INITIAL ORBIT DETERMINATION METHOD OF GEOSYNCHRONOUS TARGET BASED ON OPTICAL DATA

There are two main objectives to determine the initial orbit of space target. One is to provide the initial value for the target precision orbit determination, and the other is to provide the initial value for the correlation of the target observation data. Its importance is self-evident. According to the orbit characteristics of the geosynchronous orbit target, it remains relatively stationary relative to the station during observation arcs. Due to the lack of ranging constraints, when using the optical angular measurements based on short arcs to calculate the orbit by the traditional Laplace method, most iterative processes diverge due to the ill-condition of the observation condition, and it is difficult to obtain the converged result of the initial orbit. For these reasons, this paper adopts the method of orbit semi-major axis traversal search, that is, it introduces pseudo range based on the given semi-major axis into initial orbit determination to supplement the range constraints. Using the simulated data to determine the initial orbits, the success rate of the method is better than 95%. It effectively solves the difficult convergence problem for the near-circular orbit target in geosynchronous orbit zone during the iteratively calculating of the initial orbit process.