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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Posicionamento relativo: análise dos resultados combinando as observáveis L1 dos satélites GPS e SBAS. / Positioning on analysis of the results of combining observable L1 GPS satellites and SBAS.

Albarici, Fabio Luiz 08 April 2011 (has links)
Os sistemas de aumento, conhecidos como SBAS (Satellite-Based Augmentation System) fornecem informações de integridade e acurácia em tempo real para seus usuários, utilizando-se das correções diferenciais que são transmitidas pelos satélites geoestacionários e estão disponíveis em algumas regiões do globo terrestre. Fora da sua região de abrangência o sistema ainda não disponibiliza os dados de correção em tempo real. Entretanto, o sinal é transmitido na mesma frequência L1 do GPS, o qual fica disponível aqui no Brasil, e alguns receptores GNSS possuem canais de frequência especifica que captam este sinal, com a perspectiva de que os dados destes satélites melhoram as condições do rastreio, além da melhoria na acurácia das coordenadas. Partindo deste princípio, foi utilizada a observável fase da onda portadora (L1) para inferir sobre a sua contribuição para o posicionamento. Os rastreios foram realizados em diferentes localidades devido à elevação dos satélites SBAS variar em função da latitude e longitude. Contudo, este estudo foi direcionado para os dados dos satélites PRN 138 (WAAS), PRN 120 e 124 (EGNOS), pois foram os únicos visíveis durante todo o rastreio, tendo simultaneidade dos dados entre os receptores base e móvel. Durante a etapa de processamento, o qual foi utilizado o software GNSS Solution, alguns experimentos foram realizados, tais como: 1) Processamento com todas as observáveis L1 dos satélites disponíveis (GPS e SBAS), análise dos desvios-padrão e comparação das coordenadas obtidas com as consideradas verdadeiras; 2) Processamento sem as observáveis L1 dos satélites SBAS, análises e comparações; 3) Retirada gradativa dos satélites GPS e reprocessamento em conjunto (GPS+SBAS) e separadamente (apenas GPS). A finalidade principal desses experimentos foi verificar a potencialidade da observável L1 dos satélites SBAS processadas em conjunto com a observável L1 do GPS, no posicionamento relativo. Análises estatísticas, como tendência e erro médio quadrático (RMS), foram aplicadas para verificar a existência de erros sistemáticos e a acurácia das coordenadas. Os resultados mostram que, especificamente nos locais de rastreio, as observáveis L1 dos satélites SBAS ao serem adicionados ao processamento, combinado com as observáveis L1 dos satélites GPS, não são determinantes para melhoria da acurácia das coordenadas. / The augmentation systems, known as SBAS (Satellite-Based Augmentation System) provide information for completeness and accuracy in real time to its users, using the differential corrections that are transmitted by geostationary satellites. They are available in specific regions of the globe such as USA, Canada and Europe. Outside their region of coverage the system still does not provide the correction data in real time. However, the signal is transmitted at the same frequency L1 GPS, which is available here in Brazil, and some GNSS receivers have specific frequency channels that capture this signal, with the prospect that the data from these satellites improve the conditions of screening, besides improving the accuracy of the coordinates. With this assumption, we used the observed phase of the carrier wave (L1) to infer its contribution to the placement. The surveys were conducted in various locations due to rising SBAS satellites vary with latitude and longitude. However, this study was directed to the data from the WAAS satellites (PRN 138) and EGNOS (PRN 120 and 124) because they were the only visible throughout the screening taking simultaneity between the base and mobile receivers. During the processing stage, which was used the software GNSS Solution, some experiments were performed, such as: 1) Processing with all the L1 observable from available satellites (GPS and SBAS), analysis of standard deviations and comparison of the coordinates obtained with the true, 2) processing without observable L1 SBAS satellites, analysis and comparisons, 3) gradual withdrawal of the GPS satellites and reprocessing together (GPS + SBAS) and separately (GPS only). The main purpose of these experiments was to investigate the potential of the L1 observable processed SBAS satellites together with GPS L1 observable in the relative positioning. Statistical analysis such as trending and root mean square (RMS) were applied to verify the existence of systematic errors and accuracy of these coordinates. The results show that, specifically at sites of screening, the observables L1 SBAS satellites to be added to the processing, combined with the L1 observable GPS satellites, are not decisive for improving the accuracy of the coordinates.
2

