ALOS/PALSAR and TerraSAR-X persistent scatterer interferometry around Tokyo: Interferometric phase evaluation and validation

In this paper we investigate the surface displacement pattern before and after the 2011 Tohoku earthquake using persistent scatterer interferometry of ALOS/PALSAR and TerraSAR-X images. For confirming the accuracy of the estimated displacement, interferometric phase components were evaluated and simulated data were created. Using the simulated data, the accuracy of filtering methods to mitigate tropospheric methods was evaluated. Real data processing clarified detailed spatial patterns of previously unrecognized displacement. Comparison with GPS data showed that the estimated displacement was within the expected accuracy of the simulated data. Our results demonstrate the effectiveness of the combination of ALOS/PALSAR and TerraSAR-X data analysis, and the accuracy evaluation by quantifying interferometric phase components.