A New Ionosphere Sporadic E Research Method Based on Wavelet Decomposition and Reconstruction
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摘要: 电离层不规则体对卫星导航、通信、雷达系统等有重要影响。通过数值模拟及与实测数据的对比,论证基于小波分解与重构方法实现利用掩星数据反演电离层不规则体的可行性。以电离层偶发E层为例,利用国际参考电离层(IRI)模拟背景电离层电子密度分布,利用掩星探测的水平电子密度总含量δht反演不规则体信息,并与模拟数据进行比较。对2009年7月1-8日的COSMIC掩星数据进行小波分解与重构,将结果与SPIDR提供的地面观测数据进行对比。数值模拟及与实测数据的对比结果均表明,该方法能够较为准确地得到电离层不规则体的高度和强度信息,这对于电离层不规则体研究具有重要意义。Abstract: The ionospheric irregularities have important impact on the satellite navigation, communication, radar system etc. In this paper, the numerical simulation and observation data contrast are both carried out to validate the feasibility of wavelet decomposition and reconstruction method. Taking sporadic E for example, in numerical simulation, the background of the electron density distribution is simulated by the International Reference Ionosphere (IRI). Then the horizontal total electron density (δht) is used in the inversion of the ionosphere irregularities, and the results are compared with the simulated data. With the wavelet decomposition and reconstruction method of observation data, the COSMIC occultation data from 1 to 9 in July 2009 have been compared with the ground-based observation data provided by SPIDR. Both results show well accordance with the true value or observation which indicates the method is feasible for the inversion of ionosphere irregularities. This is in great significance for the research of ionosphere irregularities.
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表 1 匹配掩星事件小波分解结果与观测结果对比
Table 1. Comparison between wavelet reconstruction result of matching occultation and observation
测站代号 测站坐标 时间(UT) 临频
/MHz临频高度/km 高频分量
最大值/TECU高频分量最大值
对应高度/kmFF051 (51.7oN, 1.5oW) 2009年7月4日 18:00 4.1 103 3.38 100 FF051 (51.7oN, 1.5oW) 2009年7月6 日 06:00 3.13 107 1.10 102 AT138 (38oN, 23.5oE) 2009年7月2日 02:00 2.25 97 0.186 80.6 EA036 (37.1oN, 6.7oW) 2009年7月7日 03:00 2.21 115 0.13 98 JG055 (54.6oN, 3.4oE) 2009年7月5日 06:00 3.55 112 1.02 109 -
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