DEM辅助的山区InSAR相位解缠

针对山区InSAR相位解缠困难的问题,在实现零中频矢量滤波的基础上,设计了DEM辅助的山区InSAR相位解缠方法。将原始干涉图与DEM模拟的干涉图做差分处理,获取条纹中心频率极低的零中频干涉图,再对零中频干涉图进行滤波和相位解缠处理;并将解缠结果和模拟干涉相位求和得到原始干涉图的解缠结果,从而减小相位欠采样和频谱混叠现象对干涉处理的影响,提高相位解缠性能。采用兰州地区和登封地区两套ENVISAT ASAR数据进行相位解缠实验,统计解缠百分比、解缠效率,以及零中频干涉图对应的相干图和常规干涉相干图构成的差分相干图的相干值均值,验证方法的可行性和有效性。

Phase Unwrapping Assisted by DEM of InSAR for Mountainous Terrain

For the difficult phase unwrapping problem in complex mountainous terrain,a phase unwrapping method assisted by DEM of InSAR for mountainous terrain was designed based on the idea of zero intermediate frequency vector filtering.The conventional interferogram and simulated interferogram were made difference processing,and zero intermediate frequency interferogram with very low stripe center frequency was obtained.After filtering and unwrapping,the unwrapped results of the conventional interferogram were obtained by adding back the simulated phase detracted before,which removed the effects of phase undersampling and aliasing,and improved the performance of phase unwrapping.Two sets of data in Lanzhou and Dengfeng regions were tested.The results proved the feasibility and effectiveness of this method by unwrapping percentage,unwrapping efficiency,and the mean of the differential coherent map composed of coherent maps respectively corresponding to the zero intermediate frequency interferogram and the conventional interferogram.