Simulation of satellite motion for intra-satellite pointing, acquisition, and tracking

A simulation in inertial coordinates of the motions of two satellites in low Earth orbit is presented. This simulation is used in a satellite cross-link pointing, accuracy, and tracking study. The simulation allows for arbitrary selection of inclination angles, altitudes, and other initial conditions. The simultaneous simulation of two satellites in different orbits produces data on the relative distances between the satellites in inertial coordinates, the rates of change of these distances, the angles swept out by the satellites´ motion, and the rates of change of these angles. Visibility regions and times are also calculated. Cross-angle, the angle between the satellite´s last antenna direction and the present vector to the other satellite, is also calculated. The cross-angle rate indicates the required speed of the satellite´s pointing system for an undisturbed cross-link.<>