Posicionamento relativo: análise dos resultados combinando as observáveis L1 dos satélites GPS e SBAS. / Positioning on analysis of the results of combining observable L1 GPS satellites and SBAS.

Fabio Luiz Albarici 08 April 2011 (has links)
Os sistemas de aumento, conhecidos como SBAS (Satellite-Based Augmentation System) fornecem informações de integridade e acurácia em tempo real para seus usuários, utilizando-se das correções diferenciais que são transmitidas pelos satélites geoestacionários e estão disponíveis em algumas regiões do globo terrestre. Fora da sua região de abrangência o sistema ainda não disponibiliza os dados de correção em tempo real. Entretanto, o sinal é transmitido na mesma frequência L1 do GPS, o qual fica disponível aqui no Brasil, e alguns receptores GNSS possuem canais de frequência especifica que captam este sinal, com a perspectiva de que os dados destes satélites melhoram as condições do rastreio, além da melhoria na acurácia das coordenadas. Partindo deste princípio, foi utilizada a observável fase da onda portadora (L1) para inferir sobre a sua contribuição para o posicionamento. Os rastreios foram realizados em diferentes localidades devido à elevação dos satélites SBAS variar em função da latitude e longitude. Contudo, este estudo foi direcionado para os dados dos satélites PRN 138 (WAAS), PRN 120 e 124 (EGNOS), pois foram os únicos visíveis durante todo o rastreio, tendo simultaneidade dos dados entre os receptores base e móvel. Durante a etapa de processamento, o qual foi utilizado o software GNSS Solution, alguns experimentos foram realizados, tais como: 1) Processamento com todas as observáveis L1 dos satélites disponíveis (GPS e SBAS), análise dos desvios-padrão e comparação das coordenadas obtidas com as consideradas verdadeiras; 2) Processamento sem as observáveis L1 dos satélites SBAS, análises e comparações; 3) Retirada gradativa dos satélites GPS e reprocessamento em conjunto (GPS+SBAS) e separadamente (apenas GPS). A finalidade principal desses experimentos foi verificar a potencialidade da observável L1 dos satélites SBAS processadas em conjunto com a observável L1 do GPS, no posicionamento relativo. Análises estatísticas, como tendência e erro médio quadrático (RMS), foram aplicadas para verificar a existência de erros sistemáticos e a acurácia das coordenadas. Os resultados mostram que, especificamente nos locais de rastreio, as observáveis L1 dos satélites SBAS ao serem adicionados ao processamento, combinado com as observáveis L1 dos satélites GPS, não são determinantes para melhoria da acurácia das coordenadas. / The augmentation systems, known as SBAS (Satellite-Based Augmentation System) provide information for completeness and accuracy in real time to its users, using the differential corrections that are transmitted by geostationary satellites. They are available in specific regions of the globe such as USA, Canada and Europe. Outside their region of coverage the system still does not provide the correction data in real time. However, the signal is transmitted at the same frequency L1 GPS, which is available here in Brazil, and some GNSS receivers have specific frequency channels that capture this signal, with the prospect that the data from these satellites improve the conditions of screening, besides improving the accuracy of the coordinates. With this assumption, we used the observed phase of the carrier wave (L1) to infer its contribution to the placement. The surveys were conducted in various locations due to rising SBAS satellites vary with latitude and longitude. However, this study was directed to the data from the WAAS satellites (PRN 138) and EGNOS (PRN 120 and 124) because they were the only visible throughout the screening taking simultaneity between the base and mobile receivers. During the processing stage, which was used the software GNSS Solution, some experiments were performed, such as: 1) Processing with all the L1 observable from available satellites (GPS and SBAS), analysis of standard deviations and comparison of the coordinates obtained with the true, 2) processing without observable L1 SBAS satellites, analysis and comparisons, 3) gradual withdrawal of the GPS satellites and reprocessing together (GPS + SBAS) and separately (GPS only). The main purpose of these experiments was to investigate the potential of the L1 observable processed SBAS satellites together with GPS L1 observable in the relative positioning. Statistical analysis such as trending and root mean square (RMS) were applied to verify the existence of systematic errors and accuracy of these coordinates. The results show that, specifically at sites of screening, the observables L1 SBAS satellites to be added to the processing, combined with the L1 observable GPS satellites, are not decisive for improving the accuracy of the coordinates.
3

