强L波段太阳射电暴对GNSS性能和定位误差的影响

以2006年12月13日射电爆发事件为例, 利用国际GNSS服务(international GNSS service, IGS)观测台网数据, 结合L波段太阳射电流量和幅度闪烁指数监测数据, 研究了向阳面地基台站对这次射电暴的响应.重点分析了我国境内几个典型地区台站载噪比的变化特征, 并评估此次事件对不同地区GNSS服务和定位精度的影响程度.结果表明, 太阳射电暴期间:1)GNSS信号受到严重干扰, 几乎所有向阳面IGS台站都受到影响, 影响程度呈现出明显的随太阳入射角变化特征; 2)此次事件造成多个IGS台站锁定卫星数目小于4颗, 大面积连续性失锁、间歇性失锁和导航信号完全中断现象发生; 3)中国境内多个台站的定位误差显著增加, 伪距单点定位误差高达40~60 m, 精密单点定位(precise point positioning, PPP)误差达到2 m左右, 一些台站发生短时定位服务中断; 4)这次事件给日下点附近的台站造成非常严重的影响, PPP误差超过10 m, 而且还出现长达约10 min的定位服务中断.文中结果能为第三代北斗导航卫星系统在评估空间天气威胁方面提供借鉴和参考.

Impact of intense L-band solar radio burst on GNSS performance and positioning accuracy

The response of ground-based observation network to the solar radio burst (SRB) on 13 December 2006 is analyzed in details by jointly using the GNSS observation data from the IGS, the L-band solar radio flux data and amplitude scintillation index data. The focus is on the variation of the carrier-to-noise ratio in several typical areas in China during SRB. Furthermore, the impact of this event on CNSS performance and positioning accuracy is evaluated. The results showd that during this SRB: 1) GNSS signals were seriously interfered, and almost all of the IGS observation stations located on sunlit hemisphere were affected. The influence showed a significant dependence on solar incident angle. 2) This event resulted that the number of locked satellites was less than four in multiple IGS stations. Additionally, continuous loss of lock, intermittent loss of lock and complete disruption of the GNSS services occurred frequently. 3) For IGS stations in China, the positioning error was increasing so significantly that the pseudorange single-point positioning error was up to 40-60 m, the PPP error was about 2 m, and short-term positioning service outage occurred for some stations. 4) For areas near the sub-solar point, the positioning accuracy was seriously degraded. The PPP error was increasing to more than 10 m, and the positioning service outage lasted about 10 min. The results of this article can be used as a reference to evaluate space weather threat to Beidou 3 for engineers.