Use of Interferometric Satellite Sar for Earthquake Damage Detection

Synthetic Aperture Radar (SAR) is one of the most promising remote sensing technologies since it is not affected by clouds and lights. The SAR interferometric analysis, using phase information of backscattering echoes from objects on the earth’s surface, is successfully employed to quantify relative ground displacements due to natural disasters. In addition, the complex coherence derived from the interferometric analysis is a suitable and sensitive parameter for the detection of superficial change and the classification of land use. In this paper, we investigated the microwave scattering characteristics of the areas damaged by the 1999 Kocaeli, Turkey earthquake using satellite SAR. From the difference in backscattered intensity and coherence from an interferometric analysis of SAR images taken at different acquisitions, we found that the backscattering property in heavily damaged areas showed significant change, compared with that in minor damage areas. The relationship between building damage and difference of preand post-event SAR images was found to relate to the damage level. This trend in the hard-hit areas was due to the fact that the backscattered intensity and the intensity correlation of two images became low. The degree of coherence was found to be a good index to distinguish slight to moderate damage levels.