摘要
针对多通道调制解调器(Modem)不同接收通道间时延值差异对双向卫星时间频率传递(TWSTFT)结果产生较大影响的问题,该文通过使用卫星模拟转发器的方法,实时测量地面站设备时延。采用多台站间两两双向的方法,归算后验证设备时延对三站闭合差结果的影响。依托国家授时中心的卫星双向比对网,开展了各地面站间基于中星12号卫星的TWSTFT试验。结果表明,通道时延对闭合差结果影响较大,在通道时延扣除前,误差可达数十纳秒;而在扣除后,结果优于0.2ns。这表明:多通道Modem各通道时延值不同引起的误差可有效测量并扣除,从而多台站开展TWSTFT是可行的。这样不仅提高了TWSTFT的执行效率,方便快捷地检验地面站间时间同步的准确度,而且节约了卫星资源的占用率。
Aiming at the problem that individual receiving channels of a multi-channel Modem may have different time delay values,which could impact the accuracy of two-way satellite time and frequency transfer(TWSTFT)results,the real-time delay due to ground station equipment by simulation of a satellite transponder was measured,and the effect of device delay on the triangle closure through bidirectional comparisons among three stations also was assessed in this paper.Then the actual TWSTFT tests at three ground stations were carried out using the CHINASAT 12of the TWSTFT network of the National Time Service Center as the signal relay.The experimental results showed that the delay of the ground station equipment had an obvious effect on the triangle closure,and the error was as high as tens of nanoseconds without deducting the channel delay,however,with deduction for the channel delay,the error was less than 0.2ns.This showed that the error caused by the difference in delay values of individual channels in multi-channel Modem could be effectively measured and subtracted,so it was feasible to carry out TWSTFT at multi-station,using a multi-channel Modem.This not only improves the efficiency of TWSTFT implementation,it can conveniently and quickly check the accuracy of time synchronization at ground stations,but also improves the use of satellite resources to some extent.
作者
王伟
李伟超
杨旭海
曹芬
陈亮
WANG Wei;LI Weichao;YANG Xuhai;CAO Fen;CHEN Liang(National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;Key Laboratory ofPrecision Positioning and Timing Technology,Chinese Academy of Sciences,Xi’an 710600,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《测绘科学》
CSCD
北大核心
2019年第8期6-12,共7页
Science of Surveying and Mapping
基金
国家自然科学基金项目(41604026)