Možnosti zvyšování výkonnosti GNSS pro zajištění provozu RNP-RNAV / Ways of Improving GNSS Performance for RNP-RNAV Operations

Kvíčala, Aleš January 2008 (has links)
The goal of this thesis is to analyze current requirements of navigation system RNP RNAV. Particularly is behaving about estimation current ways and description of future improving GNSS performance. In submitted thesis is describes present evolution of area navigation and required navigation performance RNP. The next part deals with the common access how to raise the performance parameters, their estimation and also description how it'll be solve in future systems.
4

Problematika zavedení IFR provozu na malá letiště v ČR / The issue of the introduction of IFR operations at small airports in the Czech Republic

Minčík, Igor January 2015 (has links)
This master‘s thesis is focused on the evaluation of conditions for IFR operations in the Czech Republic and their neighbours. The thesis is also focused on evaluation of posibilities of IFR navigation for small airports. In this context part of thesis is dedicated to a modern way of navigation using GNSS.
5

[en] EFFECT OF THE IONOSPHERE OF LOW LATITUDES IN GPS: SBAS (GLOBAL SYSTEM POSITIONING - SPACE BASED AUGMENTATION SYSTEM) / [pt] EFEITOS DA IONOSFERA DE BAIXAS LATITUDES NO GPS: SBAS (GLOBAL POSITIONING SYSTEM - SPACE BASED AUGMENTATION SYSTEM)

JOSE ANTONIO G PAIVA 07 January 2005 (has links)
[pt] A ionosfera de baixas latitudes tem características que poderiam causar problemas à operação do GPS/SBAS. Entre elas se encontra a anomalia equatorial, cuja densidade eletrônica pode apresentar intensos gradientes horizontais (e, portanto, no índice de refração do meio). Estes gradientes podem ser intensos o suficiente para introduzir erros nas previsões resultantes do GPS/SBAS. Para avaliar este problema, foi desenvolvido um programa de simulação em computador que integra modelos para: (i) a previsão das posições dos satélites da constelação GPS; (ii) a evolução temporal e espacial da densidade eletrônica da ionosfera equatorial; e (iii) uma rede de estações de referência de posições fornecidas para analisar os efeitos da anomalia equatorial sobre os erros causados pela ionosfera nos sinais dos satélites GPS recebidos pelas estações. Em cada passo da simulação, diversos procedimentos são realizados. Estes procedimentos são repetidos um grande número de vezes e, ao final da simulação, estatísticas dos erros são apresentadas. Este programa de simulação em computador foi utilizado para analisar a influência do número de estações de referência, assim como de suas localizações, nos erros de posicionamento de aeronaves. / [en] The low-latitude ionosphere has some features that could cause problems even to the joint GPS/SBAS operation. Among them, one finds the equatorial anomaly, whose electronic density - and thus its refractive index - can present intense horizontal gradients. These gradients can be intense enough to induce errors in the predictions by the GPS/SBAS. To analyze this problem, a computer simulation program has been developed. This program integrates models for: (i) forecasting the satellite orbital positions of the GPS constellation; (ii) the temporal and spatial evolution of the electronic density of the low-latitude ionosphere; and (iii) a given network of reference stations to analyze the effects of the equatorial anomaly on the GPS satellite signals received by the stations and users. In each step of the simulation, several procedures are performed. These procedures are repeated several times and, at the end of the simulation, error statistics are presented. This computer simulation program has been used to analyze the influence of the equatorial anomaly and of the number and layout of reference stations upon the errors in aircraft positions provided by the GPS/SBAS.
6

