Fitting Accuracy Analysis of Satellite Coordinate Based on BDS Broadcast Ephemeris

Aiming at the question of repeated calculations and low efficiency when calculating satellite positions using the broadcast ephemeris,this paper proposes the use of Chebyshev polynomials to fit satellite orbit for broadcast ephemeris by calculating the satellite coordinates of some fixed time intervals as known nodes. Using different fitting orders to find difference between the fitting point and the corresponding point obtained by the direct method and analyzing the fitting accuracy.The examples show that the broadcast ephemeris fitting accuracy can meet the requirements as long as the fitting time interval and the fitting order are taken properly.