Study On Some Problems Related To Wave Propagation In The Troposphere And Ionosphere

Based on the theory of wave propagation in random media, the feasibility of controlling the tropospheric communication by acoustic wave and ionospheric effects on radio propagation has been investigated in this dissertation. Combined the theory of wave propagation in turbulent atmosphere with the principle of acoustic wave, the characteristic of controlling the tropospheric communication by acoustic wave is discussed. On the basis of the researching works about the fluctuation of the tropospheric refractive index with/without the disturbance of the acoustic wave, the relationship between the sound pressure, the sound pressure level and the sound wave power is calculated and discussed, the received fields and the received power for different incident wave frequency and different transmission distance are calculated with the acoustic wave disturbance, numerical results show that the frequency of acoustic wave has strong effect on the received fields and the received power. In addition, the calculation and comparison of the received power for different incident wave frequency and transmission distance are presented with/without the disturbance of the acoustic wave,which is significant to the use of controlling the tropospheric communication by acoustic wave disturbance. Meanwhile, according to the solution to the fourth-order moment equations under the conditions of the intensity fluctuations, the scintillation index in the ionosphere is studied, and the ionosphere plasma parameters in Zhongshan Station Area of Antarctica sky are obtained with the international reference ionosphere IRI2001 model. The mean arrival time, the pulse broadening changing with the characteristic parameters of the ionospheric irregularities are discussed in detail.