利用广播星历计算GPS卫星位置及误差分析

Calculation and error analysis of GPS satellite position by making use of broadcast ephemeris

为了提高GPS卫星轨道计算的精确性和实时性,通过对GPS卫星的广播星历进行分析,利用从广播星历中获取的开普勒轨道参数和轨道摄动修正项,以2005年11月6日的R INEX格式的广播星历为例,通过编程,计算了07号卫星当天24 h的轨道位置坐标,并将其与当天的精密星历所提供的卫星轨道位置坐标进行对比,并对广播星历的轨道精度进行初步的讨论。结果表明,该方法确实提高了GPS卫星轨道位置坐标计算的精度。利用广播星历计算GPS卫星位置的误差主要是由于时间外推方法造成的。

To improve the accuracy and real-time of the GPS satellites orbits calculation, the Kepler parameters and orbital amendatory parameters obtained from the GPS broadcast ephemeris were analyzed. With the format of the RINEX broadcast ephemeris in November the sixth 2005 as an example, the coordinate of the GPS satellite position of the number 07 was calculated, the result compared with the precise ephemeris supplied by IGS, and the accuracy of the orbit of the broadcast ephemeris discussed preliminarily. The results show that this method improvs the GPS satellite orbital positions coordinate calculation accuracy, and the errors calculated by making use of the broadcast ephemeris are caused by the method of extrapolation of time.