A new PS selecting algorithm for monitoring Land subsidence with Persistent Scatterer Interferometry (PSI) and Polarimetry

Principal Investigator: Prof. Lin Hui

Start Date:	2007/12/26
End Date:	2009/12/25
Type of Grant:	Direct Grant for Research (2007-2008) ¡V 1st Round

In last thirty years, land subsidence has become one of the major geological disasters in urban areas in China. It is said land subsidence occurs in more than 90 cities in China. In Hong Kong, land subsidence has also been a problem mostly concerned in the reclaimed land from sea. Monitoring the land subsidence efficiently will not only help people identify the spatial and temporal pattern of this kind of disaster, but also guide people minimize the hazard ahead. Persistent Scatterer Interferometry (PSI) has been recognized as the most powerful tool to monitor the land subsidence in long time series and in large scale. However, it also has shortcomings. The PS is very hard to be detected in vegetable area. In PSI approaches, PS selection is the most difficult but important stage, the number and quality of PS directly affect the computed deformation result. All of the PSI approaches do not use the polarimetric information to select PS. In this project, a new PS selecting algorithm for monitoring the land subsidence by means of PSI associating with Polarimetry. The new algorithm is developed using not only the amplitude dispersion, spectral phase diversity, temporal and spatial coherent value but also polarimetric information. The physical characteristic of selected PS in urban area will be studied at the same time. And we will use the PS to be selected by the developed algorithm to estimate the deformation in urban area. Finally the field research will be executed to validate the results.