Monitoring landslides and tectonic motions with the permanent scatterer technique
Wei-Heng , Liu
Abstract
? Discrete and temporarily stable natural reflectors or permanent scatterers (PS) can be identified from long temporal series of interferometric SAR images even with baselines larger than the so-called critical baseline. This subset of image pixels can be exploited
successfully for high accuracy differential measurements. We discuss the use of PS in urban areas, like Pomona, CA, showing subsidence and absidence effects.Anew approach to the estimation of the atmospheric phase contributions, and the local displacement field is proposed based on simple statistical assumptions. New solutions are presented in order to cope with nonlinear motion of the targets.
Spaceborne differential synthetic aperture radar interferometry (DInSAR) has already proven its potential for mapping ground deformation phenomena, e.g. volcano dynamics. However, atmospheric disturbances as well as phase decorrelation have prevented hitherto this technique from achieving full operational capability. These drawbacks are overcome by carrying out measurements on a subset of image pixels corresponding to pointwise stable reflectors (Permanent Scatterers, PS) and exploiting long temporal series of interferometric data.
The characteristics of PS, optical levelling surveying are to some extent complementary: a synergistic use of the three techniques could strongly enhance quality and reliability of ground deformation monitoring.
References
A. Ferretti , C. Prati ,F. Rocca , Nonlinear subsidence rate estimation using Permanent Scatterers in differential SAR interferometry.IEEE Trans. Geosci. Remote Sens. 38 (5), 2202– 2212, (2000)
A. Ferretti , C. Colesanti , C. Prati , and F. Rocca , Monitoring landslides and tectonic motions with the permanent scatterer technique, Engineering Geol., Spec. Issue Remote Sensing and Monitoring of Landslides, 68(1), 3-14 (2003).