基于DEM的地形辐射校正模型的研究

在地形复杂的地区,地形校正是影像预处理的一个重要步骤。它不仅能提高遥感识别与分类的精度,还是各种定量化遥感应用的前提。本文以2002年延庆县的ETM+为数据源,采用了余弦、SCS、C、SCS+C和CIVC0等五种不同的校正模型进行了对比分析研究。结果表明,5种方法均能在很大程度上消除地形阴影,更好地反映阴影区域的细节信息;从总体的光谱特性保真程度来说,余弦和SCS校正都因过度校正问题表现较差,C校正也表现一般。CIVC0校正和SCS+C校正光谱特性保持较好,但SCS+C校正也存在过度校正问题,CIVC0校正有点校正不足,但相比较CIVC0校正效果更好点。

Topographic correction methods for DEM based remotely sensed imagery in mountainous areas

The process of topographic normalization may be critical in areas of rough terrain, as a preliminary step to the remote sensing image. It not only improves the classification accuracy but also is a prerequisite in any quantitative remote sensing with high preciseness approach. Five Topographic correction methods（cosine. C, SCS. SCS＋C. CIVC0） were tested by a ETM＋ image which received in 2002 year in a rugged area of Yanqing County. It turned out that the five different topographic corrections can remove topographic effects successfully and restore the land-surface information in shadow areas effectively; in terms of the preservation of spectral characteristic, the cosine and SCS models encounter the overcorrection problem, the C correction manifest ordinarily, the CIVC0 correction and the SCS＋C correction do well in preserve spectral characteristic, however, the SCS＋C correction exists little overcorrection problem and the CIVCO correction in opposite, in comparison, the CIVC0 correction shows smoother in spectral characteristic.