摘要
长波授时具有覆盖范围广、信号传播稳定、抗干扰性能好的特点.长波授时的关键是精确计算长波信号在传播路径上的时间延迟.由于长波传播路径的复杂性以及气象条件的实时性变化,传统的时延预测方法难以实现较高的授时精度.借助于GPS信号,长波定时接收机可以间接获得较精确的传播路径时延.利用长波覆盖范围内相距不远的两接收点具有空间相关性以及传播路径上的电参数近似的特点,计算分析两接收点上传播路径时延的相关系数.在此基础上,提出了一种利用差分进行长波高精度授时的方法,该方法就是利用基准站上预报的差分改正数修正用户点上的传播路径时延.计算结果表明:差分修正后,传播路径时延的预测精度得到一定程度的提高,差分效果明显.这种长波差分授时计算方法可以有效利用传播路径上的公共误差,改善长波时延预测精度,提高长波的授时精度.
Long-wave timing has the characteristics of wide coverage,stable signal propagation,and good anti-interference performance.The key of long-wave high precision timing is to calculate the time delay on the propagation path of long-wave signal accurately.It is difficult to achieve high timing accuracy for the traditional time delay prediction method due to the complexity of long-wave propagation path and the realtime change of meteorological conditions.The long-wave timing receiver can indirectly obtain accurate propagation path delay with the help of GPS signal.The correlation coefficients of propagation path delay at two receiving points are calculated by using the characteristics of spatial correlation and the similar electrical parameters on the propagation path of two receiving points which are not far apart in the long-wave coverage range.The results show that the propagation path delays of two receiving points have an obvious correlation.On this basis,the method by using the difference to make long-wave high precision timing is proposed,which is to revise the propagation path delay at the user point by using the difference correction number predicted at the reference station.The calculated results show that the prediction precision of propagation path delay is improved,and the difference effect is obvious after the difference correction.The long-wave difference timing method can effectively use the public error on the propagation path,enhance the accuracy of long-wave delay prediction,and improve the timing accuracy of long wave.
作者
燕保荣
李云
郭伟
华宇
YAN Bao-rong;LI Yun;GUO Wei;HUA Yu(National Time Service Center,Chinese Academy of Sciences,Xi'an 710600;Key Laboratory of Precise Positioning and Timing Technology,Chinese Academy of Sciences, Xi'an 710600)
出处
《天文学报》
CSCD
北大核心
2018年第6期84-97,共14页
Acta Astronomica Sinica
基金
中国科学院前沿科学重点研究项目(QYZDJ-SSW-JSC034)资助
作者简介
燕保荣:yanbaorong@ntsc.ac.cn.
