Landsat-5遥感卫星波段组合与比值分析在汶川地震前后的应用

文章在遥感图像处理软件ENVI的支持下，以汶川地震的极重灾区汶川县为研究区，选取2007年、2008年和2010年这3个时期的Landsat-5 TM数据为数据源，提取分析了地震前后TM数据的相关信息。利用相关系数矩阵、特征向量和特征值，按照最佳波段组合原则，对地震前后的TM影像进行了多种波段组合试验和比值分析。经分析得出以TM3、TM4、TM5波段组合为基础，参考其他组合（如TM1、TM4、TM5，TM4、TM2、TM7和 NDVI、TM5/TM3、TM4/TM3的组合）容易解译和判读 TM遥感影像的相关地物数据类型，为地震解译和灾害评估提供了理论依据和支撑。

Application of Band Combination and Ratio Analysis about Landsat-5 Satellite before and after Wenchuan Earthquake

With the support of ENVI（The Environment for Visualizing Images）that is a kind of remote sensing image processing software, the paper takes Wenchuan region as a research region which is the most serious area in Wenchuan earthquake. It selects three different periods of Landsat-5 TM data in the year of 2007, 2008 and 2010 and calculates the relevant statistical information respectively. It carries out all kinds of band combination test and ratio analysis based on TM remote sensing images before and after Wenchuan earthquake, by using correlative coefficient matrix, covariance and correlation, according to the principles of the best band combination. The conclusion is that based on the combination of TM bands（4, 3, 5）and has the reference with other combinations（such as TM1, TM4, TM5;TM4, TM2, TM7 and NDVI, TM5/TM3, TM4/TM3 combina-tions）as references, it is easy to interpret the types of features of TM image and the change of features, which can provide the convincing theoretical basis and support for seismic interpretation and disaster assessment.