ALOS PALSAR D-InSAR for land subsidence mapping in Jakarta, Indonesia

Differential synthetic aperture radar interferometry (D-InSAR) is a technique capable of detecting land surface deformation. In this research, we use Advanced Land Observing Satellite (ALOS) Phased Array L-band SAR (PALSAR) data to investigate land subsidence in Jakarta during 2007 and 2008. It is found that four northern areas in the city exhibit clear indications of land subsidence. The location of the centre of subsidence is estimated, and the subsidence volume is evaluated for each area using the unwrapping method as a further process of using D-InSAR results. The subsidence depth and volume around the centre are estimated to be 10-22 cm and 0.2 x 10(5) - 4.2 x 10(5) m(3), respectively, in the study time period. Comparison with ground survey data indicates that the D-InSAR analysis gives reliable estimates of the subsidence in an urban environment.