Earthquake Damage Detection Using Synthetic Aperture Radar Imagery

卫星和航空遥感可以方便地以高分辨率监测大面积区域，可以提供有效的空间信息来探测地震造成的损害。作为安装在JERS和ERS卫星上的传感器，合成孔径雷达（SAR）是最有前途的技术之一，因为它不受云层的影响。SAR系统的一个显著特点是能够记录地面目标后向散射回波的幅度和相位。研究了1993年11月10日日本大地震和1993年北海道西南近海地震的ERS/SAR图像，探讨了利用卫星SAR提取地震灾害分布的可能性。根据地震前后SAR图像的后向散射强度和空间相关性的差异，发现受损区域的后向散射特性特征表现出明显的变化。建筑物受损与SAR图像之间的关系被发现与受损程度有关。当后向散射强度和事件前和事件后图像的相关性变低时，在建筑物严重损坏的地区显示出这种趋势。基于后向散射特性的判别分析提取的损伤分布与实际损伤调查结果一致。因此，遥感SAR图像可以成为灾后管理的有力工具。

Satellite and airborne remote sensing, which can easily monitor a large area with high resolution, can provide effective spatial information to detect earthquake-induced damage. As a sensor installed on satellites JERS and ERS, synthetic aperture radar (SAR) is one of the most promising technologies since clouds do not affect it One of distinctive characteristics of SAR systems is their capability of recording both amplitude and phase of the backscattering echoes from objects on the ground surface.The microwave scattering characteristics of areas damaged by the 1995 Hyogo-ken Nanbu (Kobe) earthquake and 1993 South-West off Hokkaido earthquake using ERS/SAR images was investigated for the purpose of possibility of extracting earthquake damage distribution by satellite SAR. According to the difference in backscattered intensity and spatial correlation of SAR images taken before and after the earthquake, it was found that the characteristics of the backscattering properties of damaged areas showed significant variations. The relationship between building damage and the SAR images was found to be related to the damage level. This trend in areas of heavy building damage was revealed when the backscattered intensity and the correlation of pre- and post-event images became low. The damage distribution extracted by discriminant analysis based on backscattering properties agreed with the results of an actual damage survey. Therefore, the images obtained by remote sensing SAR could be a powerful tool for post-disaster management.