Tianjin suburbs PS-QPS analysis and validation with leveling data

Permanent Scatterers (PS) based on Synthetic Aperture Radar (SAR) data has been approved to be a feasible way to detect and monitor wide area ground subsidence at a low cost. Classical PS algorithms are focused on exploring the point-like radar targets while Quasi-PS (QPS) technique was proposed to manage the detection of both distributed and decorrelating targets. In this work, we explore the potential ability of PS and QPS analysis for subsidence monitoring with L- and X-band. A case study was conducted in Tianjin suburbs and the exploited SAR datasets were composed of 23 ALOS images acquired from 2009/4/24 to 2010/10/28 and 37 TerraSAR-X images from 2009/4/29 to 2010/11/11. The average subsidence velocity map and displacement history have been retrieved by PS and QPS analysis and the validation indicates good agreement between INSAR time series results and leveling data.