PSInSAR技术在换流站沉降监测中的应用

Application of PSInSAR for Subsidence Monitoring of Converter Station

沉降监测是换流站工程建设阶段及运维阶段中不可缺的工作。近年来,星载干涉合成孔径雷达(InSAR)技术凭借全天时、全天候、高采样密度以及无需测量人员进入实地等特点广泛应用于地表沉降监测中,InSAR技术为解决换流站及其周边环境的稳定性监测提供了新的途径。PSInSAR技术是一种时序InSAR技术,通过一系列SAR干涉图像中的永久散射体(PS)进行相位时空分析,获取毫米级精度的地表形变信息。采用28景Sentinel-1数据进行PSInSAR数据处理,提取了云南某±800 kV特高压换流站的时间序列沉降结果。结果发现,换流站多处位置出现沉降现象,最大沉降速率超过-12 mm/year。该结果表明了Sentinel-1数据与PSInSAR可以应用于换流站沉降监测中。

Subsidence monitoring is an indispensable task in the construction as well as operation and maintenance stages of converter stations.In recent years,spaceborne interferometric synthetic aperture radar(InSAR)technology,relying on its characteristics of all-time,all-weather,high sampling density and no need for surveyors to enter the field,has been widely used in surface subsidence monitoring.A new way is provided to monitor the stability of converter station and nearby environment with the InSAR technology.PSInSAR technology is a time-sequential InSAR that uses phase-space-time analysis of permanent scatterers(PS)in a series of SAR interference images to obtain ground deformation information of millimeter-level accuracy.The 28-scene Sentinel-1 data is used for PSInSAR data processing,and the time-sequential subsidence results of a±800 kV ultra-high-voltage converter station in Yunnan are extracted.It is found that subsidence occurs at multiple locations of the converter station,with the maximum subsidence rate exceeding-12 mm/year.The results show that Sentinel-1 data and PSInSAR can be used in the subsidence monitoring of converter stations.