Land Deformation Monitoring using Synthetic Aperture Radar Interferometry

Abstract

Most areas of Southeast Asia are located at the junction of four of the world's major plates, namely the Eurasian, Australian, Philippines and Pacific plates. The many interactions occurring at the edges of these plates result in a hazard-active environment with frequent ground deformation. Tsunamis, earthquakes, and volcanic eruptions kill a lot of people every year in Indonesia. Therefore, the study of ground deformation of Southeast Asia has attracted great attention in recent years.

Synthetic aperture radar interferometry (InSAR) and differential interferometry (DInSAR) techniques have been successfully employed to construct accurate elevation and monitor terrain deformation. This technique makes use of active radar transmitters and receivers to monitor ground deformation. The measurement of phase differences at the same ground surface pixel is the main signal processing method. Since the C and X bands have poor signals over vegetation areas, the utilization of L-band SAR data overcomes the challenge of the low coherence over the rainforest areas of Southeast Asia.

In this dissertation, the general SAR processing technique is first introduced. Secondly, ground deformations related to seismic and volcanic processes are discussed in several areas of Southeast Asia (the 2009 Papua and 2009 Haiti earthquakes, and the Merapi and Luci volcanos). Following a discussion of the difficulties of INSAR in Southeast Asia, a new method for baseline correction, is presented. This method introduces the new idea that relative satellite position can be estimated from the interferometry results. By applying this method, orbital inaccuracy is calibrated iteratively, and the standard deviation substantially decreases within a few iterations. The method has good potential in platform position correction and the accuracy improvement of deformation monitoring in Southeast Asia.