Propagacja fal radiowych w łączności satelitarnej. Radiowaves propagation in satellite communications systems

This monograph discusses the different effects contributing to the overall loss of signal propagation along Earth-space paths and suggests ways to improve the design of communication systems.
The work begins with a brief overview of the theoretical aspects of the use of the geostationary orbit for microwaves propagation.
The chapter two is concerned with the propagation of microwaves in the troposphere. The discussion includes signal attenuation due to precipitation, clouds, fog, and atmospheric gases, an increase in noise and total signal degradation due to precipitation, emission noise from absorbing media (radio noise increase), and signal depolarization by raindrops. This type of radiation covers a spectrum wider than the microwave spectrum.
Chapter three analyses atmospheric attenuation. In practice, statistical description is one of satisfactory way to present the results of modelling of satellite links in undesired weather conditions in the area of Kielce. Because of the description was based on assumptions and actual data, those assumptions were verifiable and based on strong statistical evidence supporting them in the long-term perspective in Kielce (40 years in this case). Thanks to this approach, it was able to compare data provided by ITU-R or ESA with real-time data (e.g. rain attenuation as a function of the rain rate). Moreover, this chapter presents the application of polynomial regressions to simply illustrate the influence of rainfall on the signal attenuation. Each datum was processed using a bilinear interpolation to achieve an improved evaluation from the adjacent grids for a selected region in Poland. These estimates may be used by satellite systems engineers to calculate the link budget analyses.
The monograph also deals with propagation concerns for satellite communications systems. The rainfall has a considerable influence on the quality of microwaves signals in the satellite communications systems, especially due to absorption and reflection, as hydrometeors act as a strong source of noise. All of data were used to identify the impact of rain intensity, polarization and radio waves frequency on the microwave satellite signal quality. The research results presented in the monograph can be useful to satellite engineers to improve the design and performance of satellite communication links, or to minimize the interruption or total lack of communication between the terminal and the satellite.