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Characteristics of the atmosphere of Mars for optical communication
Marčák, Tomáš ; Barcík, Peter (referee) ; Hudcová, Lucie (advisor)
The bachelor thesis is focused on the issue and research of atmosphere of the planet Mars for optical communication. The main goal of this thesis was to introduce the transmission through the atmosphere of the Mars and define possible wavelengths which could be used as possible communication. This thesis mainly introduces the optical communication and facts about the atmosphere of the planet. The main chapter presents more detailed analysis of composition of the atmosphere, the impact of the composition that is used for the radiation transmission. Lastly there are presented the results of the calculations and characteristics of the transmission through the Mars atmosphere. The next chapter is focused on theory of optical transmitters and its division. Subsequently, thesis describes the program for calculation of temporal, spatial and energetic characteristics of optical beam.
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BIT ERROR RATE AND AVAILABILITY OF THE ATMOSPHERIC OPTICAL LINKS
Kvíčala, Radek ; Vašinek, Vladimír (referee) ; Fišer, Ondřej (referee) ; Wilfert, Otakar (advisor)
This dissertation deals with the problematic of the free space optical link availability determination. For the presumption of the free space optical link unavailability we have to know statistical distribution of the atmospheric attenuations. In this work is also presented the measurement of these atmospheric attenuations with the specially designed optical link. Measurement is using switching of the two separate transmitters with wavelengths of 830 nm and 1550 nm. Presented statistic distribution let us determine the suitability of the link in the chosen locality during its design. Comparison of our measurement with other models like model based on the meteorological visibility is also presented. The last part of this work is focused on the preconditions for the hi-speed network bit error rate determination. Sample of the bit error rate measurement obtained by our designed bit error rate tester is attached.
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Model of atmospheric transmission media for free space optics
Přikryl, Petr ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
The aim of this thesis is to study the methods of a free space optical link design and its application in the communication technologies. The thesis describes possible intrusive influences on the transmitted optical signal, which are the signal noise, atmospheric attenuation and atmospheric turbulences. The thesis is particulary focused on the influence of the atmospheric turbulences and atmospheric attenuation on the optical beam.
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Characteristics of the atmosphere of Mars for optical communication
Marčák, Tomáš ; Barcík, Peter (referee) ; Hudcová, Lucie (advisor)
The bachelor thesis is focused on the issue and research of atmosphere of the planet Mars for optical communication. The main goal of this thesis was to introduce the transmission through the atmosphere of the Mars and define possible wavelengths which could be used as possible communication. This thesis mainly introduces the optical communication and facts about the atmosphere of the planet. The main chapter presents more detailed analysis of composition of the atmosphere, the impact of the composition that is used for the radiation transmission. Lastly there are presented the results of the calculations and characteristics of the transmission through the Mars atmosphere. The next chapter is focused on theory of optical transmitters and its division. Subsequently, thesis describes the program for calculation of temporal, spatial and energetic characteristics of optical beam.
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Earth-space path propagation characteristics in the climatic conditions of the Czech Republic from Alphasat Ka/Q band experiment
Fišer, Ondřej ; Brázda, Vladimír ; Pešice, Petr ; Grabner, M.
The objective of the activity is to prepare, realize and conduct experimental research of the influence of atmospheric phenomena on the Earth-space path propagation characteristics at 20 and 40 GHz (Ka/Q) bands in the specific climatic conditions of the Czech Republic (CR). The scientific approach is based on the comprehensive measurements of physical parameters of atmosphere together with concurrent measurements of propagation characteristics on the Earth-space path and on 10 collocated terrestrial paths with star configuration. The proposed activity will utilize the ESA Alphasat Mission Ka/Q experiment that is designed to investigate the propagation characteristics on slant paths in Europe and elsewhere.
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BIT ERROR RATE AND AVAILABILITY OF THE ATMOSPHERIC OPTICAL LINKS
Kvíčala, Radek ; Vašinek, Vladimír (referee) ; Fišer, Ondřej (referee) ; Wilfert, Otakar (advisor)
This dissertation deals with the problematic of the free space optical link availability determination. For the presumption of the free space optical link unavailability we have to know statistical distribution of the atmospheric attenuations. In this work is also presented the measurement of these atmospheric attenuations with the specially designed optical link. Measurement is using switching of the two separate transmitters with wavelengths of 830 nm and 1550 nm. Presented statistic distribution let us determine the suitability of the link in the chosen locality during its design. Comparison of our measurement with other models like model based on the meteorological visibility is also presented. The last part of this work is focused on the preconditions for the hi-speed network bit error rate determination. Sample of the bit error rate measurement obtained by our designed bit error rate tester is attached.
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Model of atmospheric transmission media for free space optics
Přikryl, Petr ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
The aim of this thesis is to study the methods of a free space optical link design and its application in the communication technologies. The thesis describes possible intrusive influences on the transmitted optical signal, which are the signal noise, atmospheric attenuation and atmospheric turbulences. The thesis is particulary focused on the influence of the atmospheric turbulences and atmospheric attenuation on the optical beam.
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Applied research at the Institute of Atmospheric Physics Prague
Fišer, Ondřej ; Jaroš, J. ; Brázda, V.
This article describes the research performed at the Milesovka observatory. The base of this research is the measurement of the signal attenuation on the experimental free space optic link. Concurrently the pertinent meteorological parameters are measured and compared to the attenuation. First of all, visibility, liquid water content, wind speed + other wind parameters and rain rate are sampled and statistically evaluated including diurnal variations.
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Rain impact on FSO link attenuation based on theory and measurement
Brázda, V. ; Schejbal, V. ; Fišer, Ondřej
The FSO link becomes a usual mean of modern wireless communications. But it suffers from atmospheric particles causing attenuation. That´s why this random attenuation must be carefully considered by the FSO link design. As it is known the most serious atmospheric phenomenon is fog, and low cloudiness. But the rain attenuation (night mare of mm wave links) is not negligible on optical links, too. In this contribution we focus on rain attenuation from theoretical as well as experimental point of view. Statistics and rain event analysis are shown. There is an overview and a comparison of several formulas for rain attenuation derived from DSD or rain rate. Rain is not the worst phenomena for the transmission but we can’t neglect its influence on FSO. Only full understanding of influence of real atmosphere can lead to solution of a high availability of FSO systems.
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