基于VLBI站接收的火星探测器信号研究行星际闪烁

发布时间：2018-05-27 14:35

本文选题：行星际闪烁 + 太阳风　；参考：《中国科学:技术科学》2017年04期

【摘要】：利用VLBI单站对欧洲火星快车探测器(MEX)的太阳掩星过程进行观测,记录了太阳偏距(太阳中心到信号传播路径的垂直距离)在11 R⊙~160 R⊙范围内的MEX发射的X波段主载波信号,并通过VLBI宽带记录终端,提取了太阳风湍动导致的相位闪烁信息及相位闪烁功率谱,通过谱分析,测量了太阳风空间折射谱指数、折射结构常数与相位闪烁指数,探讨了利用相位闪烁指数反演沿视线方向的总电子含量(TEC)的可行性,分析表明,近太阳区域的相位闪烁显著强于远太阳区域;在3 mHz~0.3 Hz范围内,相位闪烁功率谱呈幂律分布,太阳风空间折射谱指数为-3.3±0.25,与Kolmogorov理论一致,且谱指数与太阳偏距无相关;表明在11 R⊙~160R⊙范围内,Kolmogorov理论可用于解释太阳风湍动及结构,太阳风折射结构常数与R近似满足~R~(-1.98±0.27)的关系,表明近太阳区域湍动强于远太阳区,利用相位闪烁指数获得的TEC与太阳活跃与平静期间模型计算值的变化趋势一致,试验表明,基于VLBI测站的多普勒测量及行星际闪烁研究可用于我国未来火星探测器的太阳掩星观测.
[Abstract]:The solar occultation process of European Mars Express (MEX) is observed by using VLBI single station. The X band main carrier signal of MEX is recorded in the range of 11R ~ (-) ~ (160R) from the solar deviation (the vertical distance from the solar center to the signal propagation path). The phase scintillation information and phase scintillation power spectrum caused by solar wind turbulence were extracted by VLBI wideband recording terminal. Through spectral analysis, the solar wind spatial refraction spectrum index, refraction structure constant and phase scintillation index were measured. The feasibility of using phase scintillation index to retrieve the total electron content along the line of sight is discussed. The analysis shows that the phase scintillation near the solar region is significantly stronger than that in the far solar region, and the power spectrum of phase scintillation is power law distribution in the range of 3 mHz~0.3 Hz. The spectral index of solar wind spatial refraction is -3.3 卤0.25, which is consistent with the Kolmogorov theory, and there is no correlation between the spectral index and the distance between the sun and the wind. It shows that the Kolmogorov theory can be used to explain the turbulence and structure of the solar wind in the range of 11R ~-(160R). The relation between the solar wind refraction structure constant and R approximately satisfies the R ~ (-1.98 卤0.27), which indicates that the turbulence in the near solar region is stronger than that in the far solar region. The TEC obtained by using the phase scintillation index is consistent with the calculated values of the solar active and quiet periods. The experimental results show that, Doppler measurements based on VLBI station and interplanetary scintillation can be used to observe the solar occultation of future Mars rovers in China.
【作者单位】：中国科学院上海天文台;中国科学院射电天文重点实验室;上海市空间导航与定位技术重点实验室;
【基金】：国家自然科学基金(批准号:11373061,11573057) 上海市空间导航与定位技术重点实验室资金(编号:06DZ22101) 上海市优秀学术/技术带头人计划(编号:14XD1404300) 上海市青年自然科学基金(批准号:Y457171001) 中国科学院关键技术人才项目和探月工程资助项目
【分类号】：P185.3;P228.6

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