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Dissertations / Theses on the topic 'GPS surveying'
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Summerfield, Philip John. "Kinematic GPS surveying." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254471.
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Grinker, Barry. "Accuracy of shipborne kinematic GPS surveying." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26341.
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Ffoulkes-Jones, Geraint Huw. "High precision GPS surveying by fiducial techniques." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.258949.
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Khalid, Mohamed A. "Post-processing strategies for precise GPS static surveying." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278740.
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Chen, Wu. "Integration of GPS and INS for precise surveying applications." Thesis, University of Newcastle Upon Tyne, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283586.
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Belhassan, Taher K. "A framework for global positioning system (GPS) surveying technology adoption in the Libyan public surveying sector." Thesis, University of Salford, 2010. http://usir.salford.ac.uk/26575/.
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A global positioning system (GPS) is an innovative type of technology which can be used to increase efficiency and productivity within the surveying discipline and to produce more accurate results. GPS technology is becoming a very popular and effective tool for surveying purposes worldwide. In developing countries like Libya, this technology has not been adequately implemented. This research is aimed at developing a framework in order to improve the use of GPS surveying technology by the Libyan public surveying sector (LPSS). A critical review of the literature formed an initial conceptual framework. Furthermore, a set of factors were identified and presented in the conceptual framework; these factors were human, organizational and technical factors. The research is qualitative in nature, employing a case study approach and using semi-structured interviews as the main data collection tool within the Libyan public surveying sector. Several tools such as documentation and observations were used in order to achieve triangulation. This approach allowed revisions to be made to the theoretical framework derived from the literature by the researcher. A series of in-depth interviews were subsequently conducted with the Libyan Survey Department personnel to validate the factors and refine the conceptual framework in the context of the Libyan public surveying sector. The contribution of the research is to develop a framework to help the Libyan public surveying sector to establish a strategic policy to improve the use of GPS surveying technology in the Libyan public surveying sector (LPSS).
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Joy, Christopher Iain Harold. "GPS assisted helicopter photogrammetry for highway profiling." Thesis, University of Nottingham, 1998. http://eprints.nottingham.ac.uk/11462/.
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Roads are an integral part of today's lifestyle. Indeed, a modern and efficient economy requires a satisfactory road network. The road network in the United Kingdom faces ever-increasing demands with 94% of passenger travel and 92% of freight transport undertaken by road. Maintenance of the network is essential. Prior to the commencement of any maintenance scheme, an accurate highway profile is measured by undertaking a detailed topographic survey of the road surface and the adjacent verges. Traditionally, this is carried out by land surveyors using, for example, a theodolite, EDM and level. Highway surveying by traditional methods is a slow, costly and dangerous process. A photogrammetric technique was devised by Photarc Surveys Ltd of Harrogate, UK to reduce the problems of speed, cost and safety. This helicopter based photographic system can yield topographic data at up to ±5mm rmse through photogrammetric analysis. It is necessary to install ground control points on the hard shoulder for use in the photogrammetric analysis. This research investigates the potential of both conventional aerial triangulation and in-flight GPS assisted aerial triangulation for reducing this ground control requirement. The original photographic system is extended to integrate a GPS positioning system and the performance of this system is assessed through a series of field trials. The results of the research show that the camera can be positioned by the GPS system to within 5 centimetres. The GPS positions can be included in the aerial triangulation to further reduce the requirement for ground control. It is shown that for mapping at the ± 5mm rmse level, there is no potential for height control reduction, even when GPS positions are used. However for mapping at up to ± 20mm, the GPS positions can enable a significant reduction in ground control.
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Roberts, Gethin Wyn. "Real time on-the-fly kinematic GPS." Thesis, University of Nottingham, 1997. http://eprints.nottingham.ac.uk/13395/.
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Considerable interest has been show in the development and application of real time On-The-Fly (OTF) kinematic GPS. A major error source and limitation of such a positioning technique is that caused by cycle slips. When these occur, the integer ambiguities must be resolved for, which can take hundreds of epochs to complete depending on satellite availability and geometry. This research has focused on investigating the applications of real time OTF GPS, as well as its limitations and precision, which has been shown in the thesis to be precise to a few millimetres. The limitations of such a system at present include the use of UHF telemetry links, which at best have a line of sight range of -10 km. The research has shown that alternatives are required, and the use of a relay station can prove invaluable. Cycle slips are another major limiting factor when using OTF GPS, as once a cycle slip occurs, it can either be corrected for or the integer ambiguities resolved for. The second option can take hundreds of seconds, depending on the algorithms used and the satellite number and geometry. This research has partly focused on the development of software which will instantaneously detect and correct for cycle slips in high rate GPS data. The applications of real time OTF GPS are numerous. Research has been carried out to investigate its use to monitor and control construction plant as well as monitoring the movement of large structures. As OTF positioning is precise to a few millimetres, it is ideal for the control of construction plant, and has been compared to laser levelling and precise digital levelling. Such a GPS system gives the user a 3-dimensional position for the bulldozer blade, for example. Such information can prove invaluable for quality control as well as developing an automated system, which would be controlled by real time OTF GPS. In addition, real time OTF GPS has been shown in the research to provide instantaneous positioning of large structures in the form of bridges. Such information could provide future systems which would monitor the structure for dangerous movements, resulting in a failure alarm. Carrier phase kinematic GPS has previously been shown to work over baseline lengths of < 20 km. The use of Multiple Reference Stations (MRS) has been shown in this research to enable OTF GPS to be applied over longer baseline lengths, with a precision in the order of 12 cm over 132 km.
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Gouws, Alison Clare Cochlovius. "Preplanning GPS session lengths for cadastral surveying in South Africa." Thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/26138.
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Combrinck, Willem Ludwig. "Antenna axis offset and intersection determination using GPS." Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/17478.
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Bibliography: p. 101-108.<br>Modern geodesy utilises advanced space techniques such as VLBI to further the study of crustal motion as well as tidal and rotational deformations of the Earth. One of the parameters in the model used to determine the baseline length between VLBI stations, is the antenna axis offset. This offset is the distance between the secondary axis and the normal projection of the secondary axis onto the primary axis. For a non-intersecting axes antenna mounting, this offset is usually several metres in length. The accuracy of the offset value directly influences the total accuracy of the VLBI results. This work describes how GPS is used to determine the offset and VLBI reference point. Several algorithms for calculating these parameters are investigated and evaluated. Methods are developed to minimise the size and influence of errors. An evaluation and comparison of the results to previous independent determinations of the offset, which use different techniques and instrumentation, clearly show the feasibility of using GPS. This method has the added advantage of allowing the VLBI, SLR and GPS reference frames to be co-located.
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Chao, Chih Hung Jason. "Improved modelling of high precision wide area differential GPS." Thesis, University of Nottingham, 1996. http://eprints.nottingham.ac.uk/11522/.
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Wide Area Differential GPS (WADGPS) aims at overcoming the main drawback of conventional DGPS, namely the limited range over which the differential corrections are valid, due to the rapid decorrelation of the error sources with increasing distance from the reference station to the user. In the WADGPS approach, error sources are generated for users over a large portion of the earth, such as a communication satellite's entire footprint, by separating and modelling the main sources of error in GPS measurements. This has the effect of eliminating the limit imposed on the validity of the corrections by the geographical or atmospheric environment. A main advantage of WADGPS is the fact that far fewer reference stations are needed to cover the same area, compared to conventional DGPS. Interest in WADGPS has grown during the last few years, the use of WADGPS both for positioning accuracy requirements and the provision of integrity are being explored. Several research establishments have come up with their own WADGPS methodology and algorithms, all sharing a basic principle, namely the requirement that different error sources which affect GPS navigation are dealt with separately, and their spatial and temporal properties are investigated and modelled individually. Research was carried out to develop an advanced method and the corresponding algorithms, which could provide a high precision WADGPS positioning service. The service would be suitable for single or dual frequency users, and could be introduced with very few reference stations. The two main components of the service are a precise, near real-time orbit determination of the GPS satellites, and an accurate estimation and modelling of ionospheric and tropospheric effects. Results from real data indicate that user position accuracy of the order of 2 m and 3 m (RMS) in plan and height components respectively, were achieved over user-reference distances ranging from 2,000 to 3,500 km.
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Kamarudin, Md Nor. "Local geoid determination from a combination of gravity and GPS data." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363535.
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Wallerström, Mattias, and Fredrik Johnsson. "En nätverks-RTK-jämförelse mellan GPS och GPS/GLONASS." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-130.
