融合区域生长的DS-InSAR相位优化与应用

Research and Application of DS-InSAR Phase Optimization Based on Regional Growth

常规时序合成孔径雷达干涉测量(interferometric synthetic aperture radar,InSAR)技术应用于矿区地表形变监测时存在监测点少且分布不均等不足,难以全面反映采空区地表变形特征,而分布式目标受时空失相干等因素的影响相位稳定性较差,因此开展分布式目标相位优化是融合分布式目标时序InSAR形变监测的关键步骤。针对当前分布式目标相位优化中存在的空间连续性约束不足问题,提出了融合区域生长的分布式目标相位优化方法,开展时间和空间联合约束下的分布式目标相位优化,实现复杂地表环境下的精细化地表形变信息获取,并以潘安湖区域为例对分布式目标相位的优化效果进行了定性和定量分析。在此基础上,以该方法和Sentinel-1数据开展了徐州市废弃矿区2018-05—2020-05的地表形变监测,并利用连续运行参考站和裸露基岩验证了该方法的精度和可靠性。结果表明,分布式目标相位时空二维优化方法能够有效减小相位噪声影响,有助于城市废弃矿区地表形变监测。

Objectives:When the conventional time-series interferometric synthetic aperture radar(InSAR)technology is applied to the surface deformation monitoring of mining areas,it is difficult to fully reflect the surface deformation characteristics of the goaf due to the uneven distribution and small number of monitoring points.In addition,distributed scatterers are seriously affected by the temporal and spatial incoherence.Thus the corresponding phase optimizing operation is a key step in fusing distributed scatterers(DS)points into time-series InSAR analysis.The current constraints of phase space continuity in the phase optimization of distributed targets are insufficient.Methods:A phase optimization method based on the region growing algorithm is proposed.The detailed surface deformation information in complex environment could be obtained by optimizing phase in both time and spatial domain.The optimized phase of distributed scatter is evaluated qualitatively and quantitatively in Pan'an Lake area.Results:The proposed method and Sentinel-1 data are used to investigate the surface deformation of abandoned mining areas around Xuzhou from May 2018 to May 2020.Besides,the accuracy and reliability of this method are proved by continuously operating reference stations results and bedrock-exposed area.Conclusions:The result indicates that the method gives a good performance on reducing phase noise by two-dimensional phase optimization of distributed scatterers,which would be good for obtaining the surface deformation information in the abandoned mining areas.