【摘要】 数字摄像仪测量白天能见度过程中,由于目标物的非黑体特性、天空亮度分布不均匀性和遮挡物的存在,造成常用的双亮度差方法不能准确计算能见度。为此设计了一种新的基于数字摄像机的白天能见度算法:将数字摄像机获取的彩色图像分割后留下背景天空区域,对目标区域进行天空信息重建,通过估计透射率计算能见度值。实验数据表明,该算法在能见度观测范围1 500～3 000 m内最大误差小于20%,符合世界气象组织对能见度仪的误差要求,并在天空亮度分布不均匀并存在遮挡物的情况下得到良好的观测结果,测量结果比双亮度差方法误差减小2.4%～3%。更多还原

【Abstract】 In the process of measuring daytime visibility by digital camera,because of the characteristics of non-blackbody of object,uneven distribution of the sky brightness and the existing of obstruction,the common dual differential luminance method can not calculate the visibility accurately.Therefore,a new daytime visibility algorithm based on digital camera is designed in the paper.The background sky area after segmentation of color image captured by digital camera is left,and then the sky information of the target region is rebuilt.Finally,the visibility is calculated using estimated transmission.The experimental data show that the maximum error of the algorithm is less than 20% in the visibility observation range of 1 500~3 000 meters,and it satisfies the requirement of WMO for the error of visibility instrument.Also it obtains good observation result at uneven distribution of brightness in the sky and existing of obstructions,the error of measurement result reduces 2.4%~3% compared with dual differential luminance method.更多还原