http://www.gissky.net- GIS空间站

本文对新近提出的增强型水体指数(EWI)进行了分析和讨论,分别用经过大气校正和未经大气校正的两种影像来对该指数作了验证,并与改进的归一化差值水体指数(MNDWI)进行比较。结果表明该指数在经过大气校正的影像中对水体的增强和提取效果不理想,许多水体影像特征不但未能得到增强,反而受到抑制而被漏提。显然,该指数在创建时忽略了大气因素的影响。另外,该指数在构建上重复选择近红外和中红外波段也是造成提取效果不理想的原因之一。因此,为了创建正确的水体指数,避免水体增强和提取结果的偶然性和不确定性,水体指数的创建必须用经过大气校正的影像进行验证,而构建指数的波段也要避免不合理的重复选择,这样才能使所创建的指数具有更广的适应性。 更多还原

【Abstract】 This paper analyzes a newly proposed remote sensing index—the Enhanced Water Index(EWI),by Yan et al.(2007) and discusses the creation of a water index.The EWI was constructed by the ratio of the green light band to the sum of the near infrared(NIR) band and midddle infrared(MIR) band,i.e.,EWI=[(Green-(NIR+MIR))/[(Green+(NIR+MIR)).The evaluation of the EWI was through the application of the index in two images,one without atmospheric correction and the other with the atmospheric correction,and t... 更多还原