雷达差分干涉测量及其在地表沉降中的应用与展望

阐述了雷达差分干涉测量(D-InSAR)的基本原理,概括了国内外目前应用比较广泛的D-InSAR模型,针对长时间序列的城市地表沉降监测,应用较多的是基于相干点目标选择,相关的技术包括PSI、SBAS、CRT、CTA。通过多景数据的套合达到消除大气误差相位的目的。进一步总结了相关D-InSAR技术在地表沉降方面的应用进展。相关研究表明,D-InSAR技术能够应用于城市地表沉降监测,并且能够达到较高精度,逐步形成了完善的理论体系和技术处理流程。而且随着技术的发展,监测的时间尺度也在不断扩大、进一步拓展D-InSAR的试验区域。多种数据的结合和补充、方法的有效结合以及与传统的GPS、水准仪测量方法的结合是今后进一步关注的焦点和研究重点。

Monitoring Urban Ground Subsidence by Using Differential Interferometry Space-born Synthetic Aperture Radar

Differential Interferometry Synthetic Aperture Radar (D-InSAR),as a new technique to observe the ground,has been widely used to monitor urban ground subsidence,which attracts many researchers' attention in the world.By applying the principle of phase difference of the images at different time,micro-deformation within large area can be retrieved by D-InSAR.Typical D-InSAR includes two-pass,three-pass and four-pass models;as for monitoring ground subsidence at long time scale,some methodologies of dissimilar process,such as PSI,SBAS,CRT and CAT,were gradually promoted and tested by researchers,and their core is to retrieve coherent point targets exposing on interferograms.Related applications of D-InSAR on monitoring ground subsidence at home or abroad are further summarized,it proves D-InSAR effective for subsidence detection,and theoretic precision can be up to millimeter level.Primary theory and framework of data processing also have been formed.However,D-InSAR still has some errors in subsidence detection mainly due to the effect of the vegetation cover and weather variation.Up to now,detection of subsidence appearing in some regions is still under restriction.How to reduce the errors and what model would be used for measuring subsidence with optimization are still to be studied.In the future,D-InSAR will be more widely applied with more data resources. More attention will be paid to combination of datasets from multi-sensors to monitor subsidence with long time span.Monitoring urban ground subsidence in the future will be focused on integrating GPS and Leveling with D-InSAR.