摘要
针对考虑太阳直接辐射、天空散射辐射以及来自于附近地表反射辐射的复杂地形EMT+遥感影像地形校正物理模型公式复杂、计算繁琐、不易实施的特点以及存在过度校正的缺陷,对该物理模型进行简化和改进。提出一套简化模型相关参数,即r值,Vt,Vd,T↓(λ,θ)等的计算方案,从而简化计算过程,提高计算效率。并针对该地形校正物理模型朗伯体假设的缺陷,引入Minnaert参数k时模型进行非朗伯体修正。简化和改进的地形校正物理模型的校正实验结果表明该模型很好地消除了复杂地形EMT+遥感影像的地形阴影,从而证明该地形校正物理模型的简化和改进方案可行。
Aiming at the shortcomings of the physical algorithm for topographic effect removal on remotely sensed data, such as formula complicated, computation difficult and uneasy operation, etc, the modification for simplifying the algorithm was proposed to take solar direct irradiance, diffuse sky irradiance and reflected irradiance from adjacent surface due to direct and diffuse irradiance into account. The original physical algorithm was developed with the assumption that the surface is Lambertian which results in over corrections to the image. The simplification and modification of the original algorithm was mainly concentrated on the simplified calculation of the parameters r value, Vt, Vd and T↓ （λ,θ） under the non Lambertian assumption of the terrain surface by introducing the Minnaert constant k as a BRDF parameter to describe the non Lambertian reflectance behavior of surface. The simplified and improved algorithm was applied to a selected Landsat TM image acquired from a complicated terrain surface, the results showed that the algorithm efficiently reduces the topographic effect of ETM ＋ image from rugged terrain, and the algorithm is proposed valid and feasible.
出处
《测绘学报》
EI
CSCD
北大核心
2008年第1期89-94,120,共7页
Acta Geodaetica et Cartographica Sinica
基金
国家重点基础研究发展规划项目(2006CB400502)
中科院“百人计划”择优支持项目(8-057493)
关键词
复杂地形
ETM+
地形校正物理模型
简化
改进
rugged terrain
ETM ＋
physical topographic correction algorithm
simplification
modification
