Estimation of three-dimensional crustal movements from mutli-temporal TerraSAR-X intensity images

A method for capturing the two-dimensional (2D) surface movements from two temporal TerraSAR-X (TSX) intensity images has been proposed by the authors in previous research. However, it is impossible to detect the three-dimensional (3D) actual displacement from one pair of TSX images. Hence, three pairs of TSX images taken in ascending and descending paths were used to estimate 3D crustal movements in this study. First, the 2D crustal movements due to the 2011 Tohoku earthquake were detected from the three sets respectively. The relationship between the 3D actual displacement and 2D converted movement in SAR images was derived according to the observation model and shooting condition of the SAR sensor. Then the absolute 3D movements were estimated by the combination of the detected 2D movements that occurred within a short time interval. The results were verified by the GEONET observation records.