Software and Methodological Support for the Operational Calculation of Solar Energy Absorbed by the Underlying Surface, Based on Satellite Data

The article proposes a method for calculating the solar energy absorbed by the Earth's underlying surface for any arbitrarily chosen territory, based on the use of satellite monitoring data stored in the information base of the NASA EOS project in the form of HDF4 files. The proposed technique allows for a given geographic point and a given observation time to take the necessary data directly at the source of their formation and perform all subsequent processing and calculation procedures in automatic mode. This article provides a list of HDF files required to perform calculations, describes their structure, how to find and extract them from the EOS database, as well as an algorithm for extracting all the necessary data from these files using the Java helper libraries and the LAADS DAAC API. The article also presents the structure and interface of a software package that allows you to download the necessary files in accordance with the specified search criteria, extract the necessary data from them, and calculate the solar energy absorbed by the underlying surface at a given point. The calculation is based on the method of supporting spectra, according to which the model of the propagation of solar radiation in the atmosphere is a sequence of linear transformations of its spectrum with using helper spectra, corresponding to various stages of the passage of light through the atmosphere, its absorption by the earth's surface and reflection from it. This method, in contrast to the Modtran simulator, does not require a large amount of computational resources due to the fact that it uses fairly simple polynomial approximation functions and pre-calculated reference spectra used in transformations. To perform calculations by the method of supporting spectra, the software package includes an auxiliary package written in the Scilab programming language. The use of the proposed computing technology made it possible to carry out daily processing of data received from a satellite using a conventional personal computer, without involving powerful computing clusters to perform calculations.