An Improved Method of Precise Orbit Determination by Resetting Model Parameters

When using initial orbit elements with poor precision to calculate orbit elements of spacecrafts the model parameters (e.g.C_D which is about 2.2)estimated will be affected by the deviations in the initial elements,so that even if the RMS errors appear to converge the results of orbit do not converge to precise values.We give a method to reset the distorted parameters and also an example of its application to a satellite.A precise orbit-determination algorithm is used first to solve the conditional equations with the TLE as initial elements.The results are reset as the initial orbit elements for a new round of calculations,which converges to precise results.We further verify the method with the data of another satellite.The method thus has overall solved the problem that the calculation does not converge or converges to incorrect values due to the imprecise initial orbit elements.The RMS errors of the method reach the centimeter level.We show the RMS variation/distribution curves of two rounds of calculations,data use rates,and the results of orbit elements.