Integrating Corner Reflectors and PSInSAR technique to monitor regional land subsidence

PSInSAR has been proved an operational tool for surfaces deformation monitoring due to its millimeters precision and dense spatial samplings. However, PSInAR derived deformation parameters including the average displacement velocity and displacement history can´t be compared directly with these measured by the conventional technique such as leveling and GPS since the different reference datum between these measurement system. In this work we present the method to integrate Corner Reflectors(CRs) and PSInSAR technique for regional subsidence monitoring. For reference offset compensation between PSInSAR and leveling, the method using homogenous leveling survey of dedicated CRs was established. Meanwhile, an improved PSInSAR technique based on time series analysis of coherent target within small baseline interferograms was proposed. The proposed method was applied for regional subsidence monitoring in Beijing area with an extent of 100 × 100km² by using the ESA ENVISAT ASAR data collected during the time of 2008 to 2009 year. Seven CRs were installed in test sites for reference compensation and PSInSAR measurement validation. The results demonstrated the accuracy and reliability of PSInSAR for regional subsidence mapping.