Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a star pattern recognition method and to a star sensor apparatus for determining spacecraft attitude, and more particularly, to a star pattern recognition method and to a star sensor apparatus using statistical data. According to the present invention, a star pattern recognition method for determining spacecraft attitude is provided, as well as a star sensor apparatus for the method, wherein said method comprises: an observation data acquiring step of acquiring statistical data for a first reference star in images of stars obtained from a star sensor of a spacecraft; and a pattern recognition step of searching the registered plurality of reference stars for one reference star having statistical data closest to the statistical data of the first reference star. The statistical data for the relevant star are statistical indices determined by coordinates on a standard coordinate system of stars in a region-of-interest containing said relevant star.