.vf / Elf Electromagnetic Waves In The Ionosphere In The Propagation Mechanism Studies

Due to the existence of magnetic field of the earth, the ionosphere behaves as a remarkably anisotropic media for LF and even-lower-frequency electromagnetic waves. It affects electromagnetic wave that propagates in it according to the frequency of the wave, greater effect for lower frequency; so for VF/ELF waves, the ionosphere is rather important. Usually it is electrons that work in the ionosphere plasma, while it has been widely proved that ions become quite noticeable at VF/ELF, but there is seldom any further research that was reported.Electron density and some other parameters of the ionosphere vary with space (altitude, longitude and latitude) and time (day and night, seasons, solar activities and so on), which is rather complicated. And especially at VF/ELF, the parameters change a lot in the height of a wavelength, so in the thesis the ionosphere is considered as a horizontally stratified anisotropic media, which is divided into any n thin horizontal and homogeneous slabs. A method of propagation matrix and matrix analysis theory is used to deduce the reflection and transmission coefficients, and the refractive index, which are then calculated by a numerical technique. Computation and comparison are made in detail when taking account of electron collision frequency or ion density respectively. Based on the work above, we try to do some discussing about the phenomenon and mechanism of VF/ELF propagation in the ionosphere.