垂直电偶极子在地-电离层波导中场的球级数解

在非理想导电地面与电离层条件下,我们导出了ELF/SLF垂直电偶极子在球形地-电离层壳体中产生的电磁场的球谐级数表达式,采用一种加速收敛算法,算出了波导中的电磁场分布.根据计算结果,在SLF频段,地面与电离层之间的电磁场可理解为二个"行波"的叠加,且与SLF频段的球面二阶近似算法计算结果吻合很好.在ELF频段,壳体中的电磁场是驻波,其频率变化规律能正确反映出"舒曼"谐振现象.

Spherical harmonic series solution of fields excited by vertical electric dipole in Earth-ionosphere cavity

In this paper, the spherical harmonic series expressions of electromagnetic fields excited by ELF/SLF vertical electric dipole in spherical Earth-ionosphere guide taken earth and ionosphere as the imperfectly electric conductor are derived, and a method to speed numerical convergence is presented. The numertical results of electromagnetic fields in the cavity show that the electromagnetic fields between earth and ionosphere may be seen as the sum of two travelling waves, and it is good agreement with that of famous spherical second order approximation for SLF band. Moreover, the electromagnetic fields in the guide are a kind of standing waves, and the variation of the amplitude verse frequency coincides with the schumann resonance for ELF band.