摘要
在定位基准受限海域,为满足船只对飞行器精密定位的需求,提出了一种利用海面无线传感器网络协同对飞行器定位的技术。给出了协同定位的数学模型,引入双向不等时漂的时间同步方法(two-way timingwith unequal time drift,TWT-UTD),解决了因忽略时钟漂移导致的低同步精度问题。Monte Carlo仿真表明,通过优化定位精度因子,协同定位的精度优于常用的3坐标雷达跟踪精度;与无时漂往返校时技术相比,TWT-UTD同步精度提高了20%以上,将等效测距误差减小了3 m。
To satisfy the requirement of precise positioning and tracking for flying vehicle（FV） in times of exterior location datums（like GPS） outages or in these datums denied sea areas,a cooperative positioning technique（CPT） for the FV is proposed.First,the time of arrival（TOA）-based cooperative positioning algorithm（CPA） is presented after building station Cartesian coordinate system for cooperative positioning.Second,time synchronization among the nodes is crucial to guarantee CPT.Taking a single-hop S2WSN as an example, the problem of low synchronization precision, which is caused by ignoring unequal reply time in conventional round-trip timing （RTT） method in joint tactical information distribution system （JTIDS）, is resolved by two way timing with unequal reply time （TWT-UTD）. Finally, a conceptual numerical simulation system is designed to verify the effectiveness of the proposed methods by Monte Carlo simulation over 1 000 runs. The simulation results show that the absolute bias of the FV tracking by the proposed CPA is superior to that of the conventional single ship based relative positioning method through optimizing the position dilution of precision among the sea-surface nodes and the FV. Meanwhile, compared with the RTT method in JTIDS, the synchronization precision is increased by more than 20% via TWT-UTD method whilst the equivalent ranging error being reduced by 3 m.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2009年第12期1415-1418,1422,共5页
Geomatics and Information Science of Wuhan University
基金
国家自然科学基金资助项目(60532070)
关键词
海面无线传感器网络
协同定位
到达时间
时间同步
sea-surface wireless sensor networks
cooperative positioning
time of arrival（TOA）
time synchronization
