广义延拓法在GPS精密星历内插和外推中的应用  

Application of Generalized Continuation Method in Interpolation and Extrapolation of GPS Precise Ephemeris

作　　者：陈强强[1,2] 陈志平 李芳[2] 

机构地区：[1]杭州电子科技大学机械工程学院,浙江杭州310018 [2]中国科学院国家天文台,北京100012

出　　处：《天文研究与技术》2018年第1期52-58,共7页Astronomical Research & Technology

基　　金：国家自然科学基金(61601009)资助

摘　　要：利用精密星历解算卫星坐标是实现全球定位系统高精度差分定位的首要基础,受限于全球定位系统精密星历的采样时间间隔,为了得到任意时刻的卫星坐标,需要对全球定位系统精密星历数据做内插和外推处理。分析卫星位置随时间变化的规律后,采用广义延拓法对卫星的一段轨道构造以时间为坐标的内插和外推模型,在不引入较大位置误差的同时简化了卫星坐标的计算过程,并与拉格朗日插值法进行对比实验。研究结果表明,利用广义延拓法内插时误差小于5 cm,且在外推30 min内仍然能维持精度,明显优于拉格朗日插值法。Using precise ephemeris to solve satellite coordinates is the primary basis for high precision differential positioning of GPS. In order to obtain satellite coordinates at any time since the GPS precise ephemeris has limit of the sampling interval, it is necessary to interpolate and extrapolate GPS precise ephemeris data. After analysis on the regularity of satellite position changing with time, the interpolation and extrapolation model which is relative to time is built by generalized extension method, and it is used to describe a section of satellite orbit, the calculation process of satellite coordinate is simplified without introducing comparatively larger position error through this method, which is then compared with the Lagrange interpolation method in experiment. The result shows that the error of interpolation when using generalized extension method is less than 5cm, and the accuracy of extrapolation maintains 30 minutes, which is significantly better than the Lagrange interpolation method.

关 键 词：精密星历 插值 外推 广义延拓 全球定位系统 

分 类 号：P228.1[天文地球—大地测量学与测量工程]