Simulation of Real-Time Orbit Determination Based on Lunar Relay Satellite by Angular and Ranging Measurements

Based on the concept of lunar relay satellite(LRS), it is envisaged that the use of a LRS measures the angle and the distance about the lunar probe executing mission in the low lunar orbit in order to carry out the real-time tracking and orbit determination by using the extended Kalman filtering(EKF) algorithm. under the two-body problem, this paper gives out the state model, the measurement model, the state prediction equation, the state transition matrix and the measurement Jacobi matrix. Simulations were designed and conducted. the results indicate that, by the angular and ranging measurement with the high accuracy of measurement, the algorithm converges very fast and also reaches a preferable performance in the accuracy of orbit determination, which prove that the existing target tracking and positioning method applied to the Moon is feasible and can achieve the high orbit determining accuracy.