DEVELOPING SITUATIONAL CONDITIONS AND PROGRAM CODES FOR PARALLEL SITUATIONAL ANALYSIS SOLVER BASED ON CONIC UMBRA/SUNLIT MODELS.

The search for optimal time intervals for satellite operations performance is based on verifying specific conditions of a geometric or physical nature. Several conditions are combined in a situational problem. To be able to solve different situational problems, it is necessary to develop program codes for verifying different situational conditions in advance. Two situational conditions for determining if the satellite is in the sunlit zone or the umbra based on the conical models of the earth's shadow are presented. Necessary (but not sufficient) conditions are introduced to locate the satellite in the umbra or the sunlit zone, respectively. These conditions simplify the calculations and increase the computational efficiency for a large part of the satellite orbit. Problems with one or more conditions are solved by a developed parallel solver for situational analysis. Conditions checking the position of a satellite relative to the Earth's shadow can be combined with other situational conditions. A model of description of situational conditions is shown. [ABSTRACT FROM AUTHOR]