ALOS/PALSARデータを用いたPS干渉SAR解析の精度評価—千葉県九十九里地域の地表変動を例として

抄録

Persistent scatterer interferometry is a method for mapping surface displacements using satellite-based synthetic aperture radar data. Because of its strong advantage in mapping broad surface displacements accurately and with high spatial resolution, persistent scatterer interferometry has been successfully applied to a variety of displacement phenomena such as ground subsidence and landslides. Although previous studies have evaluated the accuracy of the method, to the best of our knowledge, no theoretical evaluation using simulation data for ALOS/PALSAR L-band data has yet been carried out. In this study, we evaluated the accuracy of persistent scatterer interferometry of ALOS/PALSAR data using simulated and real SAR data analyses, and investigated surface displacement in the Kujukuri Plain, Chiba Prefecture, Japan. Our simulation study showed that the RMSE of time-series displacements was 1.14cm and the mean absolute difference of annual displacement velocity was 0.20cm/year. In our real data analysis, the RMSE values of persistent scatterer interferometry results at two GPS stations were 0.50 and 0.65cm, and the absolute differences of annual displacement velocity were 0.07 and 0.08cm/year. This high accuracy and the detailed spatial distribution would be effective for surface displacement monitoring. Moreover, the present evaluation of theoretical accuracy with simulated data would be useful for analyses with a variety of satellite SAR data and areas of interest.