摘要
实时动态差分定位(Real-Time Kinematic,RTK)时间传递方法具有高可靠性、高灵活性以及不依赖外部产品的特点,近年来众多学者针对其在高精度授时领域中的应用展开了广泛研究。然而该方法实现高精度时间传递的前提是模糊度参数估计的高准确性,错误的初始模糊度会导致钟差解算严重偏离真值。针对该问题,本文提出了一种基于钟差约束的模糊度估计方法,来提升RTK授时服务性能。在历元内估计钟差时,排除发生周跳或者初次出现的异常卫星,获取准确的钟差估计结果,再通过单差模型,利用钟差对异常卫星的模糊进行约束,得到异常卫星的高精度模糊度初值,削弱后续计算中错误模糊度对钟差的影响。本文采用共钟实验以及短基线实验对该方法进行验证,结果表明:提出的方法可极大削弱模糊度偏差对钟差估计结果的影响,共钟实验中,相对于未改进的原始方法,解算得到的钟差序列峰峰值从0.510ns降低到0.137ns,标准差(Standard Deviation,STD)从0.120ns降低到0.014ns;短基线5组单天实验结果中,99%的秒脉冲(Pluse Per Second,PPS)鉴相结果都分布在1ns之内,PPS序列峰峰值最大为1.33ns,最小为1.11ns,标准差最大为0.19ns,最小为0.14ns,证明本文提出的方法,能有效提升RTK授时服务性能。
The Real-Time Kinematic(RTK)time transfer method,characterized by high reliability,flexibility,and independence from external products,has been widely studied by many scholars in recent years for its application in high-precision timekeeping.However,the prerequisite for achieving high-precision time transfer with this method is the high accuracy of ambiguity parameter estimation.Incorrect initial ambiguity can lead to significant deviations in clock difference solutions from the true values.To address this issue,this paper proposes an ambiguity estimation method based on clock difference constraints to enhance the performance of RTK timekeeping services.When estimating clock differences within an epoch,satellites with cycle slips or newly emerged anomalies are excluded to obtain accurate clock difference estimates.Then,through the single difference model,the ambiguity of the anomalous satellites is constrained by the clock differences to obtain high-precision initial values of the anomalous satellite ambiguities,thereby reducing the impact of incorrect ambiguities on subsequent clock difference calculations.This paper validates the proposed method through common clock experiments and short baseline experiments.The results show that the proposed method can significantly reduce the impact of ambiguity deviations on clock difference estimates.In the common clock experiment,compared with the original unimproved method,the peak-to-peak value of the calculated clock difference sequence decreased from 0.510 ns to 0.137 ns,and the standard deviation(STD)decreased from 0.120 ns to 0.014 ns.In the five groups of single-day short baseline experiments,99%of the Pulse Per Second(PPS)phase comparison results were within 1 ns,with the maximum peak-to-peak value of the PPS sequence being 1.33 ns and the minimum being 1.11 ns,and the maximum standard deviation being 0.19 ns and the minimum being 0.14 ns.This proves that the method proposed in this paper can effectively enhance the performance of RTK timekeeping services.
出处
《现代传输》
2025年第4期66-71,共6页
Modern Transmission
关键词
RTK
单差
模糊度
时间传递
RTK
Single Difference
Ambiguity
Time Transfer