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<p>Från den 1 april 2006 har SWEPOS kompletterat den befintliga nätverks-RTK-tjänsten, som dittills levererat RTK-data för GPS, med ett alternativ där RTK-data för GPS/GLONASS levereras. En del användare har rapporterat att de upplever att GPS/GLONASS inte tillför något och även att det ibland kan ta längre tid att få fixlösning. Andra användare hävdar att de nu kan använda nätverks-RTK på platser där de tidigare inte kunde mäta och är mycket positiva till GPS/GLONASS.</p><p>Syftet med detta examensarbete var att undersöka hur tillgängligheten för satellitmätning, positionsnoggrannheten och initialiseringstiden påverkades i öppna respektive störda miljöer med GPS/GLONASS jämfört med enbart GPS vid användandet av nätverks-RTK-tjänsten. Undersökningen har utförts med tre olika fabrikat av GNSS-mottagare (Leica, Topcon och Trimble), vilket även medger att en jämförelse mellan dessa till viss utsträckning kan göras.</p><p>I studien gjordes totalt 1 440 mätningar på sex punkter med kända positioner och med olika grad av sikthinder. Fixlösning uppnåddes inte inom 180 sekunder för 206 (77 för GPS/GLONASS och 129 för GPS) av de 1 440 mätningarna.</p><p>De extra GLONASS-satelliterna tillför en klar fördel när det gäller möjligheten att mäta i störda miljöer. När det gäller initialiseringstid så är dessa kortare för GPS/GLONASS. GLONASS-satelliterna ger ingen förbättring av positionsnoggrannheten. Det är till och med så att GPS får något bättre kvalitetstal i både plan och höjd i denna studie (1-3 mm bättre). För de olika fabrikaten kan det konstateras att precision och noggrannhet är likvärdiga i både plan och höjd för alla tre märken.</p><br><p>On the 1st of April 2006, SWEPOS complemented the existing network RTK service with corrections for the Russian satellite system GLONASS. The service had so far only provided corrections for GPS. Some users have claimed that GPS/GLONASS do not contribute at all and also that the time for initialization sometimes can be longer. However, other users insist on that they now can use network RTK in areas that earlier were impossible and they are very favourable of GPS/GLONASS.</p><p>The purposes of this diploma work were to study and examine measurements using GPS and GPS/GLONASS in areas with different degrees of visual obstacles. Corrections were provided by SWEPOS Network RTK service and availability of satellites, accuracy of position and time for initialization were evaluated. The study has been conducted with three different brands of GNSS receivers (Leica, Topcon and Trimble), which also to some extent makes a comparison between the three brands possible.</p><p>A total number of 1 440 field measurements were made on six well-known points with different degrees of visual obstacles. A fixed solution was not accomplished within 180 seconds for 206 (77 for GPS/GLONASS and 129 for GPS) of the 1 440 measurements.</p><p>The additional GLONASS satellites provide an apparent advantage regarding the possibility to measure in disturbed environments. The time for initialization is shorter for GPS/GLONASS. The GLONASS satellites do not give any improvement in accuracy of position. On the contrary, GPS receives slightly better accuracy numbers in quality for both horizontal and vertical readings (1-3 mm better). Regarding the different brands, it was found that the precision and accuracy were similar in both plane and height for all three brands.</p>
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Gregorius, Thierry Lucien Herve. "GPS, the troposphere and weather fronts : new departments for geophysics and meteorology." Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388652.
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Chekole, Solomon Dargie. "Surveying with GPS, total station and terresterial laser scaner: a comparative study." Thesis, KTH, Geodesi och geoinformatik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145034.
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Mok, Esmond Chi Ming. "A new ambiguity function algorithm for short baseline GPS engineering surveying applications." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318165.
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Bin, Che Amat Muhammad Asyran. "Assessment of long-term deformation in Johor, Malaysia using Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR)." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/47430/.
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Information about deformation in an area has become vital not only for safety assessment but also for maintenance of geodetic infrastructures. The latter is necessary to support accurate surveying and mapping applications. This research exploits the complementary features of Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) techniques to assess the long-term deformation in Johor, Malaysia, which can be induced by natural and/or anthropogenic activities. Furthermore, modelling and mitigation of tropospheric effects in GPS and InSAR are addressed to achieve the best possible precision from the two techniques. Indeed, their modelling and mitigation improve the quality of the estimation as well as provide valuable resources for atmospheric studies. The assessment of long-term deformation in Johor is firstly made by analysing the five years (2007 - 2011) point-specific profile at eight Malaysia Real-Time Kinematic GNSS Network (MyRTKnet) stations. Two processing strategies, namely Precise Point Positioning (PPP) and Double-Difference (DD), are employed to assess their capability for deformation monitoring. The latter also make used of the GPS data from 27 IGb08 stations and 7 International GNSS Service (IGS) stations. Analysis of the results revealed deformation that can be explained by plate tectonic movement and earthquakes in the surrounding region. While results from the PPP processing showed a higher correlation with the recorded earthquakes, the results from DD have improved correlation coefficients at about 4% in the East-West and 5% in the Up-Down components. These improvements are valuable when the rate of deformation is the primary interest. In addition to the point-specific profile, the surrounding deformation of Johor has been assessed with the line-of-sight (LOS) velocity maps from the InSAR time-series. Two sets of ERS-1/2 data, consisting a total of 67 images acquired at two descending tracks (i.e. track 75 and 347), are utilised for the generation of the maps. Moreover, the feasibility of Sentinel-1 satellites is also tested, which revealed improved coherence owing to their short revisit cycle. Some part of Johor showed subsidence and uplift trends, which also agreed with the literature. This information cannot be perceived by the GPS alone due to its limited coverage; hence, further attests to the benefit of their joint analysis. Numerous developments have been implemented in the in-house software (i.e. Punnet) such as the implementation of tropospheric correction, outlier’s rejection scheme, statistical analysis to identify the control point for phase unwrapping, and a new method to retrieve temporal evolution of deformation for a rapidly deforming area.
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Flor, Andrew Douglas. "Evaluating Levee Failure Susceptibility on the Mississippi River Using Logistic Regression Analysis and GPS Surveying." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1791850971&sid=8&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Johansson, Daniel, and Sören Persson. "Kommunikationsalternativ för nätverks-RTK : - virtuell referensstation kontra nätverksmeddelande." Thesis, Högskolan i Gävle, Institutionen för teknik och byggd miljö, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-3769.
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Vid användning av nätverks-RTK behöver driftcentralen kommunicera med användarens GNSS-mottagare på ett effektivt sätt oberoende av fabrikat. Av den anledningen finns ett standardiserat format för överföring av data som är utvecklat av RTCM (The Radio Technical Commission for Maritime Services). 2006 publicerades version 3.1 som stödjer utsändning av s.k. nätverksmeddelande som innebär att komprimerade observationsdata skickas till mottagaren för beräkning av korrektioner. För att bestämma GNSS-mottagarens position används i dagsläget till största delen VRS-tekniken (Virtual Reference Station). Denna teknik används bland annat av SWEPOS som driver en nätverks-RTK-tjänst i Sverige. VRS-tekniken kräver att mottagarens position ska skickas till driftcentralen, där huvuddelen av beräkningarna sker. Nätverksmeddelande har inte funnits i tidigare versioner av RTCM-standarden, men införandet av dem innebär bland annat att korrektioner kan skickas med envägskommunikation och att större delen av beräkningarna kan göras i mottagaren. Syftet med studien är att göra jämförelser mellan VRS och RTCM 3.1 nätverksmeddelande, med avseende på bland annat mätkvalitet och initialiseringstider. I studien ingick även att undersöka behovet av nätverksmeddelande och hur tekniken fungerar under förflyttning. I studien användes GNSS-mottagare från Leica och Trimble för att göra upprepade mätningar med dels VRS och dels RTCM 3.1 nätverksmeddelande med s.k. automatisk respektive statisk konfiguration. Statisk konfiguration användes i två olika nät, ett där SWEPOS-stationen Gävle och ett där SWEPOS-stationen Leksand användes som s.k. masterstation. Totalt 1200 mätningar utfördes på tre väl inmätta punkter under 12 dagar. Vid varje mätning registrerades tiden till fixlösning och mätt position. Resultaten bearbetades därefter och analyserades med statistiska metoder. Resultaten visade bland annat att initialiseringstiden för nätverksmeddelande är något längre än för VRS och att det inte finns någon större skillnad i kvalitetstalen mellan VRS och nätverksmeddelande. Inte heller mellan det automatiska nätet och de statiska näten finns någon större skillnad. 95:e percentilens avvikelser var i plan 25 mm och i höjd 45 mm. De enda resultaten som skiljde sig nämnvärt från övriga var mätningarna med Leica i det statiska nätet med Leksand som masterstation, där Leica hade problem med att få fixlösning.<br>When using network RTK the control centre needs to communicate with the user's GNSS receivers in an efficient manner regardless of the brand of equipment. For this reason, a standardized format for transmission of data has been developed by RTCM (the Radio Technical Commission for Maritime Services). In 2006 the version 3.1 was released which supports broadcasting of network RTK messages which means that the compressed observation data are sent to the rover for calculation of corrections. Today the most used concept to determine the position of the rover is VRS (Virtual Reference Station). SWEPOS, which provides a network RTK service in Sweden, is based on the VRS concept. The concept requires that the position of the rover should be sent to the control centre, where most of the calculations are made. Network RTK messages have not been found in earlier versions of the RTCM standard, but their introduction means that corrections can be sent with one-way communication and that most of the calculations can be made in the rover. The purpose of the study is to make comparisons between the VRS and RTCM 3.1 network RTK messages regarding the measurement quality and the time for initialization. The study also included to examine the need for network RTK messages and how the technology works while continuously moving the rover. The study used GNSS receivers from Leica and Trimble to make repeated measurements with VRS and with RTCM 3.1 with automatic and static configurations. Static configuration was used in two different networks, one in which the SWEPOS station Gävle and one in which the SWEPOS station Leksand was used as master station. Totally 1200 measurements were carried out on three known points in 12 days. At each measurement the time for initialization and the measured position was registered. The results were then processed and analysed using statistical methods. The results showed that the times for initialization regarding network RTK messages are slightly longer than for VRS and that there is no obvious difference in quality between the VRS and network RTK messages. The difference between the automatic network and the static network is not noticeable either. 95th percentile discrepancies were 25 mm horizontally and 45 mm vertically. The only results that clearly differed from the rest of the measurements were those with Leica in the static network with Leksand as master station, where Leica had problems to resolve the ambiguities.
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Nayati, Mohammed Abdul Khader. "School bus routing and scheduling using GIS." Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-547.
