Abstract

An algorithm for estimating the range of influence of broken cloudiness on the results of retrieving reflectance of cloudless Earth surface regions is proposed for satellite observations through gaps in a cloud field. The algorithm is based on the Monte Carlo method of simulation of radiation transfer in broken stochastic cloudiness with averaging over the cloud field. Two models of cloud fields are considered: the field shapes as parallelepipeds and paraboloids. The method is tested for two fragments of the real MODIS image with the coordinates of 53.4°–56.4° N, 109°–115° E and 49.0°–51.0° N, 121°–123° E. The results of computations show that the effect of cloudiness is significant at distances up to 25 km for the first image fragment and up to 5–7 km for the second one.

中文翻译：

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从 MODIS 图像反演无云地表区域反射率的碎云效应估计

摘要

针对通过云场间隙进行卫星观测，提出了一种估计破碎云量对无云地表区域反射率反演结果影响范围的算法。该算法基于蒙特卡洛方法模拟破碎随机云量中的辐射传输，并在云场上取平均值。考虑了两种云场模型：平行六面体和抛物面的场形状。该方法对真实 MODIS 图像的两个片段进行了测试，坐标分别为 53.4°–56.4° N、109°–115° E 和 49.0°–51.0° N、121°–123° E。计算结果表明：在第一个图像片段的距离高达 25 公里，第二个图像片段的距离高达 5-7 公里时，云量的影响是显着的。