电离层电子含量是影响卫星导航定位精度的重要因素.利用IGS分析中心提供的2006年和2007年中国境内5个IGS跟踪站的电离层电子含量数据,采用时间序列分析理论中的ARMA模型,对未来5d内的电子含量进行预报.结果表明,ARMA模型较为精确地模拟了1—5d的电离层网格电子含量数据.在24h预报时间内,5个跟踪站的ARMA模型预报值的绝对误差全部可控制在1TECU的精度范围内;在36h预报时间内,预报相对精度绝大部分可保持在90%以上;在5d预报时间内,电子含量预报相对精度大部分仍可达到90%以上;另外,93.3%的预报数据绝对误差小于2TECU.
The total electron content (TEC)of the ionosphere is an important factor influencing the accuracy of satellite navigation. TEC prediction for five days was carried out by means of the Autoregressive Moving Average (ARMA) model of time series theory on the basis of the TEC data from five International GPS Service (IGS) tracking stations in China in 2006 and 2007. The results show that ARMA model can accurately simulate the TEC data in ionospheric grids within five days. The absolute errors of ARMA model prediction at the five IGS stations for 24h prediction are less than 1.0TECU. The relative accuracy for 36h prediction mostly remains over 90%. For five-day prediction, the relative accuracy of TEC prediction obtained by our method can still reach above 90%. Moreover,the absolute errors for 93.3% of the prediction data are less than 2.0TECU.