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External Part of the Receiving System for UHF Satellite signals
Sýkora, Jan ; Herceg, Erik (referee) ; Urbanec, Tomáš (advisor)
This bachelor thesis deals with omnidirectional antennas in the UHF band, especially Lindenblad’s omnidirectional antenna and its nulls in the radiation pattern. The aim was to design a preamplifier, power supply circuit and bias tee with the transmission of power supply, UHF signal and reference GPS signal through single coaxial cable towards a receiver. A further requirement was to design a mechanical part of the antenna which holds it together with considering modern manufacturing processes - 3D print. The final task was the measurement of antenna’s real parameters.
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Conceptual design of a polymeric gear tester in vacuum
Ptáček, Matyáš ; Šperka, Petr (referee) ; Černohlávek, Mikuláš (advisor)
The bachelor thesis deals with the conceptual design of a polymeric gear tester in vacuum. Using a test device, it is possible to test the coefficient of friction in gears. At the beginning of the work is described the issue of operating conditions of satellites in low orbit together with the effects that affect them. Subsequently, suitable polymeric materials are selected, and current publicly available test rigs are described. Based on the research, two conceptual designs are made, one of them is selected and described in detail at the end of the work.
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Linear Transponder Model
Pospíšil, Miroslav ; Ondráš, Radek (referee) ; Baran, Ondřej (advisor)
This master’s thesis deals with satellite transponders. Firstly, satellite communication basics, satellite services definitions, frequency bands and satellite orbits are investigated. The second chapter forms the satellite transponders analysis. The transparent transponder and the transponder with on-board processing are described. Finally, a transponder model is designed and simulated in communication chain.
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Folding mechanism for mobile satellite antenna
Buchta, Tomáš ; Koutecký, Tomáš (referee) ; Brandejs, Jan (advisor)
The aim of this bachelor thesis is the design and construction of a manipulating mechanism for a satellite antenna, mainly for use on vehicles that will be able to work even in adverse weather conditions. The design and manufacturing of the device should provide sufficient positioning accuracy and toughness of the structure. Since this is a prototype therefore the design solutions should be chosen with regard to simplicity of production.
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Satellite refuelling mission proposal
Čuda, Adam ; Daněk, Vladimír (referee) ; Krepl,, Ondřej (advisor)
Tato diplomová práce se zabývá problematikou doplňování paliva družicím na orbitě. V práci je popsán koncept doplňování paliva na orbitě společně s přehledem misí a technologií zabývajících se doplňováním paliva a prodloužením životnosti. Jsou uvedena specifika mise pro doplnění paliva, potřeby a omezení platné pro danou misi na základě kterých je formulováno programové prohlášení. Je představen návrh mise na doplnění paliva dále rozpracovávající požadavky mise a koncepci operací. Návrh zarhnuje možné klíčové vybavení pro misi. Tato práce přináší popis doplňování paliva družic na orbitě a představuje návrh mise určené k výkonu tohoto úkolu. Na základě této práce je možné navrhnout kosmickou družici určenou k zásobování jiných družic palivem.
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Synchronization of the time using the GPS
Švábeník, Petr ; Šmíd, Petr (referee) ; Vyskočil, Pavel (advisor)
This thesis discusses about using the worldwide satellite system GPS for time and frequency synchronization. This thesis presents study about basic principles of the GPS system, its segments and ways of using this system. Some GPS receivers suitable for receiving the time marks (pulses) used for time synchronization are described. Thesis contents designing of the circuit that will receive time marks and it will digitalize and record external signal and send it with precision time information to PC for displaying and post processing. Thesis also discusses about both hardware and software development of the synchronization module and software used in PC.
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Monitoring rozšiřování plantáží palmy olejné v Nikaragui pomocí metod dálkového průzkumu Země
Mezihoráková, Tereza
The first part of this bachelor's thesis is literature research that discusses the expansion of oil palm plantations in Central America, as well as remote sensing and monitoring of forest and agricultural areas using its methods. The practical part deals with the monitoring of oil palm plantations between 2017 and 2022 using satellite data. The analysed area was the Kukra Hill region located in the state of Nicaragua. PlanetScope multispectral images were used for the analysis. First, vegetation indices were calculated, classifications were made, the areas of plantations in the given years were determined and their comparison was made. In 2017, the area of oil palm plantations within the area of interest was 4,109 ha, but of this area, 445 ha disappeared by 2022, so 3,664 ha were preserved from 2017 to 2022. In 2022, the area of plantations was already 8,512 ha, which means that the area of oil palm plantations increased by 4,848 ha between the given years. The used methodology can also be used in other areas with similar geographical conditions, where oil palm plantations are expanding and will contribute to better monitoring of the studied phenomenon.
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Analýza vybraných W obohacených repetic u předivky brslenové \kur{Yponomeuta cagnagella} (Lepidoptera)
PILÍKOVÁ, Aneta
This thesis focuses on the repetitive sequences located in the W chromosome of the spindle ermine moth (Yponomeuta cagnagella) (Lepidoptera). The copy number of the selected repeats was established in male and female genomes from two geographic populations using real-time PCR (qPCR). Fluorescence in situ hybridization (FISH) was used to localize these sequences in female pachytene nuclei. The satellite tandem repeat and the transposon Maverick are present in the W chromosome in high copy numbers. In contrast to previously conducted bioinformatical analyses, the rDNA cluster is probably localized in an autosome in Y. cagnagella. The Maverick transposon was detected in both extensive terminal regions of the W chromosome.
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