Till recently, no significant attempts have been made of developing Aircraft Based Augmentation System (ABAS) architectures capable of generating integrity signals suitable for safety-critical GNSS applications and no commercial ABAS products are available at present. The aim of this research is to support the design a system that generates integrity signals suitable for GNSS application. The conceptual design and key mathematical models were recently developed by the Italian Air Force Experimental Flight Test Centre (CSV-RSV) [1, 2]. Such a system, would be able to provide steering information to the pilot, allowing for real-time and continuous integrity monitoring, avoidance of safety/mission-critical flight conditions and fast recovery of the required navigation performance in case of GNSS data losses. The key elements addressed in this thesis are the development of a CATIA model for military and civil aircraft, supporting antenna obscuration and multipath analysis. This is to allow the ABAS system to generate suitable integrity flags when satellites signals are lost. In order to analyse the GNSS signal loss causes, the GNSS constellation models, the flight dynamics models, fading models, multipath models, Doppler shift models, and GNSS receiver tracking technology previously developed by CSV-RSV, are considered in this research.

Detta examensarbete utfördes under våren 2009 och avhandlar bestämning av fixpunkter i ett höjdnät med hjälp av statiska Global Navigation Satellite System (GNSS) mätningar. Ämnet är högaktuellt med tanke på att många kommuner står inför en övergång till Rikets Höjdsystem 2000 (RH 2000). Det kan vara ett problem vid en sådan övergång om det finns isolerade delar av det lokala höjdnätet som inte är anslutet till huvudnätet. Tidigare har den enda lösningen på ett sådant problem varit att genomföra ett höjdavvägningståg, ett både kostsamt och tidskrävande företag. Syftet med denna studie är att ge svar på hur noggrant det går att göra en höjdbestämning av fixpunkter med statisk GNSS-mätning.  Fältarbetet har utförts i Sandvikens kommun där ett antal höjdfixpunkter i RH 2000 nätet använts som referens vid GNSS-mätningar. Ett nät bestående av sju mätpunker etablerades i anslutning till RH 2000 höjdfixar. Fem av dessa användes sedan som passpunkter för att höjdbestämma två centralt belägna mätpunkter i nätet. För kontroll av mätningarna användes den kända avvägda höjden på de sökta punkterna. Mätningarna utfördes med fyra stycken Leica GX1230+ GNSS-mottagare som etablerades på punkterna i tre fyratimmarssessioner. Mätningarna utfördes i två kampanjer med tre veckors mellanrum. Efterberäkning av GNSS- mätdata gjordes med Leica Geo Office 7 (LGO 7) och Surfer 8. Kontroll av resultaten gjordes genom matrisberäkningar i Microsoft Excel. Resultaten baseras på en sammanslagning av de båda mätkampanjerna. Avvikelserna visade sig ligga i ett spann på ca 3–5 mm ± punktmedelfelet (σH) lägre än de precisionsavvägda RH 2000 höjderna. Det faktum att samtliga GNSS-mätta höjder ligger 3–5 mm lägre än officiella RH 2000-höjder tyder på att ett systematiskt fel upptäckts. Slutligen, visar detta arbete att genom att kombinera frekvenser kan medelfelet bli så bra som 3 mm vid höjdbestämning med hjälp av statisk GNSS-mätning.

The purpose of this report is to analyze the advantages of using programme software to monitor masshauling instead of using the conventional method. A comparsion between different programs will also be conducted in an attempt to determine the most affordable. This report is written for NCC Construction AB to help them choose a software most fitting for future projects.The report is based upon literature such as information taken from the developers website, existing reports with similar context, interviews with sellers of the software and interviews with people working in the building sector.The result of this report shows that there are several advantages with investing in a software that helps the management of a project and that it is something that should be taken under consideration instead of the existing method. Topcon is a clear favorite following the inquiries comparisons as done, when they deliver a complete system and not only a supplement to the current approach. Scanlaser are just in the beginning of its development, and is so far only out with an early version of the software, while Topcon has been brought further in development and therefore has more features in the program. To utilize Topcon we fully recommend that the device HT-30 is used.

Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2008.

This thesis examines the current implementations for the distribution of real-time GNSS data over IP networks such as the public Internet, focusing on two essential components of the system, data format and transport protocol. The provision of a suitable data format will allow users to take full advantage of the real-time GNSS data distribution system. Types of GNSS supported, message sizes, data rates, data precision levels, hardware and software support and possible future developments are investigated. An analysis is carried out on commonly known GNSS data formats, highlighting the most suitable standard for each evaluation criterion. A similar investigation is carried out on the transport protocols. An analysis is conducted on various design aspects of NTRIP and RT-IGS protocols, covering factors such as data latency, integrity, firewalls and proxy server compatibility and scalability. The analysis also covers the design aspects of the new draft Version 2 of NTRIP. The latter parts of this thesis report on the experiment results aimed at providing assessment of the current level of implementation of NTRIP. Data latency and integrity using NTRIP over the Internet are examined. Their impacts on users applications as the quality of real-time kinematic positioning is assessed. The results show that the performance of the system satisfies the rigorous requirement of the end-user application. The draft version of the new NTRIP indicates that UDP will be also supported. A similar investigation is carried out, providing the first experiment results on the new option. Tests using similar metrics, data latency and integrity, were carried out to verify the inherent differences between TCP and UDP. It was ascertained that, in most cases, UDP does offer improvement in terms of reduced latency over TCP. However this improvement is not significant enough to affect the performance of users applications tested. Compatibility tests were also carried out and the test results show that the new option experiences some compatibility issues with firewalls and wireless networks.

Diss. University Bern, 2008. / GNSS: Global navigation satellite systems. Literaturverz.

Made available in DSpace on 2014-06-11T19:30:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-20Bitstream added on 2014-06-13T18:40:49Z : No. of bitstreams: 1 aguiar_cr_dr_prud.pdf: 7725475 bytes, checksum: 7556eafce637936e645a266c88f16618 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O efeito da ionosfera é a maior fonte de erro sistemático nos sinais transmitidos pelos satélites do GNSS (Sistema Global de Navegação por Satélite), o qual afeta principalmente a acurácia do posicionamento e navegação pelo GNSS quando se utiliza de receptores de simples frequência. Este erro sistemático é diretamente proporcional ao TEC (Conteúdo Total de Elétrons) presente ao longo do caminho percorrido pelo sinal na ionosfera e inversamente proporcional ao quadrado da frequência deste sinal. Devido à natureza dispersiva da ionosfera, o TEC pode ser determinado a partir das observáveis coletadas com receptores GNSS de dupla frequência, possibilitando o monitoramento e a modelagem da ionosfera. Atualmente, os usuários de receptores de simples frequência podem corrigir o erro sistemático devido à ionosfera utilizando modelos como o de Klobuchar, o NeQuick, os GIMs (Mapas Globais da Ionosfera), entre outros. Neste trabalho é apresentado um método para gerar uma Grade Ionosférica (GI) e seu nível de confiança (GIVE), a fim de melhorar a acurácia em aplicações de posicionamento e navegação pelo GNSS, além de fornecer... / The effect of the ionosphere is the largest error source on the L band signals broadcasted by GNSS (Global Navigation Satellite Systems) satellites, which mainly affects the accuracy of GNSS positioning and navigation when a single frequency receiver is used. The systematic error due to the ionosphere is directly proportional to TEC (Total Electron Content) along the signal path and inversely proportional to the square of the transmitting frequency. Due to the ionosphere’s dispersive nature, TEC can be determined with dual frequency GNSS measurements, allowing the modeling and monitoring of the ionosphere. Currently, users of single frequency receivers can correct the systematic error due to the ionosphere using models such as Klobuchar, the NeQuick the GIMs (Global Ionosphere Maps), and others. This work presents a proposed method to generate an Ionospheric Grid (GI) and Grid Ionospheric Vertical Error (GIVE), which can be used to improve the accuracy ... (Complete abstract click electronic access below)

