地下SLF/ELF水平电偶极子在球形地-电离层中产生的场  

Electromagnetic fields in spherical earth-ionosphere excited by SLF/ELF underground horizontal electric dipole

作　　者：王元新[1,2] 潘威炎[2] 金荣洪[1] 张红旗[2] 

机构地区：[1]上海交通大学电子工程系,上海200240 [2]中国电波传播研究所青岛分所,山东青岛266071

出　　处：《电波科学学报》2009年第6期1002-1008,共7页Chinese Journal of Radio Science

基　　金：国家科技支撑计划"基于空间对地观测的地震监测技术预测方法与应用示范"(项目编号:2008BAC35B05)

摘　　要：在非理想导电地面与电离层条件下,导出了地下SLF/ELF水平电偶极子在地上、地下及电离层中产生的电磁场的球谐级数表达式。并提出了一种加速收敛算法,算出了大气层及电离层中的电磁场分布。计算结果表明:地下几十公里的水平电偶极子产生的场除了增加了一个固定衰减外,与地面上的水平电偶极子产生的场分布完全相似,它产生的电磁场可理解为电波首先垂直地透过土壤,然后在地-电离层腔体中传播。在SLF频段,地-电离层空腔中的电磁场可理解为两个"行波"的叠加。在ELF频段,空腔中的电磁场是驻波,其频率变化规律能正确反映出"舒曼"谐振现象。The spherical harmonic series expressions of electromagnetic fields excited by SLF/ELF underground horizontal electric dipole on the ground, under the ground and in ionosphere have been derived when earth and ionosphere are regarded as the non-ideal electric conductor. Analgorithm of improving the speed of convergence is presented. The electromagnetic fields in the air and ionosphere have been calculated by this algorithm. The results indicate that the fields excited by the underground horizontal electric dipole below several dozens of kilometers are completely similar to those excited by the horizontal electric dipole above the ground besides a fixed attenuation. Therefore, the electromagnetic fields excited by it may be understood that the electric wave first vertically penetrates the soil, and then prop agates in earth-ionosphere cavity. The electromagnetic fields in earth-ionosphere cavity are the sum of two travelling wave in SLF band. The electromagnetic fields in the cavity are a kind of standing wave in ELF band. The variation of the amplitude verse frequency coincides with the Schumann resonance.

关 键 词：水平电偶极子 地-电离层空腔 球谐级数 “舒曼”谐振 

分 类 号：TN011[电子电信—物理电子学]