基于SDP4模型的导航卫星仰角及方位角预报

Navigation Satellite Elevation and Azimuth Prediction Based on SDP4 Model

地面站可控天线可以不借助接收机而直接监测导航卫星的信号质量,地面天线伺服系统根据卫星的实时位置计算出仰角及方位角来确定天线的指向。广播星历及历书等常用的计算卫星位置的方法虽误差较小,但其误差随时间迅速扩大,基于该问题,论文论述了双行星历(TLE)结合SDP4模型进行卫星轨道预报方法,利用SDP4模型计算GPS导航卫星的实时位置并预报卫星的仰角及方位角,采用IGS事后精密星历对其角度预报误差进行了评估,同时,还将该方法的预报误差与广播星历、历书、STK高精度轨道预报等方法的预报误差进行了对比.实验结果表明:采用SDP4模型对导航卫星进行位置预报可满足误差要求,且时间有效性长、通用性好,具备实际应用价值。

A high-gain steerable antenna allows direct signal measurements without the aid from a receiver .The real-time position of a satellite must be forecasted before the anten-na start tracking the satellite .Although the methods like broadcast ephemeris and almanac can determine the satellite position accurately ,the prediction error increases quickly .In this paper , the satellite positions were forecasted by Simplified Deep-space Perturbations-4 （SDP4） method ,and the two line elements （TLE） were utilized .The antenna pointing was determined by satellite elevation and azimuth .Hence ,the elevation error and azimuth error were analyzed .Moreover ,the errors of other methods like broadcast ephemeris ,almanac and STK High precision orbit prediction （HPOP） model were compared with SDP4 method . The result showed that ,not only the precision of SDP4 model can meet the required stand-ard ,but also this model can be durable .T herefore ,it is practical and applicable .