Abstract：Due to potential hazards, effective monitoring of land subsidence for urban areas has for a long time been very important. In this study, based on 23 images acquired from Sentinel-1A satellite, the PS-InSAR and SBAS technology as cross validation are used to examine land subsidence of the Nanjing area. The monitoring results indicate that both the range and magnitude of the land subsidence area from PS-InSAR technology agree well with SBAS technology. Moreover, significant land subsidence of the Nanjing area has been detected between April 2015 and January 2017, with the maximum subsidence rate exceeding -30mm/a.