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<p>School bus routing and scheduling are among the major problems because school bus transportation needs to be safe, reliable and efficient. Hence, the research question for this thesis is to answer how to transport students in the safest, most economical and convenient manner. The objective of this thesis is to create a GIS based school transport management system which helps in bus-stop allocation, design fastest and safest bus routes with AVL facility. This thesis also aims to investigate how a school transportation management system may improve the transportation security. The result from this study has helped to develop a school bus routing and scheduling prototype model for Sujatha High School, Hyderabad. This prototype model will help the school transportation management to design shortest and fastest school bus routes and they can also allocate bus stops, which will help them in selecting the pick-up stops for the students and staff, according to their concentration in the areas. This thesis has also, through literature study, investigated how a school transport management system can improve the transportation security. For the time being, there is a general belief that ICT contributes to improving the security, although a quantification of such improvements are lacking. The user interface application has been developed by using VBA and ArcGIS 9.1 Network Analyst provided by Environmental Science Research Institute and it has been evaluated by GIS users.</p>
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Genel, Kerim, and Jörgen Andersson. "3D-visualization of fairway margins, vessel hull versus depth data." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-232.
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<p>Fledermaus is software where different kind of analysis with spatial data can be done. The main area where to use Fledermaus is related to hydrographical surveys. This study is aimed to test and analyse the way Swedish Maritime Administration (Sjöfartsverket) uses Fledermaus. Through step by step explaining how to do when measuring sea bed conditions from a vessel, this text is possible to use as a manual for the applications that are mentioned in this report.</p><p>Another thing that is treated is the squat effect that belongs to vessel dynamic motions. Test of visualization that concerning squat in Fledermaus is done, but with a negative result when squat in a perspective to show motions in height that can be up to about a metre is very hard in a terrain model of thousands of metres. By further tests by arranging the input data, several interesting diagrams have been created through Microsoft Excel where graphs show that the depths are affecting the squat effect. This is showed in same diagram but with two different scales to show the relationship between how a point at the vessel moves in height compared to the depth under the vessel when the vessel is navigating in the sea.</p><br><p>Fledermaus är en programvara där olika analyser med rumsliga data kan genomföras. Största användningsområdet är att använda Fledermaus till mätningar som är relaterade till sjömätning. Den här studien är inriktad till att testa och analysera applikationer som Sjöfartsverket använder sig av i Fledermaus. Genom att steg för steg förklara hur Fledermaus ska användas när bottenförhållanden ska mätas sett från ett fartyg, så blir texten även möjlig att använda som en manual till de applikationer i Fledermaus som är nämnda i denna rapport.</p><p>Det andra som behandlas är squateffekten som tillhör ett fartygs dynamiska rörelser. Test av visualisering som behandlar squat i Fledermaus är genomförd, dock med negativt resultat då squat i ett perspektiv med att visa rörelser i höjd som kan uppgå till runt en meter är väldigt svårt i en terrängmodell som sträcker sig tusentals meter. Dock genom vidare tester genom behandling av indata, har flertalet intressanta diagram skapats genom Microsoft Excel där kurvor visar att djupet inverkar på squateffekten. Detta visas genom att i samma diagram fast med två olika skalor visa förhållandet mellan hur en punkt på båten rör sig i höjd jämfört med att djupet under fartyget ändras då fartyget gör fart genom vattnet.</p>
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Ingelman-Sundberg, Simon, and Salem Ali Mishal. "Transformation av stomnät till SWEREF 99 : Fallstudie Norra Vätö, Norrtälje kommun." Thesis, Högskolan Väst, Institutionen för ingenjörsvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-2739.
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Sverige har under lång tid haft flera olika koordinatsystem, både nationella och lokala. Nu genomförs en övergång till ett gemensamt koordinatsystem som kallas SWEREF 99. I Norrtälje kommun finns stomnät som är noterade i ett flertal olika koordinatsystem, med ursprung i tidigare förrättningar. Åtskilliga av dessa har dålig orientering i kända nationella koordinatsystem men däremot god inre noggrannhet. I detta arbete väljs 12 stomnät för transformation till SWEREF 99 18 00. Detta görs genom att passpunkter mäts in med GNSS-teknik. De inmätta punkterna används sedan för att transformera stomnäten som de är noterade i. Detta gör att i framtiden kan till exempel husutsättningar i de aktuella områdena utföras med enbart GNSS-teknik. Stomnäten som väljs finns på norra delen av ön Vätö i Norrtälje kommun. GNSS-utrustningen som används för att mäta in punkterna är Leica 1203 nätverks-RTK. De valda passpunkterna mäts in vid två tillfällen med minst 45 minuters mellanrum. Vid varje tillfälle görs 10 mätningar. Sedan beräknas medelvärdet av 20 mätningar. När alla punkter väl har mätts in görs transformationer från tre olika från-system till SWEREF 99 18 00. De tre från-systemen är RT 38 2,5 gon V, RT R09 0 gon och ett lokalt 1000/1000-system. Eftersom områdena som är noterade i RT 38 är dåligt orienterade gentemot varandra ger det dålig noggrannhet att transformera hela RT 38-området på en gång. Därför delas RT 38-området in i flera transformationsområden. När transformationen gjorts kontrollmäts fastighetsgränser i ett gränsområde där gränspunkternas koordinatsystem är osäkert. Avslutningsvis kontrollmäts en Rix 95-punkt med namnet Klockarängsberget (Rix 95-punktnummer: 119741) som finns på södra delen av Vätö.<br>During the last century different coordination systems have been used in Sweden. Today a common coordination system (SWEREF 99) is used. In the municipality of Norrtälje, core networks are listed in different coordination systems that are generated from different earlier missions. These networks normally have poor orientation in the known coordination system; however, the internal accuracy is used to be good. In this study, some of the core networks have been selected to be converted to SWEREF 99 18 00. The conversion has been done by measuring points using the GNSS technology, the measured points were then used to transfer the core network to SWEREF 99 18 00. This means that in the future, staking out a building in the area can be performed solely by GNSS technology. The chosen core networks are located on a part of the island Vätö in the municipality of Norrtälje. The GNSS equipment used to measure the points with was the Leica 1203 RTK network. The selected points were measured on two occasions with a gap between the occasions of at least 45 minutes. Ten repeated measurements have been done on each point to increase the accuracy. The average of these twenty measurements has been used for conversion. After the measuring process, the transformation has been done from three different off-systems to SWEREF 99 18 00. The three off-systems were RT 38 2.5 gon V, RT R09 0 gon and a local 1000/1000-system. Since the areas listed in the RT 38 were poorly oriented towards each others, poor accuracy was achieved during the transformation of the entire RT 38 field at once. Therefore, the RT 38 area has been divided into a number of transformations-areas. When the transformation had been done, control measurements were made on a Rix 95-Point entitled Klockarängsberget (Rix 95-point numbers: 119 741) located on the southern part of Vätö. In addition, control measurements were made of housing estate border area, where the border points were uncertain.
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Andersson, Johan Vium. "A Complete Model for Displacement Monitoring Based on Undifferenced GPS Observations." Doctoral thesis, Stockholm : Division of Geodesy, Royal Institute of Technology (KTH), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4794.
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Taboga, Alessia. "The development of integrated high-resolution geophysical, photogrammetric and GPS surveying applied to landslides in the South Wales coalfield." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/54058/.
Full textAbstract:
The aim of this research is to develop an integrated and cost-effective site investigation approach for slow moving landslides or potentially unstable slopes found within the South Wales Coalfield, an area of complex geology and hydrogeology. The research was based on the use and assessment of a wide range of surface geophysical techniques, supported by GPS and Digital Photogrammetry surveying, and the joint interpretation of the results which such techniques provide. The South Wales Coalfield has one of the highest concentrations of urban landslides in the UK due to its layered Carboniferous geology. Quaternary / Holocene geomorphology, coal mining history and relatively high rainfall. Mynydd yr Eglwys landslide (Ystrad, Rhondda Cynon Taff) was selected as the field study site because it can be considered representative of the active landslides found within the area. In autumn 1998, following an exceptional heavy rainfall period, a new compound deep- seated failure developed in a previously mined hillslope. This deep-seated failure then caused the reactivation of ancient periglacial debris slides downslope creating a serious risk to the modern housing estate located close to the toe. Electromagnetic (GEM-2), self potential, electrical resistivity tomography, seismic refraction tomography, MASW and induced polarization geophysical data were all acquired on the landslide. This combination of techniques provided information on lithology, faulting, degree of rock fracturing/weathering, thickness of displaced material, spatial distribution of areas with high water/clay content and the direction of groundwater flow. The repetition of a few ERT and SP profiles showed the applicability of geophysical monitoring in detecting changes in groundwater content and defining preferential groundwater pathways within the hillslope. Digital Photogrammetry from Helium balloon can provide a 3D landslide topographic model with 10cm-level accuracy. Topcon HiPer Pro GPS+ instrument can be used in RTK mode to monitor movement with 12mm and 15mm horizontal and vertical precision respectively.
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Vargas, Rosane Maciel de Araújo. "Análise da aplicação do Sistema de Posicionamento Global (GPS) em levantamento topográfico de vias urbanas." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-13062017-092045/.
