Evaluation of Genetic Algorithms for Single Ground Station Scheduling Problem

Ground station scheduling problem arises in spacecraft operations and aims to allocate ground stations to spacecraft to make possible the communication between operations teams and spacecraft systems. The problem belongs to the family of satellite scheduling for the specific case of mapping communications to ground stations. Ground stations are terrestrial terminals designed for extra-planetary communications with spacecrafts. Spacecrafts are extra-planetary crafts including satellites, space stations, etc. The ground station scheduling problem is a highly constraint problem, among which, the most important is computing timing of spacecrafts communications with the ground stations. The problem can be seen as a time-window scheduling problem given that spacecrafts have their access window and visibility windows--visible time of a spacecraft to a ground station--are to be found avoiding the visibility clash among spacecrafts. The problem is indeed intractable and therefore it is unlikely to be solved in polynomial time to optimality. In this paper we evaluate the effectiveness of Genetic Algorithms (GAs) for near-optimally solving the problem. A data simulation model is used for the experimental study in order to realistically capture features of real instances and evaluate GAs for different scenarios. Computational results are given for the case of a single ground station. Through the experimental evaluation we could identify a set of parameter values that yielded the best performance of the GAs.