UTC（NTSC）远程复现方法研究与工程实现

发布时间：2018-01-28 22:19

本文关键词： UTC 卫星共视连续比对实时时间复现　出处：《中国科学院研究生院(国家授时中心)》2016年博士论文　论文类型：学位论文

【摘要】：国家授时中心承担着我国标准时间的产生、保持和发播任务。近年来,建立了与UTC同步的国家标准时间UTC(NTSC),2013年以来,保持与UTC偏差小于10ns。研究实用技术,采用多样化手段将高性能的国家标准时间提供给各行业用户,服务我国国民经济发展是国家授时中心的核心任务之一。本文提出的UTC(NTSC)远程复现方法,弥补了目前授时体系中对1~5ns实时授时手段的缺失,并提供了一种2ns精度的实时授时方案。本文在研究现有的远程时间比对方法基础上,提出了一种适应UTC(NTSC)远程复现的比对方法,解决了标准卫星共视方法测量存在间断,且不能实时输出比对结果的问题,研究了改进比对精度的方法,并在工程上实现了UTC(NTSC)远程复现系统,实现的用户本地复现时间与UTC(NTSC)偏差小于5ns。本文的主要研究内容如下:(1)深入分析国家标准时间远程复现的需求充分分析了目前授时手段的研究现状,调研各行业对高精度时频信号、时间溯源等方面的需求,结合我国标准时间产生和保持水平现状,对国家标准时间远程复现进行了深入分析,包括功能、性能和成本等。(2)研究了现有的远程时间比对技术通过对卫星共视、PPP时间传递、卫星全视法、卫星双向、光纤时间传递等时间比对技术的研究分析,发现现有的方法存在几方面问题,一是通用卫星共视法比对不连续,观测存在间隙;二是卫星共视法、PPP时间传递、卫星全视法等比对结果实时性较差,特别是PPP和全视法依赖事后精密轨道和钟差数据处理;三是卫星双向、光纤传递等方法链路专用,成本较高,难以大范围推广应用。(3)提出了UTC(NTSC)远程复现方法,并结合理论与试验研究提高复现精度基于卫星共视思想,提出了一种适宜UTC(NTSC)远程复现的远程时间比对方法,设计了灵活的观测周期,观测与数据处理并行,无观测间隙,保证持续不间断的溯源比对,解决了连续共视观测的数据处理、误差改正、不等精度数据融合等问题;设计了数据实时交换方法,解决了信息传递实时性要求带来的通信可靠性、环境适应性问题;研究并解决了多卫星导航系统共用带来的误差校准问题;研究了利用实时比对数据驾驭频率源,使其输出与UTC(NTSC)保持同步,并兼顾稳定度性能需求的控钟策略。(4)工程上实现了UTC(NTSC)远程复现系统的研制在对提出的UTC(NTSC)远程复现方法进行充分理论研究基础上,从工程应用角度,进一步对UTC(NTSC)远程复现系统的可靠性、稳定性、高度集成等要求进行分析,工程实现了UTC(NTSC)远程复现系统,建成了包括一个数据分析处理中心、若干台远程时间比对基准终端、若干台UTC(NTSC)远程复现终端、一台时延校准终端和一套远程数据传输网络的系统。(5)对系统的性能进行了充分测试开展了多项针对性测试试验,包括检验系统测试不确定度的零基线、短基线和长基线试验。各种基线长度测试均优于2ns的不确定度;将使用不同类型原子钟的复现终端安装在用户所在地,用卫星双向移动校准站作为独立测试手段,检验其复现UTC(NTSC)的性能,实测结果显示,使用铯原子钟的复现终端,其复现频率信号的天稳定度为1.8e-14,频率准确度为1.99e-14;使用铷原子钟的复现终端,复现频率信号的天稳定度为9.45e-14,频率准确度为1.36e-13。为研究并实现UTC(NTSC)复现系统,本文的创新工作如下:(1)提出了一种远程复现国家标准时间的方法以国家标准时间为参考,通过远程时间比对、钟驾驭等手段,直接向全国甚至世界范围内各地用户提供统一的标准时间信号,并依托现有的国际比对链路,实现复现信号向国际标准时间UTC的溯源。为用户提供了一种精度2ns,远优于卫星授时,成本与其相当,用户数量不受限制的授时新方案。(2)提出了一种新的实时、连续的共视比对方法标准卫星共视法一个观测周期为16分钟,其中13分钟有观测数据,存在3分钟观测间隙,共视数据事后交换处理,因此比对结果生成严重滞后,不适宜用于要求实时性的国家标准时间复现需求。本文提出了一种新的实时共视比对方法,打破了固有观测周期思路,设计了观测周期灵活设置的结构,解决了标准共视法周期存在间断,及数据事后交换处理的问题。(3)使用多种融合方法,增强时间复现可用性研究了不同导航系统之间系统偏差分布特点和规律,给出了时延偏差改正方法,解决了多导航系统共用引入的系统间偏差问题,且可视卫星的增加,大大增加了远程比对的基线长度,实现了多卫星导航系统之间的有效融合。分析了伪距和载波相位两种数据的特征,给出了一种适用的载波相位平滑伪距方法,实现了两种数据的融合共用,满足用户不等精度的需求。本文的研究成果目前已经应用到了北京、天津、陕西等地,为各地复现UTC(NTSC)信号,发挥实际价值。
[Abstract]:National time service center responsible for our standard time, maintaining and dissemination tasks. In recent years, the establishment of a national standard time synchronization with UTC UTC (NTSC), since 2013, with the UTC deviation less than 10ns. of practical technology, the use of diversified means to the national standard time high performance available to users in various industries service, the development of China's national economy is one of the core tasks of the national time service center. In this paper, the UTC (NTSC) remote replication method, made up of 1~5ns real-time timing means the current lack of timing system, and provides a scheme of 2ns real-time timing accuracy. Based on the method of remote time comparison on existing, this paper presents a new UTC (NTSC) on reproduction method of remote, provides a standard satellite common view method to measure the discontinuity, and can not be real-time output than the results of the research problem, improve the alignment precision The method and implementation of UTC in Engineering (NTSC) remote replication system, realize the user local recurrence period UTC (NTSC) and the main research contents of this paper are as follows: the deviation is less than 5ns. (1) analysis requirements of national standard time remote reproduction of the full analysis of the research status of measurement means at present, research of various industries for the high precision time and frequency, time traceability and other needs, combined with China's national standard time to generate and maintain the status quo of the national standard time remote replication is analyzed, including the function, performance and cost. (2) studied the remote time comparison of existing techniques based on satellite common view time transfer, PPP all in view, satellite, two-way satellite time transfer, analysis and research of optical fiber time comparison technology, found that the present method has several aspects, one is the general satellite common view than the continuous observation, there is a gap is two; The method of satellite common view time transfer, PPP, satellite as geometric results of poor real-time, especially PPP and all in view dependent precise orbit and clock data processing; three is a two-way satellite, special optical fiber transmission link method, high cost, difficult to promote a wide range of applications. (3) proposed UTC (NTSC) remote replication method, and combining the theory and experimental research to improve the accuracy