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Os levantamentos topográficos para implantação de vias urbanas são usualmente realizados utilizando instrumentos e processos clássicos da topografia. A presença de obstáculos (casas, prédios) ao longo do percurso, reduz a produtividade do trabalho além de contribuir para a imprecisão dos resultados. Este trabalho analisa a metodologia de utilização de receptores do sistema GPS (Global Positioning System) para o georeferenciamento, implantação de bases de apoio e complementação ao levantamento convencional com Estação Total. No desenvolvimento do projeto de uma via, é de esperar que desvios centimétricos na determinação das coordenadas dos pontos das bases de referência pouco afetam os resultados finais. Procurando verificar a contribuição destes desvios, foram realizados vários levantamentos convencionais e com o GPS ao longo do eixo de uma via projetada na cidade de São Carlos. No final do trabalho são analisados aspectos referentes a execução destes levantamentos, concluindo sobre as vantagens e desvantagens de cada método e da integração GPS e Estação Total.<br>The surveying for development of urban roads are usually accomplished by using instruments and processes of classic Topography. The presence of obstacles (houses, buildings) along the course it reduces the productivity of the work besides contributing for the imprecision of the results. This work analyzes the methodology of use of receivers of the GPS (Global Positioning System) for georeferring, implant of support bases and complementation to the surveying with Total Station. In the development of the project of a road, it is expected that centimetric deviations in the determination of the points coordinates of the reference bases cause small effects in the final results. Trying to verify the contribution of these deviations, several surveys were accomplished with the Total Station and GPS along the axis of a road projected in the city of São Carlos. In the end of the work several aspects are analyzed about the execution of these surveys, concluding on the advantages and disadvantages of each method and of the integration GPS and Total Station.
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Forward, Troy Andrew. "Quasi-Continuous GPS Steep Slope Monitoring: A Multi-Antenna Array Approach." Curtin University of Technology, Department of Spatial Sciences, 2002. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=11914.
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This thesis investigates the design, implementation and validation of a multi-antenna GPS system to monitor the displacement of deforming slopes. The system utilises a switched antenna array design allowing data from multiple antennas to be sampled sequentially by one GPS receiver. The system provides quasi-continuous GPS observations that can produce a precise and reliable coordinate time-series of the movement of the slope under consideration. GPS observations and particularly those concerned with the monitoring of steep slopes, are subject to systematic errors that can significantly degrade the quality of the processed position solutions. As such, this research characterises the data in terms of multipath effects, the spectrum of the coordinate time-series, and the carrier to noise power density ratio of the raw GPS observations. Various GPS processing parameters are then investigated to determine optimal processing parameters to improve the precision of the resulting coordinate time-series. Results from data stacking techniques that rely on the daily correlation of the repeating multipath signature find that the GPS data actually decorrelates somewhat from day to day. This can reduce the effectiveness of stacking techniques for the high precision monitoring of steep slopes. Finally, advanced stochastic models such as elevation angle and carrier-to-noise weighting are investigated to optimise the precision of the coordinate time-series data. A new in-line stochastic model is developed based on weighting GPS observations with respect to the level of systematic error present within the data. By using these advanced types of stochastic models, reductions to the noise level of the coordinate time-series of approximately 20 and 25 percent are possible in the horizontal and height components respectively.<br>Results from an extensive field trial of this system on a deforming high-wall of an open-pit mine indicate that approximately 135mm of displacement occurred over the 16-week field trial. The precision of the coordinate time-series for surface stations approaches ±4.Omm and ±5.4mm in the horizontal and height components respectively. For sub-surface stations next to the mine wall, coordinate precision has been determined as ±4.9mm.component and ±7.6mm in the height component respectively.
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Walid, Hanna Motaz. "Aanvändning av lantmäteriets nya nationella höjdmodell (laserdata) i skogsmark." Thesis, Högskolan Väst, Avdelningen för data-, elektro- och lantmäteriteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-10352.
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Detta arbete redogör för hur användning av den nya nationella höjdmodellen (NNH) ur/i Lantmäteriet databas kan användas i olika terräng och vilka förutsättningar det finns för identifiering av specifika landskapselement i denna, manuellt och visuellt. Sedan 2009 har Lantmäteriet laserskannat hela landet, både på land och över vatten. Uppdraget är slutfört 2015. Målet med laserskanning är att framställa en rikstäckande höjdmodell med ett medelfel som är bättre än 0.5 m. Idag är all NNH-data tillgänglig som LAS-filer på Lantmäteriets databas. För att kunna utföra ett utvärderingsexperiment valdes ett geografiskt begränsat område: I Skepplanda, Ale kommun i Västra Götalands län. De hjälpmedel som användes var GPS-mottagare, LAS-filer, Ortofoto och applikationsprogram såsom OL-laser och ArcGis. Det främsta syftet med studien var att undersöka hur bearbetning och utvärdering av olika kartmaterial kan utföras, för att sedan kunna bedöma i vilken mån användning av Lantmäteriets NNH-data, i olika typer av terräng, kan vara möjlig t.ex. hur små detaljer kan urskiljas i det. För undersökningen valdes specifika objekt, såsom stenmurar och ett dike. Tre olika kartunderlag framtogs av OL-laserprogrammet: lutningsbilder, intensitetsbilder och terrängskuggningsbilder. Utifrån insamling av inmätta punkter och med hjälp av vektordata kunde materialet utvärderas visuellt. Två kartor valdes, vilka uppfyllde kriterierna för att kunna uppnå studiens syfte. Eftersom kartan med terrängskuggning och lutningsbild ger en tydligare profil av områdets karaktäristiska drag på marknivå, är det möjligt att identifiera små markdetaljer såsom stenmurar och diken. Resultatet varierade från fall till fall, beroende på kartunderlaget. En mur på den ena platsen i en bild kunde t.ex. detekteras, men inte i en annan bild, trots att det finns en mur där. Studien visade att laserpulserna har svårt att tränga igenom tät vegetation, dock kan olika solvinklar och belysningsriktningar ändå framhäva vissa små markdetaljer under en tätskog. Andra faktorer som kan ha påverkat kvalitén på lasermaterialet är flyghöjden, laserskannerns vinkel och under vilken period under året skanningen genomfördes. Ett antagande gjordes, att laserskanning från lägre flyghöjd och mindre öppningsvinkel kan höja kvalitén på laserdata. Med dessa två faktorer kan högre upplösning per kvadratmeter yta uppnås. Ett annat sätt som kan vara aktuellt i en undersökning är att använda OL-laser verktygslåda och tillämpa andra inställningar genom att skapa objekthöjdbilder där höjd färgläggs med olika ekvidansnivå. Genom att prova fram olika inställningar i programmet, där olika lutningshöjd och solvinklar tillämpas kan läsbarheten på kartunderlaget förbättras.<br>This work describes how the use of the new national elevation model (NNH) from the National Land Survey database may be used in a variety of terrain and the conditions they are identification of specific landscape elements, manually and visually. From the start of 2009, the national land Survey laserscannat whole country, both on land and over water. The mission will be completed in 2015. The goal of laser scanning is to produce a nationwide elevation model with a standard error of better than 0.5 m for a 2 m GRID. Today, all NNH data available as LAS files on Lantmäteriet's database. To perform an evaluation experiment was elected a geographically limited area: Skepplanda, Ale Municipality in Västra Götaland. The devices used were GPS receiver, LAS files, Orth imagery and application programs such as OL laser and ArcGIS. The main aim of the study was to investigate the processing and evaluation of different map material can be performed, and then to assess to what extent the use of Lantmäteriets NNH- data in different types of terrain may be possible. For the investigation, the specific items, such as stone walls and a ditch. Three different maps material was developed by the OL laser program: slope images, intensity images and terrain shading images. Based on the collection of measured points and using vector data could material evaluated visually. Two maps were chosen, which met the criteria for being able to achieve the objectives of the study. Since the map with terrain shading and gradient image provides a clearer profile of the area's characteristic features at ground level, it is possible to identify small land features such as stone walls and ditches. Results will vary from case to case, depending on the substrate maps. A wall at one location in an image could e.g. detect, but not in another image, even though it's a wall there. That’s why definitive conclusions could be not established. The study showed that the laser pulses are difficult to penetrate dense vegetation; however different solar angles and lighting directions nonetheless highlight some small land details during a dense forest. Other factor that may have affected the quality of the laser material is the altitude, laser scans angle and during which period of the year the scan was performed. An assumption was made that the laser scans from lower altitude and smaller opening angle can add value to laser data. With these two factors, higher resolution per square meter of surface is achieved. Another way that can be relevant in an investigation is to use the OL laser toolbox and apply different settings to create objects height pictures where height is colored with different evidence level. By trying out different settings in the program, where different slope height and solar angles applied to the readability of the chart surface is improved.
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Blumenbach, Thomas. "GPS-Anwendungen in der Sportwissenschaft - Entwicklung eines Messverfahrens für das Skispringen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1125476938399-98504.
