Abstract: At present, the geological disasters of ground subsidence occur in many cities of China, which are particularly severe in the Yangtze River Delta region where subsidence has long duration, large-scale causing huge economic losses. Wuxi is one of the typical cities of the large-scale land subsidence in Yangtze River Delta. In this article, we use ten ALOS PALSAR images, the time series of land subsidence of Wuxi city from January 12, 2007 to March 10, 2011 is estimated using the small baseline subsets D-InSAR technology. The results show that obvious subsidence occurred in the Hui Shan area, and the settlement in other areas is relatively stable with the average settlement about 15 mm; The settlement spatial pattern changed during 2007-2009, but the settlement rate increased from 2009 to 2010. Experiments prove that the short baseline subset (SBAS) interference in long time series of large-scale subsidence monitoring is feasible and effective. The results of monitoring ground subsidence provide an important scientific basis for disaster prevention and mitigation, and enable policy makers to make the right decisions. In the meantime, we can also trace the history of engineering activities according to the subsidence.

Key words: InSAR, Small Baseline Subsets, land deformation, interference, atmospheric phase