地质灾害调查中ETM+与SPOT-5 Pan融合方法比较

ETM+与SPOT-5Pan融合影像含有丰富的光谱信息和空间结构信息,是地质灾害调查的理想数据源。但ETM+多光谱图像与SPOT-5 Pan图像空间分辨率相差悬殊,直接融合可能导致融合影像色彩模糊、色调不和谐等问题；若将ETM+与其全色融合后再与SPOT-5 Pan融合,如果融合方法不当亦会造成光谱信息的过多损失。通过采用IHS、Brovey、PCA和Gram-Schmidt变换分别对ETM+和SPOT-5 Pan按上述两种途径进行直接和间接融合,采用主观评定以及光谱剖面分析对融合影像进行了评价,从而筛选出适合于地质灾害调查的ETM+与SPOT-5 Pan融合方法。

A Comparison of Fusing Methods of ETM+ and SPOT-5 PAN Images for Geohazrd Detection

The fused image of ETM+ and SPOT-5 Pan is a suitable data source for geohazard detection because it has abundant spectral and spatial textural information.However,the spatial resolution of SPOT-5 Pan is much higher than that of ETM+ multi-spectral images,a suitable fusing method should be selected to fuse SPOT-5 Pan with ETM+ images to obtain a fused image with high spatial and spectral resolutions.In this paper,a comparison has been made using various fusing methods,including IHS,Brovey,PCA and Gram-Schmidt transformation methods.Subjective appraisal and horizontal spectral profile have been adopted to assess the quality of the fused images.It is concluded that PCA and Gram-Schmidt transformation methods are suitable for fusing SPOT-5 Pan and ETM+ images,and that it would be better for ETM+ spectral bands to be fused with ETM+ Pan image,and then fused with SPOT-5 Pan image.