Full textAbstract:
Die zentimetergenaue satellitengestützte Positionierung hat in den letzten Jahren immer größere Verbreitung in den verschiedensten Bereichen gefunden. In der Literatur wird von ersten Anwendungen auch in der Sportwissenschaft berichtet. Für höchste Genauigkeitsanforderungen werden geodätische GPS-Empfänger und Antennen eingesetzt, deren Anbringung an Athleten aufgrund ihrer Masse und ihres Volumens jedoch problematisch erscheinen.Ausgehend von den Möglichkeiten, die miniaturisierte Elektronik heute bietet, wurde für die Anwendung im Skispringen ein spezieller GPS-Empfänger entwickelt, der komplett in einen Sprunghelm integriert werden konnte. Damit entstehen nur minimale Beeinträchtigungen im Training. Der untersuchte Athlet benutzt anstatt seines eigenen Helms den Messhelm. Die topographische Lage der Schanzen bewirkt größere Abschattungen der Satellitensignale, sodass GPS-Messungen nicht auf jeder Schanze und zu jeder Tageszeit möglich sind. Die Anzahl gleichzeitig beobachtbarer Satelliten ist vergleichsweise gering. Zentimetergenaue Positionen können zudem nur nach erfolgreicher Mehrdeutigkeitsfestsetzung erzeugt werden. Gängige GPS-Berechnungsalgorithmen gehen dabei unter anderem von der Voraussetzung ausreichend langer und unterbrechungsfreier Messungen aus, die mit der nutzbaren Zeitspanne von 10-20 Sekunden für Anlauf, Absprung, Flug und Landung jedoch nicht erfüllt werden kann. Deshalb wurde ein laserbasiertes Lichtschrankensystem entwickelt, mit dem Passpunktinformationen für den GPSHelm beim Absprung vom Schanzentisch erzeugt werden können. Diese Informationen fließen in die GPS-Trägerphasenauswertung ein und sorgen für eine hohe Genauigkeit und Zuverlässigkeit der Mehrdeutigkeitsfestsetzung. Der gesamte Sprung kann so zentimetergenau bestimmt werden. Im Rahmen von Trainingslehrgängen wurden Messungen gemeinsam mit kinemetrischen und dynamometrischen Untersuchungen durchgeführt und erfolgreich ausgewertet. Anhand dieser Ergebnisse wurde dargelegt, welche vielfältigen Informationen in Geschwindigkeits- und Ortskurven für Anlauf-, Absprung- und Flugphase enthalten sind<br>Carrier phase based GPS applications with centimeter accuracy have become more popular over the last years, not only in surveying. First investigations are accomplished in sports sciences as well. However, most geodetic GPS equipment is too large and too heavy for attaching it at the athletes body. Using the potential of miniaturized electronics, a special GPS receiver for ski jumping was developed. The hardware could be integrated completely into a common jumping helmet. Striving to an ideal measurement system with no influence on the athlete activities only little adverse effects remain on the athletes using the GPS-helmet. The topography of jumping hills results in a more or less shadowing of the GPS satellite signals. Not all jumping hills are applicable for GPS measurements. Measurement campaigns need to be well planned considering satellite constellation issues. Centimeter accuracy requires successful integer ambiguity fixing. Common algorithms assume uninterrupted signal reception over a sufficient long time. But the 10 ?20 seconds for an attempt, take-off, flight and landing are not long enough. Thus a laser light barrier array was developed. It determines position and time of the GPS-helmet during athletes take-off from the ramp. This information enables the ambiguity fixing and enhances accuracy and reliability of the solution, even for short GPS measurement segments. The system was successfully tested during some training sessions of german ski jumpers. It was shown which informations can be derived from positions and velocities for several phases of a jump
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Blumenbach, Thomas. "GPS-Anwendungen in der Sportwissenschaft - Entwicklung eines Messverfahrens für das Skispringen." Doctoral thesis, Technische Universität Dresden, 2004. https://tud.qucosa.de/id/qucosa%3A24557.
Full textAbstract:
Die zentimetergenaue satellitengestützte Positionierung hat in den letzten Jahren immer größere Verbreitung in den verschiedensten Bereichen gefunden. In der Literatur wird von ersten Anwendungen auch in der Sportwissenschaft berichtet. Für höchste Genauigkeitsanforderungen werden geodätische GPS-Empfänger und Antennen eingesetzt, deren Anbringung an Athleten aufgrund ihrer Masse und ihres Volumens jedoch problematisch erscheinen.Ausgehend von den Möglichkeiten, die miniaturisierte Elektronik heute bietet, wurde für die Anwendung im Skispringen ein spezieller GPS-Empfänger entwickelt, der komplett in einen Sprunghelm integriert werden konnte. Damit entstehen nur minimale Beeinträchtigungen im Training. Der untersuchte Athlet benutzt anstatt seines eigenen Helms den Messhelm. Die topographische Lage der Schanzen bewirkt größere Abschattungen der Satellitensignale, sodass GPS-Messungen nicht auf jeder Schanze und zu jeder Tageszeit möglich sind. Die Anzahl gleichzeitig beobachtbarer Satelliten ist vergleichsweise gering. Zentimetergenaue Positionen können zudem nur nach erfolgreicher Mehrdeutigkeitsfestsetzung erzeugt werden. Gängige GPS-Berechnungsalgorithmen gehen dabei unter anderem von der Voraussetzung ausreichend langer und unterbrechungsfreier Messungen aus, die mit der nutzbaren Zeitspanne von 10-20 Sekunden für Anlauf, Absprung, Flug und Landung jedoch nicht erfüllt werden kann. Deshalb wurde ein laserbasiertes Lichtschrankensystem entwickelt, mit dem Passpunktinformationen für den GPSHelm beim Absprung vom Schanzentisch erzeugt werden können. Diese Informationen fließen in die GPS-Trägerphasenauswertung ein und sorgen für eine hohe Genauigkeit und Zuverlässigkeit der Mehrdeutigkeitsfestsetzung. Der gesamte Sprung kann so zentimetergenau bestimmt werden. Im Rahmen von Trainingslehrgängen wurden Messungen gemeinsam mit kinemetrischen und dynamometrischen Untersuchungen durchgeführt und erfolgreich ausgewertet. Anhand dieser Ergebnisse wurde dargelegt, welche vielfältigen Informationen in Geschwindigkeits- und Ortskurven für Anlauf-, Absprung- und Flugphase enthalten sind.<br>Carrier phase based GPS applications with centimeter accuracy have become more popular over the last years, not only in surveying. First investigations are accomplished in sports sciences as well. However, most geodetic GPS equipment is too large and too heavy for attaching it at the athletes body. Using the potential of miniaturized electronics, a special GPS receiver for ski jumping was developed. The hardware could be integrated completely into a common jumping helmet. Striving to an ideal measurement system with no influence on the athlete activities only little adverse effects remain on the athletes using the GPS-helmet. The topography of jumping hills results in a more or less shadowing of the GPS satellite signals. Not all jumping hills are applicable for GPS measurements. Measurement campaigns need to be well planned considering satellite constellation issues. Centimeter accuracy requires successful integer ambiguity fixing. Common algorithms assume uninterrupted signal reception over a sufficient long time. But the 10 ?20 seconds for an attempt, take-off, flight and landing are not long enough. Thus a laser light barrier array was developed. It determines position and time of the GPS-helmet during athletes take-off from the ramp. This information enables the ambiguity fixing and enhances accuracy and reliability of the solution, even for short GPS measurement segments. The system was successfully tested during some training sessions of german ski jumpers. It was shown which informations can be derived from positions and velocities for several phases of a jump.
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Štrba, Peter. "Určení přetvoření železničního svršku." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226760.
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The aim of this diploma thesis is to specify the displacement and deformations of the railway tracks axis on bridge structures in cities of Zábřeh na Moravě and Břeclav. The bridge structures covered have great dilatation distances, therefore it is necessary to monitor the movements of the railway tracks depending on climatic conditions. GPS methods have been used throughout the whole measurement and data processing. The result includes also a comparison of GPS and conventional methods. The result of the thesis is a detection of proven displacements. One of the goals of the thesis is the comparison of the displacements and the accuracy using the method chosen by author of the thesis and using classical geodetic methods.
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Tabatabaei, Balaei Asghar Surveying & Spatial Information Systems Faculty of Engineering UNSW. "Detection, characterization and mitigation of interference in receivers for global navigation satellite systems." Publisher:University of New South Wales. Surveying & Spatial Information Systems, 2007. http://handle.unsw.edu.au/1959.4/40545.
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GPS has become very popular in recent years. It is used in wide range of applications including aircraft navigation, search and rescue, space borne attitude and position determination and cellular network synchronization. Each application places demands on GPS for various levels of accuracy, integrity, system availability and continuity of service. Radio frequency interference (RFI) which results from many sources such as TV/FM harmonics, radar or mobile satellite systems, presents a challenge to the use of GPS. It can affect all the service performance indices mentioned above. To improve the accuracy of GPS positioning, a continuously operating reference station (CORS) network can be used. A CORS network provides all the enabled GPS users in an area with corrections to the fundamental measurements, producing more precise positioning. A threat to these networks is a threat to all high-accuracy GPS users. It is therefore necessary to monitor the quality of the received signal with the objective of promptly detecting the presence of RFI and providing a timely warning of the degradation of system accuracy, thereby boosting the integrity of GPS. This research was focused on four main tasks: a) Detection. The focus here is on a power spectral density fluctuation detection technique, in which statistical inference is used to detect narrowband continuous-wave (CW) interference in the GPS signal band after being captured by the RF front-end. An optimal detector algorithm is proposed. At this optimal point, for a fixed Detection Threshold (DT), probability of false alarm becomes minimal and for a fixed probability of false alarm, we can achieve the minimum value for the detection threshold. Experiments show that at this point we have the minimum computational load. This theoretical result is supported by real experiments. Finally this algorithm is employed to detect a real GPS interference signal generated by a TV transmitter in Sydney. b) Characterization. In the characterization section, using the GNSS signal structure and the baseband signal processing inside the GNSS receiver, a closed formula is derived for the received signal quality in terms of effective carrier to noise ratio ( ). This formula is tested and proved by calculating the C/No using the I and Q data from a software GPS receiver. For pulsed CW, a similar analysis is done to characterize the effect of parameters such as pulse repetition period (PRP) and also duty cycle on the received signal quality. Considering this characterization and the commonality between the GPS C/A code and Galileo signal as a basis to build up a common term for satellite availability, the probability of satellite availability in the presence of CW interference is defined and for the two currently available satellite navigation systems (GPS L1 signal and Galileo signal (GIOVE-A BOC(1, 1) in the E1/L1 band)) it is shown that they can be considered as alternatives to each other in the presence of different RFI frequencies as their availability in the presence of CW RFI is different in terms of RFI frequency. c) Mitigation. The last section of the research presents a new concept of ?Satellite Exclusion Zone?. In this technique, using our previously developed characterization techniques, and considering the fact that RFI has different effects on different satellite signals at different times depending on satellite Doppler frequency, the idea of excluding the most vulnerable satellite signal from positioning calculations is proposed. Using real data and real interference, the effectiveness of this technique is proven and its performance analyzed. d) Hardware implementation. The above detection technique is implemented using the UNSW FPGA receiver board called NAMURU.
