基于CNN-LSTM-Attention的北斗卫星钟差预报

Satellite clock bias prediction for BDS based on CNN-LSTM-Attention

  • 摘要: 卫星钟差(satellite clock bias,SCB)是影响北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)性能的重要因素之一. 然而,现有的事后精密SCB产品无法满足高精度的实时定位、导航与授时(position, navigation and timing,PNT)服务的需求. 因此,为了进一步提高BDS应用的精密性和实时性,提出一种融合卷积神经网络(convolutional neural network,CNN)、长短期记忆网络(long short-time memory,LSTM)和注意力(Attention)机制的组合SCB预报模型. 所提模型首先利用CNN从时间片段中提取深层的时间特征,再由LSTM模型建立更长时间的依赖关系,然后引入注意力机制对LSTM的隐藏层进行自适应加权,平衡全局特征和局部特征捕捉,最终实现SCB的高精度实时预报. 最后,将本文所提出的模型与自回归综合移动平均(auto-regressive integrated moving average,ARIMA)模型、灰色模型(grey model,GM)、CNN模型以及LSTM模型进行了全方面的预报性能比较. 结果表明,在24 h的预报任务中,相对于ARIMA、GM、CNN以及LSTM模型,本文所提模型的预测精度分别提高了73.0%、76.6%、88.5%和74.8%.

     

    Abstract: Satellite clock bias constitute one of the key factors affecting the performance of the BeiDou Navigation Satellite System (BDS). However, existing post-processing precise satellite clock bias products fail to meet the demands of high-precision real-time positioning, navigation and timing (PNT) services. Therefore, to further enhance the precision and real-time capability of BDS applications, a combined satellite clock offbias prediction model integrating convolutional neural networks (CNN), long short-term memory (LSTM) networks, and Attention mechanisms is proposed. The proposed model first employs CNN to extract deep temporal features from time segments, then utilizes the LSTM model to establish longer-term dependencies. Subsequently, the Attention mechanism is introduced to adaptively weight the hidden layers of the LSTM, balancing the capture of global and local features. This ultimately achieves high-precision real-time forecasting of satellite clock offsets. Finally, the proposed model undergoes comprehensive forecasting performance comparisons against auto-regressive integrated moving average (ARIMA), grey model (GM), CNN, and LSTM models. Results demonstrate that for 24 h forecasting tasks, the proposed model achieves prediction accuracy improvements of 73.0%, 76.6%, 88.5%, and 74.8% respectively over ARIMA, GM, CNN, and LSTM models.

     

/

返回文章
返回