多时相阴影轮廓差分辅助下的城市水体提取

如何避免水体提取中阴影信息与水体信息的混淆,是利用遥感数据提取城市水体信息需要解决的一个问题。本文以高分一号WFV图像及Landsat8 OLI图像为数据源,利用阴影轮廓的位置与形状在不同太阳高度角及太阳方位角下的差异性,提出一种基于多时相阴影轮廓差分的城市水体提取方法(WMSD)。以广州市天河区为试验区进行水体信息提取,同时运用NDWI、MNDWI及SWI指数法分别提取水体信息,进行精度对比分析。结果显示,本文所提出的WMSD方法分类精度超过88%,较NDWI法、SWI法及MNDWI法的水体提取精度分别提高了8.50%、9.50%及4.67%。说明基于阴影轮廓位置与形状的差异提取水体信息的方法能够较好地解决阴影与水体提取信息混淆的问题,为利用遥感数据提取城市地区水体提供了一个可行的处理方法。

Urban water body information extraction base on the multi-temporal contour shadow difference

How to solve the problem of water and shadow mixing in urban area is important but difficult.However,the difference between the position and shape of the shadow contour at different time provide a potential way to solve this problem.The objective of this study is to propose a method of urban water body information extraction base on the multi-temporal shadow contour difference (WMSD).Two remote sensing images of GF-1 and Landsat 8 were used to test this propose method in Tianhe District,Guangzhou.At the same time,we used some methods of NDWI,MNDWI and SWI to extract water information in this same area,and carried out precision comparative analysis.Study results show that the classification accuracy of WMSD is over 88%,and compared with NDWI,SWI and MNDWI methods,the accuracy of WMSD increase by 8.50%,9.50% and 4.67% respectively,which proves that the WMSD method can solve the problem of the confusion between the shadow and the water extraction information,and can be a feasible method for the extraction of urban water body by remote sensing information.