Satellite autonomous navigation algorithm analysis based on broadcast ephemeris parameters

Abstract

At present, the satellite on-board processing and transmission capacity of autonomous navigation is not enough to support the traditional centralized dynamic navigation algorithm. In order to augment the possibility of centralized onboard processing, this paper puts forward a centralized kinematics orbit determination method which is based on the long term broadcast ephemeris. This method directly calculates broadcast ephemeris corrections using inter-satellite observations, and executes in earth fixed coordinate without EOP parameter supports. The orbit results have no error accumulation. Compared with traditional processing mode, the orbit determination and ephemeris fitting steps are fitted into one step, and the orbital integral is omitted, so the amount of calculation could be effectively reduced. The experimental results show that the data sampling interval can be broadened to 20 min in a 4 h arc. This result could effectively reduce the requirements of satellite measurement and data processing frequency in autonomous navigation. Based on the current precision of 60 d long term orbit forecasting, this method can meet the orbit determination precision of URE 1 m and three-dimensional position 3 m. So it offers the possibility to achieve the on-board centralized autonomous navigation processing.