Spacecraft communication sessions scheduling by ground-based sensors with instant transitions between objects

The paper considers the problem of planning space-to-ground communication sessions with the aim of obtaining the required amount of information from each object. It is assumed that the time required to switch between spacecraft is negligible. Examples of ground-based sensors with instant transitions between objects are radio stations with phased antenna arrays. A model for determining visibility intervals is described. The model takes into account the geometric and energy parameters of visibility. A mathematical model of planning is presented in the form of a nonlinear programming problem. In this case, the objective function optimises not the duration of communication sessions, but the amount of information transmitted. The article presents the results of a numerical experiment for three algorithms: an optimisation algorithm, an algorithm based on uniform division of the visibility interval (the basic algorithm) and an algorithm based on the random walk method (the random algorithm). The numerical experiment was conducted for a group of Earth remote sensing (ERS) satellites from Planet Labs company. The experiment shows that the use of the optimisation algorithm allows the required amount of information to be obtained for each spacecraft for a group of about 135 objects. In addition, for a group of about 175 satellites, the optimisation method improves the metric value by 16% compared to the basic algorithm and by 20% compared to the random algorithm.