摘要
导航电文包含卫星导航系统中定位解算的基础数据,卫星轨道的计算精度与导航电文中广播星历参数的精度密切相关。电文帧结构中排布的各星历参数量化位数受限于电文传输的信息速率,需要进行详细的设计论证。本文首次专门分析和大量仿真了GPS导航电文中由星历参数的有限量化字长引入的误差对卫星位置计算精度的影响,并通过GPSL1C/A数字中频信号模拟器和软件接收机进行了闭环测试,结果表明NAV格式星历参数量化前后卫星位置的计算偏差在2h的星历有效时间内不超过0.2m;进一步的仿真分析表明其所引入的UERE(用户等效距离误差)偏差不超过0.06m,而对用户定位结果的影响在厘米量级。
Navigation messages contain essential data for position solution in satellite navigation system.The accuracy of the satellite (SV) orbit calculation is closely related to the accuracy of the broadcast ephemeris parameters in navigation message.This paper analyzes the orbit accuracy of SV affected by ephemeris parameter quantification of GPS navigation message,the results show that the satellite position calculated by the ephemeris parameters before and after the quantification within the two hours started at the Toe moment will be not more than 0.2m.By using the GPS L1C/A software simulator and software receiver for closed-loop testing,the simulated satellite position deviation is also less than 0.2m.When making the projection to the pseudorange direction,the maximum deviation is 0.06m.And the effect on the result of the user positioning is in the centimeter magnitude.
出处
《导航定位学报》
2013年第1期61-66,共6页
Journal of Navigation and Positioning
关键词
GPS
导航电文
星历参数
量化
卫星位置
GPS
navigation message
ephemeris parameters
quantification
satellite position
