Ground Displacement Measurement by TerraSAR-X Image Correlation: The 2011 Tohoku-Oki Earthquake

Japan was struck by an M9.0 megathrust earthquake on March 11, 2011. Synthetic aperture radar (SAR) images from the TerraSAR-X satellite have been used to generate a ground motion map by means of correlation techniques. Geophysical corrections due to solid Earth tide and atmospheric path delay effects have been applied. These corrections can reach up to 20 cm in the radar line of sight. Using this approach, absolute displacements in the radar line of sight and in the satellite flight direction are determined. This letter shows the potential of correlation techniques for ground motion monitoring and a comparison with the interferometric technique. Using multiple scenes, a wide area displacement map is generated and quantitatively compared with GPS data, showing a divergence of about 15 cm.