基于频漂校准的氢钟铯钟联合守时研究

Study on joint time-keeping of hydrogen masers and cesium clocks based on frequency drift calibration

在没有外部溯源链路,利用氢钟铯钟联合守时的情况下,针对注重短期稳定度的场合,加权平均算法分配铯钟权重较小,不能充分发挥铯钟长期稳定度的问题,论文提出一种两级卡尔曼滤波算法生成本地原子时:第一级卡尔曼滤波利用铯钟长期稳定度好的特性,计算氢钟的频漂并且对氢钟频漂校准,第二级基于频漂校准后的氢钟和铯钟数据采用单状态变量的卡尔曼滤波算法生成本地原子时.实验结果表明,算法生成的原子时在保持短期稳定度的前提下,长期稳定度得到一定提升:十天稳的提升在10-15量级,月稳的提升在10-14量级.说明论文所提出的算法生成的本地原子时长期稳定度更好.

In the case of hydrogen masers and cesium clocks joint time-keeping without an external tracing link,to solve the problem that the weighted average algorithm can’t give full play to the long-term stability of the cesium clocks due to the small weight assigned to the cesium clocks by the occasions that focus on short-term stability,a two-stage Kalman filter algorithm to generate local atomic timescale is proposed in this paper.The first-stage Kalman filter uses the cesium clock to calculate the frequency drift of the hydrogen masers and calibrates the frequency drift of the hydrogen masers.The second-stage Kalman filter uses a single-state variable model to generate the local atomic time which is based on the data of cesium clocks and hydrogen masers whose drift has been calibrated.The experimental results show that the long-term stability of the local atomic timescale can be improved on the premise of maintaining short-term stability:the improvement of 10-day-stability is in 10^-15 and the improvement of month-stability is in 10^-14.It is shown that the long-term stability of the local atomic timescale generated by the proposed algorithm is better.