A caracterização morfométrica e hipsométrica de bacias hidrográficas permite o melhor entendimento do seu funcionamento enquanto sistema, facilita a correlação com suas características e potencializa diversos estudos. O emprego de métodos quantitativos e qualitativos para caracterizar uma bacia hidrográfica possibilita uma maior compreensão da sua dinâmica e por isso o emprego de vários parâmetros é fundamental. Nessa tese é apresentada a análise morfométrica e hipsométrica e a determinação automática de hidrografia e knickpoints na bacia da Lagoa Mirim, uma bacia transfronteiriça, localizada na costa atlântica da América do Sul entre os paralelos 31°S e 34°30’S e entre os meridianos 52°W e 55°30’W, com 58407.78km2 de área, dos quais 47% estão em território brasileiro e 53% em território uruguaio. A análise e obtenção dos parâmetros e a determinação automática de hidrografia e knickpoints na bacia da Lagoa Mirim, foi realizada com técnicas de Geoprocessamento, utilizando as ferramentas de análise espacial e de manipulação de dados do programa ArcGis, versão 10.2.2. Foram utilizadas 15 imagens SRTM (Shuttle Radar Topographic Mission), com resolução espacial de 1 segundo de arco (1”), aproximadamente 30m, para gerar o Modelo Digital de Elevação (MDE) da área de estudo. Este modelo foi validado com levantamento cinemático GNSS (Sistemas Globais de Navegação por Satélite), pós-processado com o método de Posicionamento por Ponto Preciso (PPP). As análises morfométrica e hipsométrica e a determinação da hidrografia e knickpoints da Bacia da Lagoa Mirim foram realizadas a partir do MDE SRTM. A hidrografia foi obtida com o Model Builder e ferramentas hidrológicas do ArcGis. E os knickpoints foram determinados através do Knickpoint Finder, um script em linguagem Python integrado ao ArcTollBox do programa ArcGis. Os resultados demonstram que a utilização de dados SRTM em ambiente SIG (Sistemas de Informação Geográfica) permite a caracterização de bacias hidrográficas, sendo útil para gestão e gerenciamento dos recursos hídricos e para estudos ambientais, mostrando-se uma alternativa prática e viável ao minimizar custos e tempo na execução dos trabalhos. / The morphometric and hypsometric characterization of river basins allows a better understanding of its functioning as a system, facilitates the correlation with its characteristics, and potentiates several studies. The use of quantitative and qualitative methods to characterize a river basin allows a better understanding of its dynamics, therefore the use of several parameters is fundamental. This thesis presents the morphometric and hypsometric analysis and the automatic determination of hydrography and knickpoints in the Mirim Lagoon Basin. Mirim Lagoon basin is a transboundary basin, located in the Atlantic coast of South America, between parallels 31°S and 34°30’S and meridians 52°W and 55°30'W, with an area of 58,407.78 km2, being 47% in Brazilian territory and 53% in Uruguayan territory. The analysis and acquisition of morphometric and hypsometric parameters and the determination of hydrography and knickpoints were performed with geoprocessing techniques, using the spatial analysis and data manipulation tools of the software ArcGIS, 10.2.2 version We used 15 SRTM (Shuttle Radar Topographic Mission) images, version 3, band C, with a spatial resolution of 1 arcsecond (1"), approximately 30 meters, to generate a Digital Elevation Model (DEM) of the study area. This model was validated by means of kinematic GNSS (Global Navigation Satellite System) survey post-processed using the Precise Point Positioning (PPP) method. The intended morphometric and hypsometric analysis and the determination of hydrography and knickpoints of Mirim Lagoon basin were performed using the DEM SRTM. The hydrography was obtained with the Model Builder and the hydrologic tools of ArcGis. And the knickpoints were determined using the Knickpoint Finder, a script in Python language integrated to ArcGis ArcToolbox The results show that the use of SRTM data in GIS (Geographic Information Systems) allows the characterization of the watersheds, which is useful for water resources management and for environmental studies, and prove to be a practical and viable alternative to minimize cost and time in the work execution.

