电离层干扰对GPS掩星弯曲角和温度精度的影响

The Effects of Ionospheric Disturbances on the Accuracy of GPS Radio Occultation Bending Angle and Temperature

  • 摘要: 以MSIS90大气模式和3D NeUoG电离层模式为背景大气,仿真模拟了电离层暴、电离层行扰和电离层槽对CPB掩星弯曲角电离层残差及温度精度的影响。结果表明,在太阳活动活跃期,弯曲角电离层残差在35-50 km高度范围内可达1.5μrad,其标准差可达0. 9μrad;在15-35 km高度范围内可达4μrad,其标准差可达1. 4μrad。电离层暴和电离层槽可使弯曲角电离层残差标准差增大20多倍;电离层行扰可使弯曲角电离层残差标准差增大数倍。电离层干扰引起的电离层残差可使15-35 km高度范围内温度反演误差高达8K,这样的温度误差会对掩星观测的日平均温度和月平均温度产生显著影响。因此,需要发展新的电离层修正方法;在掩星气候监测中,需加强电离层监测,并结合监测结果剔除电离层干扰误差。

     

    Abstract: Based on MSIS90 atmospheric and 3D NeUoG ionospheric models,three types of ionospheric disturbances, i. e. ionospheric storm,traveling ionospheric disturbance(TID)and ionospheric trough were simulated,and their effects on bending angle residual ionospheric errors(RIEs) and temperature accuracy were analyzed. The results show that under high solar activity level, the bending angle RIE and its standard deviation can reach 1. 5 prad and 0. 9 μrad, in the impact height range of 35一50 km; 4μrad and 1. 4 μrad, respectively, in the impact height range of 15一35 km. The ionopsheric storm and trough can enlarge the bending angle RIE standard deviations by more than 20 times, and TID can enlarge the bending angle RIE standard deviations by several times. Under the influence of ionospheric disturbances, temperature errors can reach 8 K and can pollute the UPS RO daily-mean and month-mean observations. Hence,itis desirable to develop ionospheric correction algorithms;the temperature outliers caused by ionospheric disturbances should be removed according to ionospheric monitoring results.

     

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