对地观测图像BRDF校准模型的建立与应用

The BRDF Model for the Calibration of Earth Observe Image

为提高对地观测图像质量的数据校准方法,建立区别于传统模型的对地观测目标复合双向反射分布函数(BRDF)模型.通过BRDF量值实现计量标准对该模型进行绝对量值标定,使得对地观测影像更真实反映观察对象.该模型综合考虑对地观测目标的BRDF分布、太阳辐射、大气分布状况等,加入BRDF国家计量标准的修正参量,结合遥感相机参数,得到计量校准后的遥感相机入瞳辐亮度数据.以一种典型建筑材料毛玻璃的BRDF测量及其对地观测图像的校准为例,通过这一复合模型的校准,其图像的色差提高约3,亮度对比提高约3.

Data calibration algorithm for the enhancement of earth observe image was presented. A new BRDF model of earth objects was established for the calibration of earth observe image by the national metrology equipment. Through BRDF absolute calibration, the earth observe image can be appeared more true. This model colligated the BRDF of earth objects, solar radiance, the atmosphere status, the correct parameter of BRDF calibration and the space camera parameter. The output data of this model is the enter radiance data for the space camera. A kind of ground glass for architecture is measured and the correspond earth observe image is calibrated. After calibration, the chromatism of this image is improved by 3 and the luminance contrast of that is improved by 3.