授时系统性能评估方法研究

Timing system is widely used in industry and defense fields, which has been put forward more and more requirements by the users. However, the performance evaluation criterion of timing system is not unified at present, the characterization forms of stability, accuracy, uncertainty, deviation etc bring certain difficulties in fusion of timing system. Although some countries and organizations have developed the relevant evaluation work, no clear expression shows how to characterize the timing indexes. The confusion of various technical parameters leads the published data in-comparability, even an approximate range is given by part evaluation results which brings users a lot of inconvenience..Based on BeiDou Timing Performance Evaluation System, we integrate the relevant technical indexes between satellite and foundation timing systems, with studying the timing performance evaluation method to establish the unified timing evaluation criterion and indexes characterization, which drives the compatibility and interoperability among timing systems. Meanwhile studying the distribution and transmission regulations of timing errors, we explore the complementary and fusion methods of satellite-foundation timing performance, thus will improve the users timing precision from ten nanoseconds order to 3~5ns by giving the publishing and using methods, which lays the foundation for the establishment of Chinese satellite-foundation fusion timing system.

授时系统在工业及国防领域有着广泛的应用，用户对授时性能提出了越来越多的要求。然而目前各授时系统对于性能的评价准则并不统一，稳定度、准确度、不确定度、偏差等各种表征方式给授时系统的融合带来了一定困难。虽然一些国家及组织开展了相关的评估工作，但均无明确表述授时指标该如何表征。各种技术参数较为混乱，公布的数据不具有可比性，甚至部分评估结果只给出了个大概范围，给用户的使用及体验带来了众多不便。.基于我们已经建成的北斗授时性能评估系统，整合星地、地基授时系统的相关技术指标，研究授时系统的性能评估方法，建立统一的授时性能评价准则和指标表征方式，带动授时系统之间的兼容与互操作。同时研究授时误差的分布及传递规律，探索星地授时性能互补与融合的方法，给出评估结果的发布与使用方法，将用户端授时精度由十纳秒量级提高至3ns以内，为我国星地一体化授时系统的建立奠定基础。

目前各授时系统对于性能的评价准则较为混乱，指标表征方法也不统一。本项目整合星基、地基授时系统的相关技术参数，提出了对授时系统广播UTC时间与实际UTC偏差进行测试的概念方法，统一了星地授时系统的性能表征体系。同时建立了全天侯连续监测的GNSS、BPL授时性能评估系统，评估系统的监测不确定度优于3ns。差分授时增强试验结果表明，外场站放置监测设备接收主站的评估结果，能够将卫星导航系统的授时精度由几十纳秒提高到纳秒级，对授时结果的改善比例至少在50%以上。该方法的提出填补了授时系统性能表征与使用的空白，为我国星地一体化授时系统的建设和应用提供支撑。