Land subsidence in Cangzhou of the North China Plain, has been an ongoing problem for the past four decades (since the later 1970s). With the development of new synthetic aperture radar(SAR)sensors and interferometric synthetic aperture radar(InSAR) techniques, the application of satellite Radar data have enhanced capabilities to detect and monitor ground displacements with centimeter to millimeter precision at greater spatial detail and higher temporal resolution. We use Permanent Scatterers interferometric synthetic aperture radar（PS-InSAR）technology (Hooper, A.2004) to detect and measure ground movement in this area（from2004 to 2007）. Results of the cangzhou region study are reported and the utility of the InSAR methodology is discussed.
Detecting land subsidence near metro lines in the Baoshan district of Shanghai with multi-temporal interferometric synthetic aperture radar
