切比雪夫多项式拟合GPS卫星星历精度分析

摘要

采用切比雪夫多项式拟合GPS精密星历，节点的选择对精度产生一定的影响。利用IGS提供的3种精密星历（最终星历－IGF、快速星历－IGR、超快速星历－IGU）分析随机选择插值节点和选择切比雪夫点拟合轨道的精度差异，并比较3种星历拟合轨道和IGS提供的轨道差值，分析其精度，结果表明采用切比雪夫点对精密星历进行拟合，最终星历和快速星历可以达到mm级，超快速星历由于其自身带有的误差较大，内插的精度也可达到cm级，证明运用切比雪夫点拟合精密卫星星历方法可行可靠。%As Chebyshev polynomial fits GPS precise ephemeris ,there is a certain impact on accuracy when choose node .Analyze the interpolation fitting precision in orbit of using randomly selected nodes and Chebyshev nodes to fit three kinds of precise ephemeris ( IGF,IGR,IGU) ,which IGS provides .And compare the difference between the three fitting ephemeris and IGS provided ephemeris ,analyze its accuracy ,the results show that the use of Chebyshev points for precise ephemeris fitting,IGF’s and IGR’s accuracy can reach mm level,IGU’s accuracy can reach cm level,prove the method,use Chebyshev ndes to fit precise ephemeris ,is feasible and reliable .