›› 2013, Vol. 42 ›› Issue (3): 0-0.

• 学术论文 •    下一篇

卫星钟差预报的小波神经网络算法研究

王宇谱1,吕志平2,陈正生2,崔阳3   

  1. 1. 信息工程大学地理空间信息学院
    2. 信息工程大学测绘学院
    3. 解放军信息工程大学
  • 收稿日期:2012-10-08 修回日期:2013-01-20 出版日期:2013-06-20 发布日期:2014-01-23
  • 通讯作者: 王宇谱 E-mail:987834660@qq.com
  • 基金资助:
    国家自然科学基金面上项目

Research the Algorithm of Wavelet Neural Network to Predict Satellite Clock Bias

  • Received:2012-10-08 Revised:2013-01-20 Online:2013-06-20 Published:2014-01-23

摘要: 卫星导航系统中星载原子钟的钟差预报在优化导航电文中的钟差参数、满足实时动态精密单点定位的需求和提供卫星自主导航所需的先验信息方面具有重要的作用。 本文根据星载原子钟钟差的特点,提出了一种基于一次差方法的小波神经网络钟差预报算法:首先对钟差相邻历元间作一次差后的差值进行建模,根据时间序列预报一次差的值,然后再将预报的一次差还原,得到钟差预报值。该方法使得预报钟差的小波神经网络不但模型结构简单而且预报精度高。最后,通过算例将本文所建模型与常用的二次多项式模型和灰色模型进行对比,结果表明一次差方法可以使给定结构的小波神经网络的钟差预报精度得到显著提高,而且本文所建模型的预报效果优于两种常规模型;同时对各模型的预报结果进行分析,得到了一些有益的结论。

关键词: 卫星钟差, 预报, 一次差, 小波神经网络

Abstract: Satellite clock bias (SCB) prediction plays an important role in satellite navigation system, such as optimizing clock parameters in navigation message, meeting the needs of real-time dynamic precise point positioning and providing the required information for satellite autonomous navigation. It is proposed that a wavelet neural network (WNN) model based on a method of once difference to predict clock bias considering the characteristic of SCB in this paper. The main ideas are that firstly two SCB values of adjacent epoch are made once difference to obtain the corresponding once difference sequences, then modeling to predict the once difference values of following time series. At last, the predicted sequences are recovered to the corresponding predicted SCB. This method makes the WNN model of SCB prediction not only employs simple framework but also has high prediction precision. Through prediction examples, the paper compares the above model with two common models, i.e. Quadratic Polynomial (QP) model and GM(1,1) model; the results show that the method of once difference can evidently improve the prediction precision of SCB for the given WNN and that the proposed model possesses better performance compared with the common models in SCB prediction. At the same time, the prediction results of all models mentioned in the paper are analyzed, and some useful conclusions are educed.

Key words: satellite clock bias (SCB), prediction, once difference, wavelet neural network