Techniques for seismic damages assessment by using remotely sensed images

This paper discusses the methods of seismic damages assessment by utilizing remotely sensed data. Classical Change Detection (CD) algorithms are effective when the author can acquire both pre and post-event images in a very short period of time. For images those have large temporal difference, edge detection and neighborhood operations and occurrence calculations are used to enhance the texture information and detect the displacement of outlines of ground objects. When there is only post-quake image, the Direct Recognition from Single Image (DRSI) method is used. But automated DRSI is difficult because the pattern of houses is very complex and varies greatly in different geographical areas. Experiments were carried out for 2003 Jiashi-Bachu Ms 6.8, 1999 Taiwan Jiji Ms 7.2 and 1998 Zhangbei Ms 6.2 quakes. SPOT, ERS-2 SAR and airborne images were obtained. The results were in agreement with field surveys.