Modeling of spectroerergetic characteristics of space objects in the optical range

In connection with the emergence of abnormal situations at the stage of launching space vehicles (SV) for various purposes (AngoSat-1, Telkom-3, Phobos-Grunt, etc.), the problems of timely detection of such situations and remote monitoring of the technical condition of SV are of vital importance. To assess the feasibility of solving this class of problems with the use of optronic equipment (OE), it is necessary to have a priori information on the spectroenergetic characteristics (SEC) of a SV and associated backgrounds for the projected angles and conditions of observation in the operational spectral ranges of the OE taking into account the illumination by the Sun and the Earth. Due to the adapta- bility of mathematical modeling to the high degree of variability of the above factors, this method can be considered as a rational one for obtaining dynamic SEC (signatures) of SV for observation conditions that change during an or- bital flight. The technology of SEC modeling of space objects (SO) with the use of FemRad dedicated software (DS) is pre- sented, which provides the production of SO SEC taking into account the indicatrices of the scattering of optical radia- tion from materials and coatings of the external surface of the object, the dynamics of its thermal regime and the condi- tions of illumination by the Sun and Earth during the orbital flight. The advantage of the presented technology is the compatibility of the developer’s own software solutions with the widespread application programs of finite element analysis. In particular, the known CAD and CAE tools - SolidWorks, ANSYS, Gmsh - are used to develop grid geometric 3D models of SO. The method for parametric approximation of the measured indicatrices of scattering of optical radiation from mate- rials and coatings of SO on the basis of a given model of roughness is considered. The main provisions of the DS meth- odology for calculating the heat flux of the “Earth-atmosphere” system, as well as the fluxes of reflected and scattered solar radiation falling on the SO in the range 0.2-20 µm, are presented. The results of modeling the dynamic SEC of a typical SO in the infrared (IR) range are given as an illustration of the application of the DS.