MODTRAN模型在HJ／CCD影像大气校正中的应用

摘要

大气校正是定量遥感研究中必不可少的过程。本研究利用MODTRAN模型对一景HJ／CCD影像进行大气校正，并从典型地物光谱特征变化、校正结果与MODIS地表反射率产品比较及对归一化植被指数（ NDVI）的影响3方面评价校正效果，结果显示：MODTRAN模型较好地消除了可见光波段内的增加效应和近红外波段的吸收作用；校正结果与高精度的MODIS地表反射率产品在植被、居民地、水体3类地物的反射率具有较高的一致性，其中植被类型平均误差为12．8％；MODTRAN模型较好地修正了混合像元的NDVI值，校正后各类地物的NDVI均有所提升，其中植被NDVI的增幅最大，有利于区分植被与其他地物类型。表明MODTRAN模型对HJ／CCD影像具有较好的大气校正效果。%Atmospheric correction is an indispensable process in quantitative remote sensing research. In this study, MODTRAN model was used for the atmospheric correction of one HJ/CCD image, and the effectiveness of correction was e⁃valuated based on the spectral characteristics of typical ground objects. The results showed that atmospheric correction elimi⁃nated the increase effect in visible band and the absorption in near infrared band. The reflectivities of vegetation, water and residents achieved by MODTRAN atmospheric correction were in accordance with those by MODIS surface reflectance prod⁃uct, with the average error being 10%-25%. The NDVI of each kind of ground objects was improved, among which, vege⁃tation NDVI got the biggest increment, which was helpful to differentiate vegetation from other ground objects.