Region-Based Co-Seismic Ground Displacement Dectection Using Optical Aerial Imagery

Ground analysis is important after an earthquake occurred in order to understand the surface variations. By optical imagery before and after a disaster, this paper tries to find the co-seismic ground displacement using region-based image patches. By comparing the similarity of pre- and post-event orthophotos, regions of ground changes can be detected. Conjugate objects were then recognized through feature extraction and image matching. An image with pose parameters can estimate the three-dimensional positions of those objects in the world space. Thus, three-dimensional geometric correlation between the pre- and post-event objects can measure the ground displacement. The results indicate that the proposed approach is able to estimate the co-seismic ground displacements based on the spatial information from optical imagery. In addition, surface shifts can be identified based on the spatial correlations.