摘要
在外部定位系统(如GPS、Loran-C等)受限的条件下,平流层伪卫星定位系统可以为用户提供定位和授时信息,其中时间同步技术是制约系统授时及定位精度的关键因素之一。为了提高伪卫星时间同步的精度,引入了非等应答对称双边双向时间同步技术(SDS-TWR-URT),解决了常用的微波双向时间同步技术(TWR)中因忽略应答时间差异导致的同步精度低的问题。仿真结果表明与常用的TWR技术相比,SDS-TWR-URT算法同步精度提高了45%。最后给出了提高时间同步精度的一些建议。
Pseudolites positioning system （PPS） in the stratosphere can provide the information of navigation and time to users in times of exterior positioning system （like GPS, Loran-C, etc. ） outages or in these systems denied areas. In PPS one of the key issues is time synchronization technology which confines the precision of timing and positioning. The algorithm of symmetric double sides two-way ranging with unequal reply time （SDS-TWR-URT） is introduced based on analyzing and comparing the different time synchronization methods for PPS. The proposed SDS-TWR-URT resolves the problem of the low synchronization precision caused by ignoring the unequal reply time in conventional microwave two-way ranging （TWR） technology. Simulation result demonstrates that com- pared to TWR, the synchronization precision is increased 45% around by the SDS-TWR-URT algorithm. Finally, some valuable suggestions to improve the synchronization precision of PPS are briefly summarized.
出处
《测控技术》
CSCD
北大核心
2009年第6期43-46,共4页
Measurement & Control Technology
基金
海军大连舰艇学院科技创新项目资助
海军大连舰艇学院科研发展基金项目(K200821)
关键词
伪卫星
时间同步
微波双向时间同步
非等应答对称双边双向时间同步
pseudolites
time synchronization
microwave two-way ranging
symmetric double sides two-way ranging with unequal reply time