Análisis del sistema de navegación por satélite europeo EGNOS para su integración con VRS

Olivares Belinchon, Jesús Lorenzo 21 March 2016 (has links)
[EN] Abstract Global Navigation Satellite Systems (GNSS) have transformed the positioning and navigation techniques, becoming the indispensable today for multiple applications. Satellite navigation is one of the new forms of navigation and has multiple advantages over existing techniques. It can provide information to users in any location, without direct vision and comprehensively worldwide. Therefore, we are witnessing the arrival of a navigation system that, by itself, could give boaters the ability to perform positioning and route planning without the need to resort to another method or additional information. The International Civil Aviation Organization (ICAO) began in early 1990 a series of activities to define "air navigation system of the future", whose base would be the GNSS systems. The potential applicability of these systems is a reality, fulfilling the requirements of many operations navigation: accuracy, integrity, availability and continuity. One example that is already being used for CAT III operations, such as aircraft landing. The signal emitted by satellites undergoes a series of errors in its spread and the operating system to be limited for many applications. Therefore, the real-time positioning requires the use of a differential corrections to improve the performance of GNSS systems. Current differential correction systems can be grouped in local systems or LADGPS (Local Area DGPS), and extensive systems or WADGPS area (Wide Area DGPS). In March 2011 the European Commission declared the 'Safety-of-Life' service of EGNOS suitable for use in civil aviation, which is the WADGPS system used in this research together with the System of Permanent Reference Stations VRS, as system LADGPS. The objective of this thesis is the analysis of the possible integration of EGNOS navigation system with positioning methodology from ground Reference Stations Trimble VRS. It aims to improve the positioning accuracy of the EGNOS system implementing a priori more accurate VRS solution. In short, we seek a proposed methodology of positioning that has the best of both, we call EGNOS / VRS. Having defined the methodology to be used for determining the positioning EGNOS / VRS new performances are analyzed and improved accuracy is verified, allowing use is new methodology for applications with requirements for positioning accuracy, such as in agriculture precision. / [ES] Resumen Los Sistemas Globales de Navegación por Satélite (GNSS) han transformado las técnicas de posicionamiento y navegación, llegando a ser en la actualidad indispensable para múltiples aplicaciones. La navegación por satélite es una de las nuevas formas de navegación y tiene múltiples ventajas sobre las técnicas existentes. Puede proporcionar información a los usuarios en cualquier ubicación, sin necesidad de visión directa y de forma global en todo el planeta. Por tanto, estamos asistiendo a la llegada de un sistema de navegación que, por sí mismo, podría proporcionar a los navegantes la capacidad de realizar el posicionamiento y la planificación de rutas sin la necesidad de recurrir a otro método o información adicionales. La Organización de Aviación Civil Internacional (OACI) inició a principios de 1990 una serie de actividades encaminadas a definir el "sistema de navegación aérea del futuro", cuya base serían los sistemas GNSS. La aplicabilidad potencial de estos sistemas es ya una realidad, cumpliendo los requerimientos de muchas operaciones de navegación: precisión, integridad, disponibilidad y continuidad. Sirva como ejemplo que se está utilizando ya para operaciones de CAT III, como el aterrizaje de aeronaves. La señal que emiten los satélites sufre una serie de errores en su propagación y funcionamiento del sistema que los limitan para muchas aplicaciones. Por ello, el posicionamiento en tiempo real necesita de la utilización de unas correcciones diferenciales que mejoran el rendimiento de los sistemas GNSS. Los sistemas