Modeling the illumination of the Earth’s surface to select the operating modes of the radiation source

An approach to obtain light-signal characteristics in graphoanalytical form is proposed to substantiate the operating modes of the emitting equipment of active optoelectronic complexes of remote sensing of the Earth. These complexes are used for shooting in conditions of insufficient natural illumination of the terrain due to the difficult terrain, geographical location of the area or the low position of the Sun above the plane of the local horizon. Using the presented model, calculations of the energy illumination of the Earth's surface were carried out, dependencies were constructed that take into account the influence of the position of the Sun above the local horizon plane for specific dates and daily time on the distribution of the spectral density of the electromagnetic radiation flux. Light-signal characteristics have been obtained, which can be used to justify the operating modes of the emitting equipment of active optoelectronic complexes. Based on these characteristics, it is concluded that it is necessary to artificially enhance the spectral density of the radiation flux in a given range of the spectrum in order to achieve the required illumination of the photographed area of the Earth's surface for a specific date and time. The amplification of the spectral density of the radiation flux makes it possible to create the exposure required for the formation of images with high visual properties. The simulation results are used in the problem of predicting the quality of images obtained using artificial sources of optical illumination. The proposed approach makes it possible to obtain images characterized by the high value of linear resolution on the ground, without resorting to increasing the charge accumulation time by the photodetector of the recording equipment. The application of this approach is particularly relevant in the conditions of conducting aerospace surveys.