极具应用潜力的PS技术

虽然在一些条件良好的地区,合成孔径雷达差分干涉测量(D-InSAR)技术已经取得了不少令人瞩目的应用成果,但时间失相干因素很大地限制了D-InSAR的广泛应用,而大气效应也会影响D-InSAR的测量精度。近年来提出的永久散射(Permanent Scatterers, PS)技术则在很大程度上解决了这两个难题,即使在无法获得干涉条纹的情况下,利用基于多时相SAR图像和相位稳定像元点集的PS技术也能取得毫米级的地表形变运动测量精度,因而PS技术大大增强了干涉测量的环境适应能力及其精度,是干涉研究领域的一项重大技术突破,具有巨大的实际应用潜力。首先着重介绍PS技术的原理及其处理过程,然后对PS技术的应用,以及PS技术与传统D-InSAR技术之间的关系进行扼要的讨论,期望有助于推动这项高新技术手段在国内的研究和应用。

The Permanent Scatterers Technique with Large Application Potential

Though in some areas of good condition remarkable application results have been achieved by using differential synthetic aperture radar interferometry (D-InSAR), to be regrettable, temporal decorrelation strongly confines the wide application of D-InSAR, and atmospheric phase screen also affects the accuracy of D-InSAR measurements. This two problems can be overcome in large extent by using Permanent Scatterers Technique (PST) developed in late years. Even if no fringes can be seen generating single interferogram, surface deformation measurements with millimetric accuracy can be obtained by using PST which based on series of temporal SAR images and on a subset of image pixels corresponding to phase stable areas. So PST greatly enhances the circumstances applicability of interferometry measurement and its accuracy, having been considered as an important breakthrough in interferometry research fields, which can produce large actual application potential. This paper introduces with emphasis on the principle of PST and its procedures, then discusses the application examples of PST and the contrast relation between PST and conventional D-InSAR. We expect the paper will be helpful for civil research work and applications of this advanced interferometry processing method.