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Hussain, Tayyab. "Checking the integrity of Global Positioning Recommended Minimum (GPRMC) sentences using Artificial Neural Network (ANN)." Thesis, University of Gävle, Ämnesavdelningen för samhällsbyggnad, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-5205.
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<p>In this study, Artificial Neural Network (ANN) is used to check the integrity of the Global Positioning Recommended Minimum (GPRMC) sentences. The GPRMC sentences are the most common sentences transmitted by the Global Positioning System (GPS) devices. This sentence contains nearly every thing a GPS application needs. The data integrity is compared on the basis of the classification accuracy and the minimum error obtained using the ANN. The ANN requires data to be presented in a certain format supported by the learning process of the network. Therefore a certain amount of data processing is needed before training patterns are presented to the network. The data pre processing is done by the design and development of different algorithms in C# using Visual Studio.Net 2003. This study uses the BackPropagation (BP) feed forward multilayer ANN algorithm with the learning rate and the momentum as its parameters. The results are analyzed based on different ANN architectures, classification accuracy, Sum of Square Error (SSE), variables sensitivity analysis and training graph. The best obtained ANN architecture shows a good performance with the selection classification of 96.79 % and the selection sum of square error 0.2022. This study uses the ANN tool Trajan 6.0 Demonstrator.</p>
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Törnqvist, Jonas. "En osäkerhetsundersökning av GNSS-mottagare." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-56723.
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Today, GNSS measurements play an important role in the surveying industry, and their use is ever increasing. Many different GNSS receivers and antenna manufacturers are on the market with new ones appearing. The purpose of this study is to investigate the level of measurement uncertainty of three different GNSS receivers: Leica GS15, Sokkia GCX2 and Satlab SL300. The method in this study is based mainly on the method proposed by HMK - Geodatakvalitet 2015 (Manual in measurement and map issues – Geographic data quality 2015 [author’s translation]) by Swedish Lantmäteriet for "Evaluation of measurement uncertainty in Network RTK [author’s translation]”. Some corrections and additions are made to this method but the basis of the method is retrieved from there. Formulas are used to calculate radial deviation and limit requirements for these. Even standard deviations and radial mean deviations as well as tolerances for these are calculated. The field measurements are made on two RIX 95-points. This is done repeatedly to get up to 20 measurements. The GNSS receivers are mounted on a tripod with a tribrach that is centered over the known points. The main finding from this study is that all investigated receivers, apart from four overriding values for the Leica GS15, perform better than specified by their manufacturers. However, Sokkia GCX2 and Satlab SL300 are approved with uncertainties within the calculated tolerances. The Leica GS15 instrument is very close to meeting the demands but does not reach all the way. A committed error during the performed measurements with the Satlab SL300 makes its evaluation based on 19 instead of 20 measurements. Still, calculations are performed on the collected data that resulted in low measurement uncertainties well below the manufacturer's specified uncertainty. The study was conducted during five weeks in May and June 2017.
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Sarapirome, Sunya. "A terrain evaluation system and GIS for road corridor selection applicable to intermontane basins in northern Thailand." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39529.
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The purpose of this study is to develop a terrain evaluation system for road corridor selection applicable to the intermontane basins in northern Thailand. The first stage involves database construction of the terrain factors which have a direct effect on construction costs. These factors are land cover, topography and landforms, surficial geology, soil strength, topsoil removal, difficulty of excavation, embankment height, construction materials, and drainage characteristics. Remote sensing and terrain evaluation techniques, field investigations and geotechnical laboratory tests are used to prepare maps of these terrain factors. The resulting maps are converted into digital database form as map layers by using Geographical Resources Analysis Support System (GRASS)--a raster-based Geographic Information System (GIS).<br>These factors are incorporated into cost models. These are constructed using local engineering cost assessments which control the selection and specification of terrain factors. Under the GRASS environment the digital map layers of different terrain attributes are converted, based on the cost models, into cost surfaces (cost per unit area). The cost surfaces are subsequently combined into an integrated terrain-cost model.<br>With different assigned end points and cost models, the applications of the single theme cost surfaces and the integrated terrain-cost models to least-cost route selection are provided. An existing road network can be incorporated in these applications. The quality and benefits of the database and system developed related to terrain conditions, data capture by remote sensing, GIS manipulation and modelling, and cost modelling are discussed.
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Tuvesson, Otto. "Integrating GIS and multicriteria analysis in the search for roadside bombs." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-9675.
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The idea of this study is to test if it is possible to use a modified Multi Critera Analysis (MCA) to automatically identify probable sites for roadside bombs in a country like Afghanistan. The intention is to create a sieving method that saves time when evaluating the threat in large areas. As the data available in such a country is sparse the method will be able to run on as little as a topographic map and a Digital Elevation Model (DEM). The outline of the method is that features that construct a Vulnerable Point (VP) are identified on the map and then assessed by a developed formula of threat to see if they lie within an area where insurgents are known to operate. The result is then refined to show only the VPs on the road. These VPs are then converted to vector to enhance visibility at all scales. The constructed method does work on the data in this study but needs to be further evaluated on more complex data.
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Bueno, Régis Fernandes. "Monitoração, por GPS, de deslocamentos em estruturas com carga dinâmica." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-08012008-144719/.
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A monitoração dinâmica de pontes rodoviárias através da determinação de deslocamentos espaciais é uma das atuais áreas de interesse da geodésia. A tecnologia de posicionamento por satélite é uma das ferramentas disponíveis para este fim e foi avaliada nesta pesquisa. Verifica-se que o GNSS pode contribuir para com o monitoramento dinâmico de estruturas e nos últimos anos se observam aplicações em grandes pontes estaiadas na Ásia, na Europa e na América do Norte. No presente estudo analisou-se a aplicação desta tecnologia em uma estrutura mais rígida, sob vinculo com uma rede de referência única e sob as condições apresentadas pela região brasileira. Foram realizados ensaios em um shaker, na Base de Calibração de Instrumentos Geodésicos da USP e na estrutura do Viaduto Ascendente 19 da rodovia dos Imigrantes, empregando-se a tecnologia GPS e análise modal. A partir de determinações no método relativo cinemático obtiveram-se os deslocamentos tridimensionais e a freqüências do primeiro modo de vibração da estrutura. A metodologia aplicada e os resultados obtidos demonstram a potencialidade do método também para estruturas mais rígidas e sob condições características da região brasileira, que diferem de outras partes do globo no que tange a tecnologia GPS. Ao final é sugerida uma Proposta Básica de Metodologia para a Monitoração de Estrutura com Carga Dinâmica pela Utilização de GNSS.<br>The dynamic monitoring of road bridges though spatial displacements is one of the geodetic areas of interests. The satellite positioning technologies are one of the disposed tools for this task and were evaluate by present research. One verifies that GNSS can contribute for the dynamic monitoring of structures, and has applied for this task in the last years to large cable stayed bridges on Asia, on Europe and on North America. On the present study, one analyses the use of this technology in a more rigid structure, tied to a unique reference network and under Brazilian region conditions. Were realized essays over a shaker on USP Geodetic Instrumental Calibration Base and over the Imigrantes Roadway Ascending Viaduct 19 employing the GPS technology and modal analysis. By determinations in the kinematics relative method ones obtain the tridimensional displacements and the frequency of first modal shape of the structure. The applied methodology and its obtained results demonstrate the potentiality of this method for more rigid structure too, and under Brazilian region characteristics. At the end is proponed a Methodological Basic Proposal for Dynamic Charged Structure Monitoring thru GNSS Employment.
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Ekberg, Fredrik. "An approach for representing complex 3D objects in GIS applied to 3D properties." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-139.
