雷达影像地表形变干涉测量的机遇、挑战与展望

随着合成孔径雷达(SAR)卫星的不断发射,合成孔径雷达干涉测量技术(interferometric synthetic aperture radar,InSAR)得到前所未有的发展机遇,同时也面临诸多挑战。本文首先简要介绍了SAR卫星发展现状与InSAR技术的基本原理,并系统梳理了干涉图堆叠(InSAR stacking)、小基线集干涉测量(small baseline subset InSAR,SBAS-InSAR)、永久散射体干涉测量(persistent scatterer InSAR,PS-InSAR)、分布式散射体干涉测量(distributed scatterer InSAR,DS-InSAR)和分频干涉测量(split-bandwidth interferometry,SBI)等先进InSAR技术的优缺点。在此基础上,指出目前InSAR技术面临的主要挑战(相位失相干、大气延迟、相位解缠、几何畸变和多维变形测量)及相应的解决方案。进一步从地震、火山、滑坡、地面沉降、冰川运动、人工建构筑物位移变形及大气水汽含量估计等不同的应用场景分析了InSAR技术的应用现状和存在的缺陷。最后,展望目前InSAR的发展趋势,随着更高空间分辨率,更高时间分辨率,更轻小化SAR卫星的不断发展,InSAR技术将会被应用到越来越多的新场景,激励我国雷达影像干涉测量更快发展。

Interferometric synthetic aperture radar for deformation mapping: opportunities,challenges and the outlook

With frequent launches of synthetic aperture radar (SAR) satellites, interferometric SAR (InSAR) technology has been presented with unprecedented opportunities along with many new challenges for deformation mapping. In this paper, we concisely demonstrate the current development of SAR satellites and the principle of the InSAR technique, and then systematically review the advantages and disadvantages of a set of advanced InSAR techniques including InSAR stacking, small baseline subset InSAR (SBAS-InSAR), persistent scatterer InSAR (PS-InSAR),distributed scatterer InSAR (DS-InSAR) and split-bandwidth interferometry (SBI).On this basis, major challenges currently hampering InSAR applications (e.g., coherent loss, atmospheric distrubence, phase unwrapping errors, geometric distortions and multi-dimensional surface displacements) are investigated and their corresponding possible solutions are discussed. Then, we review the current status, particularly their limitations, of various typical InSAR applications under different scenarios such as earthquakes, volcanoes, landslides, ground subsidence, glaciers, infrastructure displacement monitoring, and atmospheric water vapour mapping. Finally, we present the outlook of InSAR, suggesting that with the continuous development of higher spatial resolution, higher temporal resolution and smaller SAR satellites, InSAR shall be applied to a number of new applications that cannot be achieved by traditional methods, bringing greater inspiration to the development of InSAR in China.