actuales de corrección diferencial los podemos agrupar en sistemas locales o LADGPS (Local Area DGPS), y sistemas de área extensa o WADGPS (Wide Area DGPS). En marzo de 2011 la Comisión Europea declaró el servicio 'Safety-of-Life' de EGNOS apto para su uso en aviación civil, siendo éste el sistema WADGPS utilizado en esta investigación junto con el sistema de Estaciones de Referencia Permanentes por VRS, como sistema LADGPS. El Objetivo de ésta Tesis es el análisis de la posible integración del sistema de navegación EGNOS con la metodología de posicionamiento a partir de Estaciones de Referencia en tierra VRS de Trimble. Se pretende mejorar la precisión de posicionamiento del sistema EGNOS implementando la solución VRS, a priori más precisa. En definitiva, buscamos una propuesta de metodología de posicionamiento que tenga lo mejor de ambas, que llamaremos EGNOS/VRS. Una vez definida la metodología a emplear para la determinación del posicionamiento EGNOS/VRS se analizan los nuevos rendimientos y se verifica la mejora de precisión, lo que permite utilizar está nueva metodología para aplicaciones con más requisitos en exactitud de posicionamiento, como por ejemplo en agricultura de precisión. / [CAT] Resum Els Sistemes Globals de Navegació per Satèl¿lit (GNSS) han transformat les tècniques de posicionament i navegació, arribant a ser en l'actualitat indispensable per a múltiples aplicacions. La navegació per satèl¿lit és una de les noves formes de navegació i té múltiples avantatges sobre les tècniques existents. Pot proporcionar informació als usuaris en qualsevol ubicació, sense necessitat de visió directa i de forma global en tot el planeta. Per tant, estem assistint a l'arribada d'un sistema de navegació que, per si mateix, podria proporcionar als navegants la capacitat de realitzar el posicionament i la planificació de rutes sense la necessitat de recórrer a un altre mètode o informació addicionals. L'Organització d'Aviació Civil Internacional (OACI) va iniciar a principis de 1990 una sèrie d'activitats encaminades a definir el "sistema de navegació aèria del futur", la base del qual serien els sistemes GNSS. L'aplicabilitat potencial d'estos sistemes és ja una realitat, complint els requeriments de moltes operacions de navegació: precisió, integritat, disponibilitat i continuïtat. Servisca com a exemple que s'està utilitzant ja per a operacions de CAT III, com l'aterratge d'aeronaus. El senyal que emeten els satèl¿lits patix una sèrie d'errors en la seua propagació i funcionament del sistema que els limiten per a moltes aplicacions. Per això, el posicionament en temps real necessita de la utilització d'unes correccions diferencials que milloren el rendiment dels sistemes GNSS. Els sistemes actuals de correcció diferencial els podem agrupar en sistemes locals o LADGPS (Local Àrea DGPS) , i sistemes d'àrea extensa o WADGPS (Wide Àrea DGPS) . Al març de 2011 la Comissió Europea va declarar el servici 'Safety-of-Life' d'EGNOS apte per al seu ús en aviació civil, sent este el sistema WADGPS utilitzat en esta investigació junt amb el sistema d'Estacions de Referència Permanents per VRS, com a sistema LADGPS. L'Objectiu d'esta Tesi és l'anàlisi de la possible integració del sistema de navegació EGNOS amb la metodologia de posicionament a partir d'Estacions de Referència en terra VRS de Trimble. Es pretén millorar la precisió de posicionament del sistema EGNOS implementant la solució VRS, a priori més precisa. En definitiva, busquem una proposta de metodologia de posicionament que tinga el millor d'ambdós, que cridarem EGNOS/VRS. Una vegada definida la metodologia a emprar per a la determinació del posicionament EGNOS/VRS s'analitzen els nous rendiments i es verifica la millora de precisió, la qual cosa permet utilitzar està nova metodologia per a aplicacions amb més requisits en exactitud de posicionament, com per exemple en agricultura de precisió. / Olivares Belinchon, JL. (2016). Análisis del sistema de navegación por satélite europeo EGNOS para su integración con VRS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61981 / TESIS
7

