节点文献
卫星导航系统中的高精度时间同步误差分析与仿真
The Error Analysis and Simulation of High Accuracy Time Synchronization in Satellite Navigation System
【作者】 韩华；
【导师】 侯峙云；
【作者基本信息】 燕山大学 ， 光学工程， 2012， 硕士
【摘要】 随着全球卫星导航定位系统的发展，目前全球范围已建立了多个卫星导航系统。我国的COMPASS系统起步较晚，与国外其它导航系统相比有一定的差距。时间同步技术作为导航系统的基础、重要技术需要引起格外的重视。本文以双向时间频率同步为基础，以进一步提高时间同步精度为目标，针对TWSTFT的基本计算模型，时间同步信号在传输路径上的误差时延，以及时间同步信号调制方式等进行了研究。首先，对GPS系统，GLONASS系统，GALILEO系统以及COMPASS系统进行了简要介绍，并介绍了常用的时间同步方法，得出TWSTFT满足高精度的需求。其次，建立了TWSTFT的计算模型，并以此计算模型为出发点，仿真了模型中影响时间同步精度的电离层时延，对流层时延以及Sagnac效应误差等，得到用于高精度时间同步的误差修正模型，并对使用地球中轨卫星及小倾角轨道卫星进行时间同步时计算Sagnac效应误差的可行性进行了分析。然后，由于设备时延是计算模型中的一个较大误差项，所以本文对于传统地面站收发设备时延的测量进行了改进，并进行了实验验证。最后，TWSTFT是通过接收机测量经卫星转发的两待测地面站的伪距实现的，所以本文从码跟踪精度的角度出发分析仿真了不同调制方式对码跟踪精度的影响，得到了一种码跟踪精度高的调制方式。
【Abstract】 With the development of Global Navigation Satellite System, a number of satellitenavigation systems have been established. Comparing with the foreign navigation system,COMPASS System startes late and has a large gap between foreign navigation system.Time Synchronization Technology is the basic and important technology of the navigationsystem，it should be paid more attention. In order to improve the precision of timesynchronization. This paper studies the basic model of the Two-way Time and FrequencyTransfer(TWSTFT), the error of time synchronization signal in transmitting path and timesynchronization signal modulation mode.Firstly, This article introduces the GPS system, GLONASS system, GALILEOsystem and COMPASS system. It also introduces common methods of timesynchronization,then come to a conclusion that the TWSTFT meets the needs of highprecision demand.Secondly, This article set up a TWSTFT calculation model, and simulate theionosphere delay, troposphere delay and the Sagnac effect error. Finally got the errorcorrection model for the high precision time synchronization.Then analyse the feasibilityof using the MEO and the IGSO to calculate the Sagnac effect.Thirdly, As the equipment time delay is a considerable error in the calculation model.In this article, the traditional method of time delay measurement of ground stationtransceiver is improved and experimental verified.Finally, Two-way time synchronization is realizated by the measurements of pseudo-range which is transmitted by satellite transponder.This article analyses and simulates thedifferent modulation method for improving code tracking accuracy, and gets a highprecision modulation mode.
【Key words】 Two-way Time and Frequency Transfer； ionosphere delay； the Sagnac effect； equipment delay； code tracking accuracy；