Användandet av maskinstyrning har länge varit vanligt vid större vägbyggen och järnvägsbyggen. Det har likväl blivit allt mer vanligare vid anläggning av vatten- och avloppsledningar [VA-ledningar], dock finns det inte många undersökningar om hur användandet av maskinstyrning påverkar den typen av arbete. Rapporten ska undersöka hur ett VA-projekt blir påverkat av att använda grävmaskiner som är utrustade med maskinstyrning. Undersökningen ska genomföras i två moment, enkätstudie samt en ekonomisk jämförelse, och ska täcka tre olika teman, ekonomi, arbetsmiljö och miljö. Det gjordes olika  enkäter som personer med olika befattningar fick besvara. De som fick enkäter var personer som blev påverkade på olika sätt av att maskinstyrning användes i projekt. Dessa enkäter behandlade alla tre ovan nämnda teman. För att göra en djupare undersökning om hur användandet av maskinstyrning påverkar ekonomin, hämtades siffror på kostnader och framdrift/produktivitet från ett VA-projekt i Toverud, Hammarö. Där användes grävmaskiner som var utrustade med maskinstyrning. Dessa siffror jämfördes mot ett referensprojekt som också utfördes i Hammarö men år 2009 då maskinstyrning inte användes. Resultatet visar att användandet av maskinstyrning ökar produktiviteten samtidigt som det minskar arbetsbelastningen och faror för arbetarna. Eftersom att samma typ av arbete utförs på kortare tid minskar den totala bränsleförbrukningen för projektet. Beräkningarna visade att ett arbete där 1100 meter VA-ledning skulle anläggas gjordes en besparing på 3178 liter diesel samt att utförandetiden gick cirka 15 dagar snabbare om grävmaskinerna var utrustade med maskinstyrning. En begränsning med maskinstyrning är att det uppkommer mycket arbete för mätteknikern om flertalet revideringar av ritningarna krävs. Det är väldigt viktigt att mätteknikern gör ett bra arbete med linjeprofilen, annars försvinner de positiva effekterna med att använda maskinstyrning i arbetet. Höga byggnader och skog kan vara ett problem för mottagningen.  Slutsatsen är att produktiviteten ökar samt att kvalitet på arbetsmiljön blir bättre vid användning av maskinstyrning. / The use of machine control has long been common in major road construction and railway construction. However, machine control has become more and more common when digging trenches for pipe laying, but there are not many studies on how the use of machine control affects a work as trench digging for pipe laying.   The report will investigate how a sewer, water and drain pipe project is influenced by using excavators that are equipped with machine control. The investigation will be conducted in two parts and will cover three different themes, economics, work environment and environment.   Different questionnaires were customized for people with different positions. The persons surveyed were workers affected by the use of machine control in projects. These surveys addressed all three of the above topics.   In order to make a deeper study of how the use of machine control affects the economy, figures on costs and progress / productivity were collected from a trench digging and pipe laying project in Toverud, Hammarö. There they used excavators that were equipped with machine control. These figures were compared to a reference project that was also carried out in Hammarö, but in 2009 when machine control was not used.   The result shows that the use of machine control increases productivity while reducing workload and dangers for workers. Because the same type of work is carried out in less time, the total fuel consumption for the project decreases. The calculations showed that a work involving 1100 meters of trench digging and pipe laying. There would be savings up to around 3178 liters of diesel, and that the execution time would be about 15 days faster if the excavators were equipped with machine control. A limitation of machine control is that there is a lot of work for the surveyor if many revisions of the drawings are required. It is very important that the surveyor performs well with the line profile, otherwise the positive effects of using machine control at work will disappear. High buildings and forests can be a problem for the reception. The conclusion is that productivity increases and quality in the work environment is improved when using machine control.