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<p>The main problem that is addressed in this thesis is how to represent complex three-dimensional objects in GIS in order to render a more realistic representation of the real world. The goal is to present an approach for representing complex 3D objects in GIS. This is achieved by using commercial GIS (ArcGIS), applied to 3D properties. In order to get a clear overview of the state-of-the-art of 3D GIS and the current 3D cadastral situation a literature study was carried out. Based on this overview it can be concluded that 3D GIS still is in its initial phase. Current 3D GIS developments are mainly in the area of visualisation and animation, and almost nothing in the area of spatial analysis and attribute handling. Furthermore, the literature study reveals that no complete solution has been introduced that solves the problems involved in 3D cadastral registration. In several countries (e.g. Sweden, Denmark, Norway, Netherlands, Israel, and Australia) 3D properties exists in a juridical framework, but technical issues such as how to represent, store, and visualize 3D properties has not yet been solved. Some countries (Sweden, Norway, and Australia) visualize the footprints of 3D property units in a base map. This approach partly solves some technical issues, but can only represent 3D objects in a 2.5D environment. Therefore, research in how to represent complex objects in GIS as ‘true’ 3D objects is of great need.</p><p>This thesis will emphasize MultiPatch as a geographic representation method to represent complex 3D objects in GIS. A case study will demonstrate that complex objects can be visualized and analysed in a commercial GIS, in this case ArcGIS. Most commercial GIS software available on the market applies a 2.5D approach to represent 3D objects. The 2.5D approach has limitations for representing complex objects. There is therefore a need of finding new approaches to represent complex objects within GIS. The result shows that MultiPatch is not an answer to all the problems within 3D GIS but a solution to some of the problems. It still requires a lot of research in the field of 3D GIS, especially in development of spatial analysis capabilities.</p><br><p>Det huvudsakliga problemet i denna uppsats är hur komplexa tre-dimensionella objekt kan representeras i GIS för att återge verkligheten mer realistiskt. Målet är att presentera ett tillvägagångssätt för att representera komplexa 3D-objekt i GIS. Detta har uppnåtts genom att använda ett kommersiellt GIS tillämpat på 3D-fastigheter. En litteraturstudie har genomförts för att erhålla en klar översikt över det senaste inom 3D-GIS och över den aktuella situationen inom 3D-fastigheter. Grundat på översikten kan slutsatsen dras att 3D-GIS bara är i sin begynnelsefas. Den aktuella utvecklingen inom 3D-GIS har huvudsakligen fokuserat på visualisering och animering och nästan ingenting inom rumsliga analysmetoder och hantering av attribut. Litteraturstudien visar också att ingen fullständig lösning för de problem som finns inom 3D-fastighetsregistrering har introducerats. I flera länder, t.ex. Sverige, Danmark, Norge, Nederländerna, Israel och Australien, existerar 3D-fastigheter idag i juridiska termer, men de tekniska problemen som t.ex. hur 3D-fastigheter ska representeras, lagras och visualiseras har inte ännu lösts. Vissa länder (Sverige, Norge och Australien) visualiserar idag en projektion av 3D-fastigheterna på en fastighetskarta. Den här metoden löser endast några av de tekniska problemen och kan endast representera 3D-objekt i en 2,5D-miljö. Därför är forskning inom hur komplexa objekt kan representeras i GIS som s.k. ”sann” 3D av betydelse.</p><p>Den här uppsatsen framhäver MultiPatch som en datatyp för att representera komplexa 3D-objekt i GIS. En fallstudie visar att komplexa objekt kan visualiseras och analyseras i ett kommersiellt GIS, i det här fallet ArcGIS. De flesta kommersiella GIS som är tillgängliga på marknaden använder 2,5D-metoden för att representera 3D-objekt. 2,5D-metoden har vissa begränsningar för att representera komplexa objekt och därför finns det ett behov att finna nya tillvägagångssätt för att representera komplexa objekt inom GIS. Resultaten kommer att visa att MultiPatch inte är någon fullständig lösning till alla problem inom 3D-GIS men en lösning på några av problemen. Det krävs fortfarande mycket forskning inom 3D-GIS, särskilt inom utveckling av rumsliga analysmetoder.</p>
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Van, Niekerk Susan. "The integration of GIS technology into demographic and quality of life surveying of informal settlements : Nelson Mandela Bay, South Africa." Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/881.
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A number of mostly informal areas in Nelson Mandela Bay have experienced rapid expansion over the past decade or so. Census data available for these areas is outdated and does not provide enough information for local authorities to accurately plan for tasks such as service delivery management and resource allocation. In this dissertation, a GIS based demographic and Quality of Life study of informal settlements and previously disadvantaged areas within Nelson Mandela Bay is undertaken to address this issue. The study aims to integrate GIS technology into a demographic and Quality of Life survey to significantly improve the collection, analysis, interpretation, display and management of survey data and to provide the accurate and necessary updates required between census collections. Data relating to informal settlements were captured from aerial photographs and satellite imagery and demographic and Quality of Life data were collected from field surveys. The results demonstrated that the use of GIS technology provided more accurate information for demographic variables, including the number of dwellings, dwelling type, size of the population and population dynamics. A specific demographic trend observed through spatial analysis included the identification of backyard shacks predating formal structures in settlements. The analysis and representation of the Quality of Life field survey data in GIS demonstrated how residents' perceptions of problems and issues in their neighbourhoods are better interpreted, understood and managed when analyzed within a spatial context. This research concluded that GIS based demographic and QOL studies are vital for providing accurate social and spatial information for municipalities, particularly in urban environments of developing countries, and for providing the necessary updates to censuses occurring every ten years.
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Botha, Paparouzkja. "Study of the implementation of the Code of Conduct and Ethical Standards in the South African Quantity Surveying Industry." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/73462.
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Over the past few years there is an increase in globalization and construction industry companies are becoming more aware of the environmental and social aspects in construction projects. Companies have to make a profit and carry out an obligation towards the community. The reason for introducing codes of conduct is to ensure that companies and persons within the construction industry become more socially responsible and adopt it into their daily businesses due to community pressures. It is essential to enforce codes of conduct throughout the construction industry professions, including all stakeholders and team members within the construction industry.
This study has sought to determine the main reasons why some quantity surveyors might not always apply the code of conduct in an ethical and professional manner, as well as to identify possible ways how the code of conduct can be improved, be upheld and implemented more successfully in South Africa.
Questionnaires were used to collect data from some quantity surveyors in South Africa. The aim of the questionnaire was to identify how some quantity surveyors implement the code of conduct, where the possible gaps in the code of conduct are and how the current code of conduct can be improved.
The data determined that the code of conduct needs to be regularly improved in order to stay up to date with current ethical situations that quantity surveyors face daily in South Africa, as well as that some quantity surveyors have a lack of education and proper understanding of the codes of conduct, lack of keeping up to date with the Code and the guidance in which they serve.<br>Dissertation (MSc)--University of Pretoria, 2020.<br>Construction Economics<br>MSc (Quantity Surveying)<br>Unrestricted
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Tims, Willem. "GIS model for the Land Use and Development Master Plan in Rwanda." Thesis, University of Gävle, Ämnesavdelningen för samhällsbyggnad, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-4975.
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<p>This thesis was aimed at the development of a Geographical Information System (GIS) based model to support the Rwanda Land Use and Development Master Plan. Developing sustainable land management is the main task of this master plan. Stakeholder’s involvement was of key importance. Their demands should be analysed and visualised to support discussions and the decision-making process. Spatial Multicriteria Decision Analysis (MCDA) is a proven method for land-use planning purposes. However, most land-use planning applications focus on a specific theme, such as urban development. In addition, land-use planning is often limited to a relatively small area. This thesis focused at the development of a countrywide GIS model, containing all land-uses accommodated in three main land-use categories: urban, agriculture and conservation. The GIS model was largely based on the Land-Use Conflict Identification Strategy (LUCIS) model. Many of the goals, objectives, and subobjectives that described the earlier mentioned land-use categories were adopted from the original model. However, a significant number of them were dropped, and new were created to suit the Rwandan situation. Stakeholder’s involvement was realized by assigning weights to the goals and preference maps. The Analytical Hierarchy Process (AHP) was used as weighting method. ESRI’s ArcGIS ModelBuilder was used to give the model shape in the GIS. Firstly, suitability maps were created of all elements in the model. The suitability maps were then transformed into preference maps by weighting them. In the next step the preference maps were collapsed in three classes: low, medium and high preference. Finally, the preference maps of the three land-use categories were combined, in order to visualize conflict areas. Ortho photos proved to be useful when acting as reference for the suitability and preference maps. Despite a large number of missing datasets, the GIS model was executed to simplify the understanding. However, many of the obtained results were unreliable because of the incompleteness of datasets, and can therefore not be used for decision-making. Unfortunately, due to the stage of the project it was not possible to obtain weights from the stakeholders, and should therefore be done when the time is right. Right Choice DSS, a very user-friendly decision support application, was proposed to use for calculating weights. To conclude, the developed GIS model integrated countrywide land-use suitability mapping and stakeholders’ wishes that can be used for discussions and decision making.</p>
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Parianos, Andreas, and Tobias Dahlqvist. "En utredning av tekniken "mobile mapping" i kommunal verksamhet." Thesis, University West, Division of Land Surveying and Mathematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-2521.
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<p>This thesis work is intended to analyze whether the municipalities has a need for the new technology of mobile mapping.</p><p>Mobile mapping consists of the technologies of laser scanning, photographing and positioning of streets and roads in city environment and in the countryside. When these technologies are operating together a georeferenced three-dimensional image model is created, which has specific coordinates that states its position on the surface of the earth. Thanks to the laser scanning process even measuring can be performed in this model.</p><p>The municipal sector consists of many different departments which use visual spatial information. These departments are an interesting target group for this system. Specific departments within the municipal sector, which we considered were the most suitable, have been selected. Individuals within these departments have replied to a <em>questionnaire</em> where several statements were given. The statements are constructed so that the replies that are received as much as possible describe the need for this new technology. In addition to the <em>questionnaire</em> a number of telephone- and in-depth interviews have been done in purpose of creating a basis which is as solid as possible.</p><p>The results that have been obtained indicate that there is a rather considerable demand for the technology. The majority of the asked professions have given replies which hint that they would appreciate visual measurable spatial information in accurate and detailed 3D-models. The telephone interviews have pointed in this direction as well.</p><p>Since a municipality is organized of a large number of departments which each have a need for the technology, a reference can be made to the expression “many a little makes a mickle”. In other words, the municipal need for the technology is considerable since many different units find their own uses for mobile mapping.</p><p>We have after this investigation obtained a result which implies that mobile mapping would be a good investment for the municipal sector.</p>
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Barbera, Jack. "Combining research in physical chemistry and chemical education: Part A. The femtosecond molecular dynamics of small gas-phase anion clusters. Part B. Surveying student beliefs about chemistry and the development of physical chemistry learning tutorials." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3256464.
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Tavakoli, Saman. "Construction of a solid 3D model of geology in Sardinia using GIS methods." Thesis, University of Gävle, Department of Technology and Built Environment, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-3773.
