Radio Wave Propagation And Scattering Through The Ionospheric Sporadic E-layer And Heated F-layer Irregularities

With the development of science technology, people have come into an age of information. Undoubtedly communication occupies a pivotal position. Especially, the ionosphere shortwave communication is heavily favored in the military application with its advantages such as the flexibility, the stable signal, the ability of long communication distance, the simple device and the low cost. In recent years, the researches on the ionosphere irregularity relevant problems of heating ionosphere artificially, the sporadic E layer(Es layer) communication and the ionosphere scattering communication become more and more popular. The influence of ionosphere irregularity on the shortwave communication is obvious. So this paper also does some work about it on the base of the previous study.Firstly, according to the wind shear theory of ionosphere, the equations of the Es layer formation are listed. The electron density distribution model of Es layer is obtained after the equations solved by using the numerical chasing method. The main affecting factors of Es layer formation process are analyzed. Then also the 2-dimensional electron density and electron temperature distribution model of heated F layer are obtained after the heating equations solved by using the numerical explicit difference scheme method. And the effects of the related parameters of the heating electromagnetic wave on the heating result are analyzed.Then taking the 2-dimensional models of the Es layer and the heated F layer obtained last chapter as the background environment of radio wave propagation, using Runge-Kutta method to solve the ionosphere Ray-tracing equations, the propagation trajectory of the radio wave is obtained. Different propagation processes of short wave with different frequency and different launching elevation are analyzed. Having the model of the Es layer irregularity as the background of electromagnetic wave scattering, the multi-path effect and the Doppler effects in the irregularity scattering communication, are simulated by using the layered method. It tries to explain the relationship between the electron density of irregularity and the scattering communication results from a different perspective.Finally, the problem of the ionosphere short wave communication is discussed in the way of short wave channel system. The whole short wave propagation process is regarded as a whole time varying system which it subjects to some statistical laws by using the method which ignores the interaction between the electromagnetic wave and the ionosphere. After the input signal modulated by the typical probability distribution models which are abstracted from a large amount of short wave propagation experimental data, the output signal which accords with the statistical laws of received signal in the experiment is simulated.