Land subsidence of the northern Kanto plains caused by ground water extraction detected by JERS-1 SAR interferometry

The authors detected the land subsidence caused by the groundwater extraction in the northern Kanto area, Japan by synthetic aperture radar interferometry (InSAR) using Japanese Earth Resources Satellite-1 (JERS-1) data. They process twenty interferometric pairs and obtain interferograms. The comparison of the vertical displacement at benchmarks from InSAR and leveling results show that the correlation between InSAR and leveling is quite good for each interferometric pair, but positive bias is found in the vertical displacement derived from InSAR for all the interferometric pairs. The bias probably comes from the inappropriate baseline estimation in InSAR process