基于PS-InSAR的1995—2000年苏州地面沉降监测

Subsidence of Suzhou Area from 1995 to 2000 Detected by Persistent Scatterers for SAR Interferometry Technique

永久散射体(PS)技术在传统差分干涉测量(D-InSAR)中引入时间维,分析长时间内保持稳定的像元集相位变化,获得毫米级的地面测量精度,但是该技术要求处理的范围较小。采用分块处理的方法,通过PS差分干涉测量处理,得到1995—2000年苏州地区地面沉降场的测量值。地面水准测量数据的验证分析表明,雷达差分干涉测量精度可达5mm(以水准测量代表地面形变的真实情况),基于分块处理的PS-InSAR技术在进行城市地面沉降监测和时空演化特征研究中具有很大的优势。

The Permanent Scatterers technique can reduce the spatial and temporal decorrelation by using a time series of SAR images and it has more accuracy,higher temporal resolution and utilization efficiency compared with traditional D-InSAR.However,with this technique some limitation should be noticed.For example,only small areas could be processed.Based on the fragmenting method,PS-InSAR map from 1995 to 2000 with high spatial detail and resolution of range displacement was developed in Suzhou area using radar data collected from ERS-2 satellite.The results validated by leveling surveys indicated that the accuracy of PS-InSAR observations reached 5 mm.We conclude that for the mapping of land subsidence in urban environments PS-InSAR has a strong potential with regard to cost effectiveness,resolution and accuracy.