矿区地表大量级沉陷形变短基线集InSAR监测分析

Monitoring and analyzing large scale land subsidence over the mining area using small baseline subset InSAR

针对矿区地表大量级形变导致的InSAR影像配准精度低、可监测性差、探测量级小、地表沉陷前后完整形变信息难以获取等问题,研究了相应的偏移量追踪法、FFT过采样法、滤波技术与基线精化等数据处理方法,并利用短基线集(small baseline subset,SBAS)技术,使距离向配准精度、最大累积探测量级得到明显提高,矿区地表形变可监测性有了很大改善。研究结果表明,该方法不仅获得了2008—2011年间研究区开采进程中地表大量级沉陷的完整形变时间序列,而且其监测结果与外业实测数据以及采矿进程资料具有良好的一致性;通过对矿区地表形变剖线的统计分析,得到了开采工作面地表形变的时空演变规律。

Due to large scale earth surface deformation, the application of conventional InSAR technique to monitor land subsidence over the mining area has many limitations, such as low image co-registration accuracy and monitoring capability, small detection scale and unavailable complete mining subsidence information. In view of such a situation, the small baseline subset （SBAS） InSAR technique combined with offset tracking method, fast fourier transformation oversampling technique, filter technique and baseline refine method was studied in this paper to overcome the limitations. On such a basis, the co-registration accuracy, monitoring capability and the accumulative detection scale could be improved considerably. Meanwhile, the complete large scale time series deformation over the mining area from 2008 to 2011 was generated, which is well consistent with field and mining processing data. Furthermore, spatial and temporal evolution law of earth surface over the mining area was obtained by analyzing the cross-section time series deformation.