摘要
为了提高全球导航卫星系统(GNSS)的信号捕获速度,提出了一种校正与补偿由卫星运动导致的GNSS信号中的多普勒频移的算法。讨论了由卫星运动的动力学方程计算卫星运动速度的方法、(GNSS接收机位置下的)可见卫星的确定,分析了由卫星运动引入GNSS信号中的多普勒频移,通过建模仿真了24颗卫星信号的多普勒频移变化曲线。仿真结果表明,多普勒随时间变化的曲线是具有周期性和单值性的光滑曲线,可依据接收机时钟估计出多普勒频移值,在半径800 km左右的范围内,大部分时间上的估计误差小于500 Hz,有效地缩减了多普勒频移的不确定范围,提高了GNSS信号的捕获速度。
In order to improve the signal acquisition speed of the Global Navigation Satellite System （GNSS） ,a new algorithm is proposed to correct and compensate the Doppler shift in GNSS signal caused by the motion of satellites. The method of calculating satellite velocity via the dynamic equation of satellite motion,and the determination of visible satellites under the position of the GNSS receiver are discussed.Then the Doppler shift in GNSS signal introduced by satellite motion is analyzed.The curve of the Doppler shift in 24 satellite signals changing with the time is analyzed by computer simulation. Simulation results show that the Doppler shift curve varying with the time is a smooth curve with periodicity and the monodromy.And Doppler frequency shift value can be estimated just on the receiver clock.Within a range of 800 km,the estimation error is less than 500 Hz in most case.So,our new algorithm can effectively reduce the range of Doppler frequency shift and improve the acquisition speed of GNSS signal.
作者
高法钦
夏海霞
GAO Fa-qin XIA Hai-xia(School of Information Science, Zhejiang Sci- Tech University, Hangzhou Zhejiang 310018, China)
出处
《无线电工程》
2017年第4期39-43,82,共6页
Radio Engineering
基金
国家自然科学基金资助项目(61402417)
浙江省自然科学基金资助项目(LY14F030025)资助
