基于虚拟特显点的高精度InSAR性能评估方法

由于特显点的高相干性,基于图像特显点的InSAR性能评估方法存在指标计算偏高的技术缺陷.为了客观评价InSAR性能,通过在实际特显点邻域引入虚拟特显点作为评估样本点,提出一种改进的InSAR性能评估方法.该方法利用特显点的高信杂比特性,并通过实际特显点和虚拟特显点的精确相对定位,可准确估计虚拟特显点在SAR图像中位置坐标,同时避免了特显点高相干性的不利影响.全流程的分布式卫星InSAR信号仿真实验验证了虚拟特显点InSAR性能评估方法的有效性,绝对、相对干涉相位估计精度及绝对、相对测高精度等主要InSAR性能指标的计算精度更高.

An InSAR performance evaluation method based on virtual prominent scatterers

For the conventional prominent scatterers method, InSAR performance is over evaluated because of the higher coherence of the scatterers. An improved InSAR performance evaluation method is proposed based on virtual prominent scatterers(VPS). The VPS are some ordinary scatterers distributed around the prominent scatterers and treated as statistical samples. The pixel position of the VPS can be precisely estimated with the accurate relative geolocation because of the high signal to clutter ratio of the prominent scatterers. And the absolute/relative interferometric phase and height precisions can be more accurately calculated. Experiment results based on spaceborne InSAR signal simulation show the validation of the VPS-based method.