of satellite common view based on the idea of reproduction, is proposed for UTC (NTSC) remote time comparison method of remote replication, the design of flexible observation cycle, observation and data processing in parallel, no observation gap, ensure traceability ratio continued uninterrupted to solve the common view, continuous observation data processing, error correction, data fusion problem of unequal precision; the design of real-time data exchange method, solves the real-time information transmission requirements bring communication reliability, environmental adaptability; research Study and solve the problem of error calibration of multi satellite navigation system sharing brings; using real-time data to control the output frequency of the source, and UTC (NTSC) in sync, and taking into account the stability of the performance requirements of the control strategy. The bell (4) project on the implementation of the UTC (NTSC) remote replication system in the proposed UTC (NTSC) study of the basic theory of remote full realization methods, from the point of view of engineering application, the UTC (NTSC) reliability, remote replication system stability, high integration requirement analysis, project implementation of UTC (NTSC) remote replication system, including the completion of the a data processing center some remote time comparison, the reference terminal, a plurality of UTC (NTSC) remote terminal system of a repetition, time delay calibration terminal and a set of remote data transmission network. (5) the system of the full test was carried out against a number of Test test, including test system test uncertainty of zero baseline and short baseline and long baseline tests. All test baseline length are better than 2ns uncertainty; reproduction terminal will use different types of atomic clocks installed on the user location, with two-way mobile satellite calibration station as an independent means of testing, test the repetition of UTC (NTSC) performance, experimental results show that the reproduction terminal using cesium atomic clock, the repetition frequency signal day stability is 1.8e-14, frequency accuracy is 1.99e-14; reproduction terminal using rubidium atomic clock, repetition frequency signal day stability is 9.45e-14, the frequency accuracy of 1.36e-13. for the research and implementation of UTC (NTSC) reconstruction system, the innovation of this paper are as follows: (1) proposed a remote country standard time to reproduce the national standard for reference, through remote time comparison, clock control means, directly to the full Even in the world around the user provides standard uniform time signal, and relying on the international comparison of the existing link, realize the reproduction signal to the international standard time source. UTC provides a precision 2ns for the user, is much better than that of GPS, the cost of its equivalent, a new timing scheme is not limited by the number of users (2.) put forward a new real-time, continuous satellite common view comparison method common view method an observation period of 16 minutes, with the observation data of 13 minutes, 3 minutes of observation space, common view data exchange processing, so the results generated serious lag, not suitable for the requirements of the national standard time of reproduction the demand of real-time. This paper presents a new real-time common view method, breaking the inherent observation period of ideas, design structure and flexible set of observation period, solve the standard CV cycle there is a gap, and After the data exchange processing. (3) the use of several fusion methods, enhance the availability of repetition time between different navigation system deviation distribution characteristics and rules, gives the correct method to solve the problem of delay deviation, deviation of system navigation system common introduced, and the increase of visible satellites, greatly increasing the length of distance compared to the baseline, to achieve the effective integration between multi satellite navigation system. Analysis of the characteristics of pseudorange and carrier phase two data, given a suitable carrier phase smoothing pseudo range method, realize the integration of two kinds of data sharing, to meet user needs unequal precision. The result of this research has been applied to Beijing, Tianjin, Shaanxi and other places, around the repetition of UTC (NTSC) signal, play the actual value.

【学位授予单位】：中国科学院研究生院(国家授时中心)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P127.1

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