推导了干涉GEOSAR的绝对测高精度、相对测高精度与形变测量精度的数学模型,建立了一种既适用于高轨干涉SAR系统,也适用于低轨干涉SAR系统的干涉测量模型.根据该模型计算了GEOSAR测高误差和形变测量误差,并与实验仿真结果进行了比较,验证了该模型的有效性.研究结果表明,所提GEOSAR干涉测量模型与Bruno所提模型相比,适用范围更广,且误差精度提高至米量级.
For the low measuring accuracy of terrain height and deformation by geosynchronous synthetic aperture radar (GEOSAR) in available literatures, a new GEOSAR interferometry model is presented. This model is suitable for both high orbit SAR and low orbit SAR, and the mathematical expressions of the accuracy of absolute height, relative height and change detection are derived by considering the earth curve, slant range, baseline, platform height, interferometric phase and digital elevation model (DEM). The height and deformation errors in the new model are evaluated and compared with those from the simulated experiments to confirm the validity of this model. It indicates that the newly proposed model is suitable to a wider application range than Bruno's model with an accuracy of meter level.