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Numerical Prediction Methods for Clock Deviation Based on Two-Way Satellite Time and Frequency Transfer Data 被引量:3
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作者 GUO Hairong YANG Yuanxi HE Haibo 《Geo-Spatial Information Science》 2008年第2期143-147,共5页
Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and freq... Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant influence of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the clock deviation sequence, the predicted values of polynomial model are implausible. The prediction precision of spectral analysis model is very low, but the principal periods can be determined. The prediction RMS of 6-hour extrapolation interval is Ins or so, when modified AR model is used. 展开更多
关键词 time prediction time transfer two-way satellite time and frequency transfer
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Technology of shipboard two-way microwave time synchronization
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作者 付永杰 李东光 刘旭东 《Journal of Beijing Institute of Technology》 EI CAS 2014年第4期511-518,共8页
For the high precision time synchronization demand of ships, advantages and disadvantages of the present time transfer methods are analyzed, the two-way microwave time transfer (TWMTT) method is adopted to resolve t... For the high precision time synchronization demand of ships, advantages and disadvantages of the present time transfer methods are analyzed, the two-way microwave time transfer (TWMTT) method is adopted to resolve the time synchronization problem in the Naval Ship Formation. After expounding the principle and system composition of TWMTT method, the various factors influencing the synchronous precision are analyzed, such as time-interval measurement error, TWMTT equipment delay error, signal propagation error in air, and signal delay error caused by shipping. To improve the time synchronization precision, all the error sources above are deduced with mathematical measures to definite the critical one, and the signal processing measures such as Pseudo code spread spectrum time comparison signal generation technology, FFT fast acquisition technology and precise tracking technology are used into the modem which is the core equipment of the TWMTT. And, calibration method of TWMTT equipment delay are developed. Through theoretical a- nalysis and simulation verification, the precision of shipboard two-way microwave time synchroniza- tion can reach 1 ns. 展开更多
关键词 two-way microwave time transfer(TWMTT) time synchronization time delay error analysis
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飞行自组织网的全双工双向时间传递技术研究
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作者 陈聪 徐强 +2 位作者 赵宏志 邵士海 唐友喜 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第7期2732-2739,共8页
针对飞行自组网(FANET)中节点间相对运动导致双向时间传递精度下降的问题,该文提出一种全双工双向时间传递(TWTT)方法。首先,根据全双工双向时间传递过程构造了需要求解的方程组,推导了单次时间传递的同步误差表达式;然后,分析了在无频... 针对飞行自组网(FANET)中节点间相对运动导致双向时间传递精度下降的问题,该文提出一种全双工双向时间传递(TWTT)方法。首先,根据全双工双向时间传递过程构造了需要求解的方程组,推导了单次时间传递的同步误差表达式;然后,分析了在无频偏和有频偏条件下,迭代进行全双工双向时间传递的收敛性;最后,通过仿真分析和实验验证比较了全双工双向时间传递方法和传统双向时间传递方法的性能。仿真和实验结果表明,全双工双向时间传递方法在节点高速机动下,时间同步精度可达到与物理层时间戳相同的精度,优于现有的运动补偿方法。 展开更多
关键词 飞行自组网 带内全双工 双向时间传递 非对称传播时延
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The method and experiment analysis of two-way common-view satellite time transfer for compass system 被引量:2
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作者 LIU Li TANG GuiFen +3 位作者 HAN ChunHao SHI Xin GUO Rui ZHU LingFeng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第8期95-101,共7页
Time synchronization between ground and satellites is a key technology for satellite navigation system. With dual-channel satellite, a method called Two-Way Common-View(TWCV) satellite time transfer for Compass system... Time synchronization between ground and satellites is a key technology for satellite navigation system. With dual-channel satellite, a method called Two-Way Common-View(TWCV) satellite time transfer for Compass system is proposed, which combines both characteristics of satellite common-view and two-way satellite-ground time transfer. By satellite-ground two-way pseudo-range differencing and two stations common-view differencing, this