Urban damage detection using decorrelation of SAR interferometric data

We investigate decreasing interferometric correlation of SAR data caused by building damages in urban area. We analyze JERS-1 SAR data pairs straddling the occurrence of the 1995 Hyogoken-nanbu earthquake. The distribution patterns of the pixels which indicated interferometric decorrelation correspond well with the building damaged area reported by the ground survey. The degree of decorrelation shows obvious correlation with the damaged building ratio on the area in each block and measured seismic intensity from strong motion data. The result of this study indicates a fact that the building damage causes the interferometric decorrelation. We also try to extract the urban area damaged by the 2001 Gujrat (western India) earthquake using Radarsat data. For practical use of interferometric decorrelation to detect the urban damage, effect of building type and urban concentration should be examined. These results show the applicability for interferometric analysis of SAR data to urban disaster management.