Ephemeris / attitude reference determination system using on-board optics and other satellite ephemeris

摘要

The present invention provides a system (200) for determining the ephemeris and attitude for a spacecraft based on optical payload pointing directions and the ephemeris of other spacecraft. An ephemeris determining subsystem (300) obtains ephemeris data (308) for one or more reference spacecraft. Optical payload pointing information (306) is obtained for the optical payload pointed to the reference spacecraft. The spacecraft ephemeris (312) is then calculated with ephemeris determination algorithms (302) based on the ephemeris data (308) and optical payload pointing information (306). Other available information, such as stored results of previous measurements and calculations, time (310), spacecraft attitude (304), information from non-payload sensors and ranging information may be used to enhance the accuracy or decrease the complexity of the ephemeris calculations. In addition to ephemeris determination, the present invention also provides an attitude determining subsystem (800) for the determination of spacecraft attitude (810). Ephemeris data for reference spacecraft (806) and optical payload pointing information (802) is obtained. The spacecraft attitude is then calculated by attitude determination algorithms (804) based on the ephemeris of reference spacecraft (806) pointed to by the optical payload and the optical payload pointing information (802). Other available information, such as stored results of previous measurements and calculations, time (808), information from non-payload sensors, and ranging information may be used to enhance the accuracy or decrease the complexity of the attitude calculations. IMAGE