TWCV method can completely eliminate the influence of common errors, such as satellite clock offset, ephemeris errors, troposphere delay and station coordinates errors. At the same time, ionosphere delay related to signal frequency is also weakened significantly. So the precision of time transfer is improved much more greatly than before. In this paper, the basic principle is introduced in detail, the effect of major errors is analyzed and the practical calculation model in the Earth-fixed coordinate system for this new method is provided. Finally, experiment analysis is conducted with actual Compass observing data. The results show that the deviation and the stability of the satellite dual channel can be better than 0.1 ns, and the accuracy of the two-way common-view satellite time transfer can achieve 0.4 ns. All these results have verified the correctness of this TWCV method and model. In addition, we compare this TWCV satellite time transfer with the independent C-band TWSTFT(Two-Way Satellite Time and Frequency Transfer). It shows that the result of the TWCV satellite time transfer is in accordance with the C-band TWSTFT result, which further suggests that the TWCV method is a remote high precision time transfer technique. The research results in this paper are very important references for the development and application of Compass satellite navigation system. 展开更多
关键词 satellite navigation PSEUDO-RANGE time transfer clock offset two-way common-view (TWCV)
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应用双向时间传递的重力卫星时标误差自主测量
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作者 陈莉 王跃科 +1 位作者 杨俊 张传胜 《空间科学学报》 CAS CSCD 北大核心 2013年第3期302-307,共6页
星间时标误差的自主测量对于中国自主研发地球重力卫星具有重要意义.提出利用双向时间传递法实现重力卫星时标误差的自主测量,设计了测量方案,建立了包含卫星运动导致的链路非对称、电离层效应、设备零值以及随机测时误差在内的测量模型... 星间时标误差的自主测量对于中国自主研发地球重力卫星具有重要意义.提出利用双向时间传递法实现重力卫星时标误差的自主测量,设计了测量方案,建立了包含卫星运动导致的链路非对称、电离层效应、设备零值以及随机测时误差在内的测量模型.结合地球重力卫星相关特性,分析了时标误差测量中各误差源的影响及相应的误差校正方法.以GRACE重力卫星为例,利用提出的方法和校正措施,星间时标误差自主测量精度可以达到0.62 ns,其中误差主要来自系统零值标定误差和随机测时误差. 展开更多
关键词 时标误差 自主测量 双向时间传递 地球重力卫星
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BDS卫星精密钟差性能综合评定 被引量:5
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作者 王威 王宇谱 +1 位作者 王彬 赵华凯 《导航定位学报》 CSCD 2020年第1期20-25,37,共7页
为了进一步服务于北斗卫星导航系统(BDS)的精确导航、定位和授时,对BDS卫星的高精度钟差数据进行综合评定:分析星地双向时间比对(TWTT)及精密定轨与时间同步(ODTS)2种卫星钟差确定方法的特点与差异;然后从卫星钟差数据的连续性、内符合... 为了进一步服务于北斗卫星导航系统(BDS)的精确导航、定位和授时,对BDS卫星的高精度钟差数据进行综合评定:分析星地双向时间比对(TWTT)及精密定轨与时间同步(ODTS)2种卫星钟差确定方法的特点与差异;然后从卫星钟差数据的连续性、内符合精度、外符合精度以及计算得到的时域稳定度4个方面,对国际全球卫星导航系统服务组织(IGS)分析中心提供的BDS ODTS卫星钟差和TWTT卫星钟差的数据质量进行分析和讨论。分析认为,IGS不同分析中心的数据缺失率规律相似,但是德国地学研究中心(GFZ)的缺失率最高,欧洲定轨中心(CODE)的缺失率相对较低;TWTT精密卫星钟差的内符合精度最高,数据拟合精度即均方根(RMS)为0.37 ns,CODE、GFZ、武汉大学GNSS中心(WHU)钟差产品受到定轨误差等其他因素的影响,其拟合精度相对较低,RMS值分别为0.53、0.71、0.65 ns;4种精密星钟产品的天稳定度指标均到达1×10^-14量级,但TWTT结果所反映的噪声特性与3个分析中心的产品略有不同。 展开更多
关键词 北斗卫星导航系统 卫星钟差 精度评定 星地双向时间比对 精密定轨与时间同步
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Research on inter-satellite measurement technique in high dynamic environment
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作者 王永庆 孙立达 +2 位作者 杨丽云 姜洪伟 吴嗣亮 《Journal of Beijing Institute of Technology》 EI CAS 2015年第2期233-239,共7页
An improved measurement algorithm, based upon the theory of two-way time transfer ( TWTT), is proposed to measure satellites with high speeds. The algorithm makes theoretical analyses and corresponding deductions on... An improved measurement algorithm, based upon the theory of two-way time transfer ( TWTT), is proposed to measure satellites with high speeds. The algorithm makes theoretical analyses and corresponding deductions on a relative motion model of two satellites, and eliminates the measurement error caused by the equipment delay when a satellite moves at a high speed. Theoretical analysis and simulation results demonstrate that in comparison with the conventional TWTT algorithm, the proposed algorithm can significantly enhance the measurement accuracy of the inter-satellite ranging and time synchronization, and the algorithm is more effective with the relative velocity between the satellites and transmitting delay becoming larger. 展开更多
关键词 two-way time transfer RANGING time synchronization measurement accuracy
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