Simulation of atmospheric brightness distributions from a visible earth sensor using MODTRAN4

Due to the scattering and reflection of the terrestrial atmosphere, especially when there are clouds or any different geographical circumstances, the visible earth sensor on the satellite will receive changing atmospheric radiation. Therefore, the images received by the detector of visible earth sensor will have fuzzy boundaries, thus affecting the measurement accuracy of geocentric vector. In order to eliminate the impact of the existence of the atmosphere in the Sun-Earth-Sensor path on earth sensing imaging, the emphasis of our study lies on the issue of atmospheric brightness distributions. Firstly, we briefly discuss the influence factors of atmospheric brightness at the visible earth sensor, using the atmospheric radiation transfer model MODTRAN4. Then, by running MODTRAN4 under a specific physical model, we successfully acquire both graphs and numerical results of the atmospheric brightness distributions in the full field of view of the visible earth sensor under different circumstances. Based on the research of this paper, given the specific structure and parameters of the detector of earth sensor, calculating the illumination intensity on the image plane is possible.