TM图像的光谱信息特征与最佳波段组合

本文分析了北自黑龙江省寒温带缓岗平原、南至广东省南亚热带丘陵等9个不同景观类型样区的TM图像数据,查明TM图像的光谱信息具3—4维结构,其物理含义相当于“亮度”、“绿度”和“热度”、“湿度”。在TM7个光谱图像中,一般以第5波段包含的地物信息最丰富。3个可见光波段(即第1,2,3波段)之间,两个中红外波段(即第5,7波段)之间相关性很高,表明这些波段的信息中有相当大的“重复性”或“冗余性”。第4,6波段则颇特殊,尤其是第4波段与各波段的相关性都很低,表明这个波段的信息有很大的独立性。计算20种组合的熵值的结果表明,由一个可见光波段、一个中红外波段及第4波段组合而成的彩色合成图像,一般具有最丰富的地物信息,其中又常以4,5,3或4,5,1波段的组合为最佳。

The Information Characteristics of Thematic Mapper Data and the Optimal Band Combination

In this article, TM image data covering nine sample areas of various landscape from the northern frigid temperate zone undulating plain to the southern subtropics hilly land one analysed and compared in many ways. The results indicate that the spectral information of TM image is essentially three to four demensional structure which physical meaning are match with Brightress, Greeness, Temperature and Humidity. In the seven TM bands, band 5 have the most ground information. There is the strong correlation between the three visible bands (band 1, 2, 3) and between the middle-infrared bands (band 5, 7), which indicate that there is very much "repeatability" or "redundacy" information in these bands. Between band 6 especially band 4 and the other bands is there very low correlation, which is shown that the information of the two bands is with very large independence. Computing twenty kind of combinations indicate that the color images by one of the visible bands, one of the middle-infrared bands and band 4 is generally with the most ground information, in which the combination of band 4, 5 and 3 or band 4, 5 and 1 is the optimal combination.