基于地基和星载高分辨率SAR的矿山地表全尺度形变监测研究

Spaceborne InSAR techlonogy is an effective tool used for urban ground subsidence monitoring.However,but it proves to be problematic by monitoring mining subsidence and sliding. Dense vegetation coveragy and rapid large-scale ground moving,lead to a serious decorrelation scenario. In these cases,conventional D-InSAR(Differential Interferometry Synthetic Aperture Radar,D-InSAR) using low-resolution data suffers from difficult phase unwrapping,the measurable displacemant value is also limited in a small range. How to implement the full-scale ground surfase deformation monitoring in mining area becomes a considerable scientific issue. This proposal aims to make some progress in the following aspects: to realize the high-precise monitoring for slow and small ground deformation by use of integration of high-resolution Spaceborne SAR and GB-SAR interferometry; to approach a new method of ground deformation measurement for large-scale movements and gradient by means of offset-tracking based on local covariance function and an innovative InSAR method "CR Based subband-InSAR". The CR Based Subband-InSAR can extend the original small radar carrier wavelength to a large virtual wavelength, and increase the displacement ambiguity, so reduce or eliminate the phase unwrapping process; finally, to investigate the fusion of the results from spaceborne SAR and GB-SAR interferometry for estimating the three dimentional deformation vector in mining area. It is expected that the achievements of the project may provide a theoretical and practical suppot to construct a flexible full-scale three dimentional InSAR ground surfase deformation monitoring system.

InSAR技术用于矿山开采沉陷与滑动测量比城市地面沉降监测更复杂。植被覆盖或大尺度地表沉滑会导致严重的雷达失相干，使得中低分辨率SAR差分干涉相位解缠困难，矿区塌陷甚至超出其可测量程，无法得到从毫米级形变到数十米形变的全尺度矿山沉滑结果。实现地表大小尺度形变有效监测已成为InSAR研究者关注的重大科学难题。本课题拟利用高分SAR的宽带宽、高回波强度等特性，研究联合高分SAR和地基SAR等数据的差分干涉方法，实现开采地表微小形变量测；研究基于互协方差函数的Offset-Tracking方法和结合CR的高分SAR数据的子带差分干涉技术，后者利用扩大虚拟波长和形变模糊度，减轻或避免相位解缠，解决包括严重植被覆盖地表的大尺度沉滑监测问题；研究星载SAR与地基SAR监测结果的融合，优化空间三维形变矢量，形成一套数据和方法的融合理论，为构建一个能应对矿山全尺度三维InSAR沉滑监测系统奠定理论基础。

本课题利用高分SAR的宽带宽、高回波强度等特性，研究高分SAR和地基SAR等数据及融合其他测量数据的差分干涉方法（SBAS、PS、DS、CRINSAR等），实现了开采地表微小形变高精度量测；研究了基于互协方差函数的Offset-Tracking方法和结合CR的高分SAR数据的子带差分干涉技术，扩大虚拟波长和形变模糊度，减轻或避免相位解缠，解决了包括严重植被覆盖地表的大尺度沉滑监测问题；研究星载SAR、地基SAR监测结果与其他测量数据的融合方法，优化了空间三维形变矢量，形成一套数据和方法的融合理论，构建一个能应对矿山隧道、滑坡及深基坑等全尺度三维InSAR沉滑监测系统，研制了矿区沉陷监测预警系统和地表形变安全预警监测系统。对植被覆盖或大尺度地表沉滑会导致严重的雷达失相干地区，及中低分辨率SAR差分干涉相位解缠困难地区，基本可以得到从毫米级形变到数十米形变的全尺度沉滑结果。实现了地表大小尺度形变的有效INSAR监测：进行了基于平滑样条PSInSAR大气效应分离，RS分析法对矿区地表沉陷预测，基于DORIS软件实现哨兵卫星TOPS模式影像的几何配准和增强谱分集优化配准处理；在地基SAR方面，针对其PS点选取局限性，提出了一种基于平均相干系数、振幅离差指数、估计信噪比、位移标准差的多重阈值优化的PS点选取方法，其选取结果的稳定性和质量都优于单一模型，提出了PS大气矫正法，采用大气矫正模型解算各PS点大气相位影响量，提高了形变监测结果。应用子带干涉技术获得了唐洞煤矿地表方位向位移，与同期GPS监测数据进行对比，进一步验证了子带干涉技术的形变监测能力，并用子带干涉技术将距离向宽带频谱分解成多个频带，然后进行干涉处理，实现了子带干涉高精度形变监测。