Satellite Tracking System Using Amateur Telescope and Star Camera for Portable Optical Ground Station

A portable optical ground station can track a satellite with an amateur telescope mounted on a two-axis gimbal. The telescope is aligned with respect to an inertial, Earth-fixed frame using a wide field of view star camera. Star cameras are accurate to the arcsecond level and have the advantage of providing orientation with a single measurement. Using multiple star sensor measurements at different gimbal angles, it is possible to calculate the alignment of the gimbals in the Earth-fixed frame and the alignment of the star sensor in the gimbal frame. Once the alignment is obtained, satellite tracking can be achieved with a known orbit and precise Earth rotation model, such as the International Earth Rotation and Reference System Service (IERS). This alignment procedure can be carried out in less than one hour, making it practical to move and deploy the portable ground station.