基于水质类型的TM图像水体信息提取

通过对一般水体、富营养化水体和严重污染水体与山体阴影在TM各波段图像上的亮度值进行分析比较可知:一般水体在TM4图像上的亮度值小于TM3波段的,而山体阴影则相反；由于富营养化水体中的浮游植物在TM4波段具有强反射特征,严重污染水体对可见光具有强吸收作用,造成了这两类水体在TM4图像上的亮度值大于TM3波段的,因而无法通...

The Extraction of Water Body Information from TM Imagery Based on Water Quality Types

The lightness values of three types of water,i.e.ordinary,eutrophic and seriously polluted,and vegetation in the shadow of the hill were analyzed in this paper.The results show that the lightness value of TM4 is lower than that of TM3 for ordinary water,whereas things are opposite for vegetation in the shadow of the hill;the eutrophic water contaminated by phytoplankton has strong reflection in TM4,and seriously polluted water has strong absorption in visible band,which the lightness value of TM4 is higher than that of TM3.Thus the eutrophic and polluted water couldn’t be distinguished from vegetation in the shadow of the hill by comparison between TM3 and TM4.According to the extraction method of classification of water quality type the spectral characteristics of the water,the authors set up the thresholds to distinguish various types of water quality,vegetation in the shadow of the hill and other ground objects,and extracted the water distribution information from TM imagery quickly,accurately and efficiently.