Optimum Space Systems Ground Complex Elemnts Network Selection Method

Abstract

After launch, access to space segment (the satellite) and space operations can be done only by means of the ground segment and its radio link between satellite and TT&C ground stations; so the preliminary activities must be fulfilled before. In this article, the three main methods of satellite contro l during flight have been introduced and the optimum method has been concluded. The main methods of satellite control are: command-based, time schedulebased and coordinatebased control method; the other methods are combinations of these three methods. In order to determine the optimum one, the AHP (Analytic Hierarchy Process) method has been used. All the satellite control methods have advantages and disadvantages so the mission planners and system engineers will select the best, according to the criteria and the weight of each criterion. The satellite onboard computer (OBC) will be programmed based on the selected control method. The supposed criteria in this article are: fastness (the time interval between decision making and start-up), accuracy, cost, onboard power consumption and reliability. Among the introduced methods, the combination of commandbased and time schedulebased control method has been selected as the optimum.