|
|
Real Time Suppression of Atmospheric Turbulence
Macků, Jiří ; Orság, Filip (referee) ; Marvan, Aleš (advisor)
This paper deals with removing undesirable image deformations caused by turbulences of Earth's atmosphere. The goal is to design and implement algorithm for suppression of atmosphere turbulence in video sequences to use in long-distance camera monitoring system. This paper also focuses on optimization of existing algorithms for running in real-time. Algorithm will be implemented in C++ programming language with use of library for computer vision OpenCV.
|
|
|
High precision differential thermometer
Sieklik, Ivan ; Wilfert, Otakar (referee) ; Barcík, Peter (advisor)
This work describes the principles of measurements of refractive-index structural parameter. This parameter represent intensity of atmospheric turbulence which is measured by a differential temperature meter. Basic properties of atmospheric transmission environment are specified and their influence on optical wave is stated. Furthermore, this thesis also describes fundamental types of sensors dedicated to temperature measurements. The aim of this work was to create a differential temperature meter which is able to measure the refractive-index structural parameter.
|
|
|
Prediction of the atmospheric turbulence
Sloboda, Šimon ; Barcík, Peter (referee) ; Hudcová, Lucie (advisor)
The aim of this work is to examine theoretical knowledge of the refractive index structure parameter and models for its calculation and prediction. Based on data downloaded from meteorological services, the accuracy of refractive index structure parameter prediction using Sadot-Kopeika model was evaluated at ten different locations on Earth. A program was created for the calculation and prediction of the refractive index structure parameter, which uses downloaded meteorological data.
|
|
|
Prediction of the atmospheric turbulence
Sloboda, Šimon ; Barcík, Peter (referee) ; Hudcová, Lucie (advisor)
The aim of this work is to examine theoretical knowledge of the refractive index structure parameter and models for its calculation and prediction. Based on data downloaded from meteorological services, the accuracy of refractive index structure parameter prediction using Sadot-Kopeika model was evaluated at ten different locations on Earth. A program was created for the calculation and prediction of the refractive index structure parameter, which uses downloaded meteorological data.
|
|
|
Interferometric measurement of phase changes of optical beam in turbulence
Děcká, Klára ; Křivák,, Petr (referee) ; Hudcová, Lucie (advisor)
This master’s thesis deals with the impact of atmospheric turbulence on phase changes of a free space optical signal. This problematic is investigated by the interferometric method. A part of the thesis is focused on the phenomenon of atmospheric turbulence. Then the physical effect of interference is discussed and optical interferometers are described. The experimental part of the thesis is focused on measurement of phase shift of optical signal by interferometric method. The result of the thesis is to determine how phase shift of an optical beam depends on the strength of turbulence.
|
|
|
Laser beam coherence in turbulent atmosphere
Polanský, David ; Drexler, Petr (referee) ; Hudcová, Lucie (advisor)
In the first part of the thesis discusses the function of the laser design and construction of its class. Here is an explanation of coherence and other properties of laser radiation. Listed below are the possibilities of energy distribution in the laser beam. Described in particular Gaussian beam. The paper explains the phenomena of bending and Young's experiment. The paper examines the influence of atmospheric environment in the transmission of electromagnetic waves, defined as light. Particular attention is devoted to atmospheric turbulence. In the second part are first discussed the possibility of measuring atmospheric turbulence and coherence of laser beam parameters. The following is designed to measure workplace coherence width and coherence length in a turbulent environment. At these workplaces were measured. The results of these measurements are also listed in the job. The following comparison of results with theoretical values.
|
|
|
Power Budget of the Laser Rangefinder
Kotol, Martin ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
The thesis analyzes the optical laser range finders in real propagation environments. Itdescribes the various parts of optical laser range finders their properties and principles in relation to their performance balance. The paper presents the basic optical properties of lenses used in the transmitter and receiver. A separate chapter is devoted to the transit time method and factors influencing the measurement. The proportional directional reflectance analysisis a part of the thesis. In conclusion, the thesis contains the practical laboratory measurements of the relative directional reflectance of different materials and colors, and verification of the power level diagram.
|
|
|
Communication protocols for Free-Space Optical links
Šedo, Ondrej ; Kincl, Zdeněk (referee) ; Kolka, Zdeněk (advisor)
This master’s thesis is focused on behaviour of the TCP/IP protocol on free-space optical link which is affected by the effect of atmospheric turbulence. This causes fluctuation of the received optical power and therefor bit error rate changes. In the simulation model short-time bit error rate is calculated from random generated received optical signal and then used in time-domain analysis of the OMNeT++ network simulator. A buffer in transmitter is designed based on simulation results. It pauses the data transmitting in cases of FSO link outage. This method is then implemented into FPGA device.
|
|
|
Optimal Intensity Distribution in a Laser Beam for FSO Communications
Barcík, Peter ; Capsoni, Carlo (referee) ; Číp, Ondřej (referee) ; Wilfert, Otakar (advisor)
Dizertačná práca je zameraná na štúdium a analýzu rozloženia optickej intenzity v laserovom zväzku v rovine vysielacej (TXA) a prijímacej apertúry (RXA), ktorý podlieha zmenám ako pri šírení voľným priestorom, tak pri šírení atmosférou. Cieľom práce je nájsť optimálne rozloženie optickej intezity v rovine vysielacej apertúry, ktoré bude minimálne ovplyvnené apertúrou vysielača a atmosférickými turbulenciami. Za účelom analýzy šírenia optickej vlny atmosférou bola využitá simulácia založená na metóde Split-Step. Šírenie Flattened Gaussian zväzku bolo analyzované pre režim slabých a stredných turbulencií. Práca sa zaoberá použitím multimódového vlákna s veľkým priemerom jadra ako tvarujúceho elementu a obsahuje návrh refrakčného tvarovača, pomocou ktorého je možno konvertovať Gaussovský zväzok na zväzok s uniformným rozložením optickej intenzity. Nakoniec je pomocou získaných poznatkov zostavený plne fotonický vysielač a prijímač, ktorých použitie spočíva v generovaní a príjmaní optickej koherentnej vlny prenášajúcej presnú fázu.
|
|
|
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.
|
guest ::