Trendy modernizace technologií pro řízení letů v okolí civilních letišť / Trends of modernization of the technologies intended for flight control in vicinity of an aerodrome

Buľák, Marián January 2019 (has links)
This master’s thesis deals with technologies intended for flight control during approach and landing. The main focus is on perspective approach systems, including differential technology systems. The thesis is to serve as a study aid for pilots and students of Air Traffic study programme. The main aim of this thesis is to create a qualified whole of perspective and used approach systems. Individual systems include basic characteristics and assessment of their future use. The thesis also includes an analysis of the possibility of implementing the DGNSS system at the airport with multiple runways. Prague-Ruzyně airport was chosen for this purpose. The implementation of this system is compared to other precision approach systems.
8

Technologie automatického řízení civilního letadla po trajektorii přibližování na přistání / Technology of aircraft automatic flight control along an approach trajectory

Kočiš, Martin January 2020 (has links)
This diploma thesis is focused to systems used for automatic control of civil aircraft along an precision approach trajectory. It describes precision approach systems used in the past and their evolutional steps leading to their current and future configuration. The thesis does not put the goal to be a detailed study but to be a publication providing to pilots and students of Aeronautical traffic the introduction to the field of precision approach systems in context to another fields of aeronautical traffic, describing its current status and infer its further development.
9

Testování propojení komponent systému GBAS / GBAS interconnection and testing

Polok, Zbyszek January 2016 (has links)
This thesis deals with the problem of GNSS. The document will attempt to illustrate some possible sources of error and their corrections. The main characteristics of SBAS and GBAS are described. The aim of this work is to design GBAS interconnection
10

Seasonal permafrost subsidence monitoring in Tavvavuoma (Sweden) and Chersky (Russia) using Sentinel-1 data and the SBAS stacking technique

Rehn, Ida January 2022 (has links)
Permafrost deformation is expected to increase due to climatic perturbations such as amplified air and soil temperatures, resulting in permafrost thawing and subsequent subsidence. Palsas and peat plateaus are uplifted ice-rich peat mounds that experience permafrost subsidence. This is due to the uppermost layer of permafrost, known as the Active Layer (AL), that seasonally thaws and freezes. Interferometric Synthetic Aperture Radar (InSAR) is an interferometric stacking technique successfully applied over permafrost regions when monitoring ground subsidence. The Small Baseline Subset (SBAS) technique is based on interferograms produced by stacking Synthetic Aperture Radar (SAR) acquisitions with small normal baselines. In this study, seasonal Sentinel-1 SAR C-band data obtained during June, July, August and September (JJAS) was used to generate seasonal Line of Sight (LoS) deformation time series of palsas and peat plateaus in Tavvavuoma (Sweden) by using the SBAS technique. Chersky (Russia) has documented permafrost subsidence and was used as a reference site. Findings include that seasonal stacks with short normal baselines generated more robust results than inter-annual stacks with longer normal baselines and temporal data gaps. No instances of pronounced subsidence were reported during JJAS. Nevertheless, minor subsidence during the early season and negative development trends were identified in the Tavvavuoma 2020 andChersky 2020-2021 stacks, respectively. Increased subsidence during the mid-and late thaw season was detected. The SBAS technique performed better and resulted in less temporal and seasonal decorrelation in areas above the tree line (Tavvavuoma) compared to the lowlands in the forest-tundra (Chersky). The challenge lies in whether surface subsidence of palsas and peat plateaus in sporadic permafrost regions experience irreversible long-term changes or seasonally cyclic changes in the permafrost ground regime. Future studies are recommended to implement annual intervals, including winter images over Tavvavuoma.

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