长波信号中周期修正项对授时精度的影响

周期修正项是长波授时信号的一个特征量,它通常与长波授时信号的跟踪点有关。在授时过程中,它是影响长波传播路径时延计算的重要因素。讨论了长波定时信号接收端感应电动势周期修正项与发射端电流信号周期修正项的不同,分析了磁天线和电天线对周期修正项的影响,计算了实际传播介质中周期修正项的大小。结果表明:当传播路径上的电参数恒定时,周期修正项与传播距离有关,传播距离越大,感应电动势的周期修正项也越大,并且两者呈线性关系。同时,周期修正项也受等效电导率等因素的影响,在恒定的距离上,等效电导率越小,周期修正项反而越大。授时用户可以利用感应电动势周期修正项的数值计算结果修正传播路径上的时延,有效地提高传播路径时延计算的精度,从而提高授时精度。

Effect of Periodic Correction Term of Long Wave on Timing Accuracy

The periodic correction term is a characteristic quantity of long wave timing signal.It is often associated with signal trace point.In timing service,the periodic correction term is an important factor of the influence on long wave propagation delay.We discussed the difference of periodic correction term between the induced electromotive force at acceptance point and current signal at emission point.The influence of a magnetic antenna and an electric antenna is presented.The value of periodic correction term in real material is calculated in numeric method.The results show that the period correction term is related to the propagation distance,and the larger the propagation distance,the larger the period correction term.Meanwhile,periodic correction items are also affected by factors such as equivalent conductivity,and the smaller the equivalent conductivity,the larger the periodic correction is.Through the analysis of periodic correction items,the precision of propagation path delay calculation can be improved effectively and the timing precision can be improved.