升降轨PSInSAR地面沉降监测结果的互检验与时序融合

Inter-comparison and time series fusion of ascending and descending PSInSAR data for land subsidence monitoring

升降轨PSInSAR时序分析获得的同一地区2组监测结果分别为升轨和降轨下的地表形变速率与累积变形量。针对研究区地面以下沉为主,水平方向变形极为微小的特点,将视线向(line of sight,LOS)变形转换为垂向的下沉值,以此进行升降轨模式下2组观测值的比较与精度检验。在此基础上,将相干目标的2组观测序列数据融合以实现加密观测。研究结果表明:升降轨模式下沉降速率观测值的互检验精度优于2 mm;2组观测序列数据的融合结果进一步揭示了相干目标在时域上的非线性沉降特征。

A joint analysis of ascending and descending tracks of PSInSAR provides deformation measurements with average velocity and time series of each coherent target for the same deformation zone, which allows the inter -comparison of the velocity map and the fusion of deformation time series. In this paper, the authors present the method of PSInSAR measurement inter -comparison and time series fusion by using ascending and descending ENVISAT data acquired from 2006 to 2010 for the purpose of subsidence monitoring. The inter -comparison of subsidence velocity in ascending and descending tracks demonstrates that the precision is higher than 2 mm, indicating the accuracy of single track PSInSAR measurement for land subsidence monitoring. The fusion of ascending and descending deformation series of each coherent target enables a detailed analysis of temporal behaviors because it provides dense observations in time.