地基SAR作为一种新型地面遥感技术, 因其高精度、全天候、设站灵活、实时连续观测等特点, 在微形变监测领域具有广泛的应用前景。在深入研究了地基SAR微形变监测关键技术问题的基础上, 结合基坑监测特点, 采用加权圆周中值滤波去噪, 提高干涉图信噪比, 削弱噪声引起的相位差; 提出了基于PSC网的气象改正, 减小气象扰动影响, 削弱大气相位差。并将改进方法应用到基坑监测实验。实验结果表明, 通过加权圆周中值滤波和PSC网的气象改正有效地削弱地基SAR基坑监测中噪声和大气引起的相位变化, 实现了亚毫米级的监测精度。为验证地基SAR监测的准确性, 利用高精度全站仪进行了同步观测, 监测结果表明二者高度一致, 进一步说明了地基SAR技术用于基坑微形变监测的可靠性和可行性。

The ground-based SAR, as a new type of ground remote sensing technology, is widely used in the field of microdeformation monitoring because of its high precision, all-weather, flexible and real-time continuous observation. Based on the deep research on the key technical problems of micro-deformation monitoring of ground-based SAR, combined with the characteristics of foundation pit monitoring, the method of weighted median filter denoising was used to improve the signal-to-noise ratio of interferogram and weaken the noise phase difference. The method of atmospheric correction based on the PSC network was proposed to reduce the impact of meteorological disturbances and weaken the atmospheric phase difference. The improved methods were applied to the foundation pit monitoring experiment. The experimental results show that the weighted median filter and PSC network weather correction effectively weaken the phase change caused by noise and atmospheric, and achieve monitoring accruacy of submillimeter. In order to verify the accuracy of ground-based SAR monitoring, the synchronous observation is carried out using high-precision total station, the monitoring results are consistent with the results of ground-based SAR, which verifies the reliability and feasibility of ground-based SAR technique in monitoring the microdeformation of pits.