Abstract
Interferometric SAR (InSAR), which is an application technique of synthetic aperture radar, is becoming established as the method for monitoring of ground displacement that can observe subtle surface movement over a wide area at high resolution. In this study, the authors developed the method to measure a long-term deformation by combining InSAR and time series analysis, aiming at establishment of practical and flexible measurement technique. It utilizes smoothness constrained inversion which assumes the amount of deformation as unknown parameter for time series analysis. The proposed method separates with ground change and noise components from each combinations of InSAR, and composes long-term deformation.
We applied it to the measurement of ground subsidence around Kanto Plain with ENVISAT/ASAR data, and verified its accuracy by comparing with leveling data obtained around Kujukuri area. As a result, it was shown that the spatial shape of local uplift and subsidence areas detected by the proposed method were analogous with the deformation map generated from leveling data. In addition, it was also shown that the correlation coefficient between the result of proposed method and leveling data were high, although bias of about 10mm was included.
