氢原子钟的钟差预报方法研究

Study on the clock difference prediction method of hydrogen maser

卫星钟差预报精度直接影响导航系统的性能,由于氢钟具有良好的短期稳定性和低噪声特性,所以星载原子钟的物理特性可以借鉴氢原子钟钟差序列建立的预报模型进行研究。基于NTSC的氢钟资源,分别采用Kalman滤波模型、ARMA模型和二次多项式模型对原子钟钟差进行预测,并应用实测数据进行了验证,给出了不同预报模型在2~7 d的预报精度。研究结果表明,应用Kalman滤波模型预报的钟差,在所有预报时段上较ARMA模型和二次多项式模型均能获得更好的预测精度。

Satellite clock difference prediction plays an important role in satellite navigation and positioning, and the prediction precision has a significant impact on the capacity of navigation system. Since the hydrogen maser have good short-term stability and low noise characteristics, the physical characteristics of t he space atomic clock can take example by the prediction model established by the hydrogen maser difference sequence. In this paper, Kalman filter, ARMA and quadratic polynomial are introduced for forecasting the atomic clock difference based on the measured results of the hy drogen masers at NTSC, the results have been validated by actual measuring data in NTSC, and the prediction precisions of different models in 2~7 days are given. The results show that the prediction precision of the Kalman filter model is better than that of the ARMA model and quadratic polynomial model in all forecast periods.