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<p><p>Abstract</p><p>3D visualization of geological structures is a very efficient way to create a good understanding of geological features. It is not only an illustrative way for common people, but also a comprehensive method to interpret results of the work. Geologists, geophysics engineers and GIS experts sometimes need to visualize an area to accomplish their researches. It can show how sample data are distributed over the area and therefore they can be applied as suitable approach to validate the result. Among different 3D modeling methods, some are expensive or complicated. Therefore, such a methodology enabling easy and cheap creation of a 3D construction is highly demanded.</p><p>However, several obstacles have been faced during the process of constructing a 3D model of geology. The main debate over suitable interpolation methods is the fact that 3D modelers may face discrepancies leading to different results even when they are working with the same set of data. Furthermore, most often part of data can be source of errors, themselves. Hence, it is extremely important to decide whether to omit those data or adopt another strategy. However, even after considering all these points, still the work may not be accurate enough to be used for scientific researches if the interpretation of work is not done precisely. This research sought to explain an approach for 3D modeling of Sedini platform in Sardinia, Italy. GIS was used as a flexible software together with Surfer and Voxler. Data manipulation, geodatabase creation and interpolation test all have been done with aid of GIS. A variety of interpolation methods available in Surfer were used to opt suitable method together with Arc view.</p><p>A solid 3D model is created in Voxler environment. In Voxler, in contrary to many other 3D types of software there are four components needed to construct 3D. C value as 4<sup>th</sup> component except for XYZ coordinates was used to differentiate special features in platform and do gridding based on chosen value. With the aid of C value, one can mark layer of interest to identify it from other layers.</p><p>The final result shows a 3D solid model of the Sedini platform including both surfaces and subsurfaces. An Isosurface with its unique value (Isovalue) can mark layer of interest and make it easy to interpret the results. However, the errors in some parts of model are also noticeable. Since data acquisition was done for studying geology and mineralogy characteristics of the area, there is less number of data points collected per volume according to the main goals of the initial project. Moreover, in some parts of geological border lines, the density of sample points is not high enough to estimate accurate location of lines.</p><p>The study result can be applicable in a broad range of geological studies. Resource evaluation, geomorphology, structural geology and GIS are only a few examples of its application. The results of the study can be compared to the results of similar works where different softwares have been used so as to comprehend pros and cons of each as well as appropriate application of each software for a special task.</p><p> </p><p> </p><p><em>Keywords: GIS, Image Interpretation, Geodatabase, Geology, Interpolation, 3D Modeling</em></p><p> </p><p> </p></p><p> </p>
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Scarfe, Bradley Edward. "Oceanographic Considerations for the Management and Protection of Surfing Breaks." The University of Waikato, 2008. http://hdl.handle.net/10289/2668.
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Although the physical characteristics of surfing breaks are well described in the literature, there is little specific research on surfing and coastal management. Such research is required because coastal engineering has had significant impacts to surfing breaks, both positive and negative. Strategic planning and environmental impact assessment methods, a central tenet of integrated coastal zone management (ICZM), are recommended by this thesis to maximise surfing amenities. The research reported here identifies key oceanographic considerations required for ICZM around surfing breaks including: surfing wave parameters; surfing break components; relationship between surfer skill, surfing manoeuvre type and wave parameters; wind effects on waves; currents; geomorphic surfing break categorisation; beach-state and morphology; and offshore wave transformations. Key coastal activities that can have impacts to surfing breaks are identified. Environmental data types to consider during coastal studies around surfing breaks are presented and geographic information systems (GIS) are used to manage and interpret such information. To monitor surfing breaks, a shallow water multibeam echo sounding system was utilised and a RTK GPS water level correction and hydrographic GIS methodology developed. Including surfing in coastal management requires coastal engineering solutions that incorporate surfing. As an example, the efficacy of the artificial surfing reef (ASR) at Mount Maunganui, New Zealand, was evaluated. GIS, multibeam echo soundings, oceanographic measurements, photography, and wave modelling were all applied to monitor sea floor morphology around the reef. Results showed that the beach-state has more cellular circulation since the reef was installed, and a groin effect on the offshore bar was caused by the structure within the monitoring period, trapping sediment updrift and eroding sediment downdrift. No identifiable shoreline salient was observed. Landward of the reef, a scour hole ~3 times the surface area of the reef has formed. The current literature on ASRs has primarily focused on reef shape and its role in creating surfing waves. However, this study suggests that impacts to the offshore bar, beach-state, scour hole and surf zone hydrodynamics should all be included in future surfing reef designs. More real world reef studies, including ongoing monitoring of existing surfing reefs are required to validate theoretical concepts in the published literature.
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Lin, Sheng-Yi, and 林聖宜. "Applications of GPS Satellite Surveying to Engineering practices." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/69309196283703863127.
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碩士<br>國立中央大學<br>土木工程研究所<br>86<br>Using the relative carrier-phase theory, we are surely to have cm- even mm-level positioning accuracy presently. Because the GPS satellite is not affected by weather and intervisibility between stations, it will be very powerful in engineering practice.
The main purposes of the thesis are: Firstly, I introduce and compare the practical applications by a series of the relative satellite surveying techniques using carrier-phase observations. Secondly, I use an interpolation model to solve the transformation problems for the control survey. Emphasizing the original characteristics of the satellite surveying, I also use the rapid static relative positioning for planimetry part, and rapid static / dynamic relative positioning for heighting, respectively. Then I discuss the accuracy and possibility to apply the satellite surveying techniques to local coordinate systems. Thirdly, I design three new practical approaches to engineering surveying by the GPS satellite surveying, combining with the total station.
In this paper, I prove that it is possible to use a single frequency receiver for a 9 km baseline. The relative distance error of planimetric control surveying can reach a ratio of at least 1/20000 by applying the satellite surveying techniques with a proper interpolation model. And the accuracy is 2-cm at maximum in height determination. Combined with a total station, I find out that the geodetic positioning accuracy of the target point which not can be occupied by any surveying instrument can reach to an order of milimeters.
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Kuo, Long-Chen, and 郭隆晨. "High Precision GPS Surveying for Crustal Deformation Studies." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/21235652000865997084.
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博士<br>國立交通大學<br>土木工程系<br>89<br>Based on the least squares theory, the error propagation between the site coordinate and velocity are derived and discussed in the thesis. The best quality of site coordinates with estimated velocities are determined at the middle epoch of the observation period. The uncertainty in site velocity can be expressed as a function of the single measurement position accuracy. This function can be used for the planning of an experiment, we can easily know how long it should take to acquire a data set with a given rate accuracy, or how offen an experiment must be repeated within a fixed period to obtain that accuracy. The analysis of a repeated experiment reveals that the rate uncertainties derived directly from covariance are comparable with that from the function, and the difference is less than 3%. The function is proved to be correct and useful by using the analysis of real data in the repeated campaigns. Longer period experiment and higher single measurement accuracy is the most efficient way to reduce the uncertainty in a site velocity estimate.
Collecting GPS data under the weather condition of high temperature, high humidity and using observables of lower elevation angle result in larger tropospheric refraction errors on GPS height. The relationships between the meterological errors and the resulting bias on GPS height are derived theoretically and expressed as functions by using analytical and regressive analysis. It is found that applying the method of troposphere zenith delay estimates, considering the elevation-dependent weighting of observations, estimating the troposphere gradients, using Niel mapping function, and including low-elevation angle GPS data into the processing would be able to improve the precision of coordinates effectively.
Analyzing annually repeated GPS data from 1992 to 1999, we found the baselines repeatabilities are 5-6 mm in horizontal component, and 16 mm in vertical component. The expected precision of site velocity at 4-5 mm/y can be reached within 2-3 years. Repeatabilities of 3-5 mm in horizontal vector and 11-15 mm in vertical component are found at the continuously recording stations. To obtain the site velocity of either campaign-surveyed or continuous GPS stations with an accuracy of 2～3 mm/y, the optimal total time span of observations is about 3 years.
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HSU, HAO HSIUNG, and 徐浩雄. "Whitening Filter Applied to GPS Kinematic Satellite Surveying." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/50230424988366702217.
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碩士<br>國立中央大學<br>土木工程研究所<br>88<br>In the practice of kinematic and rapid static surveying, the key point to reach the target of precision and efficiency while using carrier phase for location is how to obtain quickly accurate integers of ambiguity. However design matrix can vary because of the high correlation between parameters and longer observation time depending geometric satellite''s improvement. Therefore whitening filter is a technique reflecting the high correlation in the space of parameters on another little lower correlation, causing the effects of mathematics chance turn to be the same as geometric satellite change, and get the result within a short observation period.
Whitening filter uses crout factorization to decompose an positive-definite symmetrical matrix into the continue multiplication of diagonal matrix and unit upper/lower triangular matrix. Applying the specifics of its diagonal matrix condition to covariance matrix can reduce the number of solution ways for integral ambiguity. The second part uses double differences to get location parameters and integer ambiguity. Then estimates single differences ambiguity for adopting the latter process to find out parameters of location and time. The third part deals with kinematic surveying. Using characteristics of mixed model to convert vector of variance into vector of residuals with the purpose of reducing unknown parameters, so that kinematic surveying can be more efficient in the satellite surveying.
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Watson, CS. "Satellite altimeter calibration and validation using GPS buoy technology." 2005. http://eprints.utas.edu.au/254.
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Satellite altimeters have become an important tool for the study of global and regional mean sea level change, offering near global coverage and unprecedented accuracy. Issues of calibration and validation remain central to their ability to determine estimates of change at accuracies of better than 0.5 mm/yr.This Thesis provides an absolute calibration of the TOPEX/Poseidon (T/P) and Jason-1 satellite altimeters, undertaken in Bass Strait, Australia. The research provides a contribution to the international calibration effort, with the Bass Strait site situated as the only one of its kind in the Southern Hemisphere. A unique in situ absolute calibration methodology is presented, reliant on the episodic deployment of GPS equipped buoys at an offshore comparison point. In contrast to other calibration studies, data from the GPS buoys are used to solve for the absolute datum of an offshore oceanographic array (incorporating a pressure sensor, temperature and salinity recorders and a current meter array). Combined with data from a coastal tide gauge and a regional GPS network, the methodology enables the cycle-by-cycle computation of absolute bias, without the necessity of estimating a marine geoid. Emphasis within this Thesis is given to the design and development of the GPS equipped buoys, in addition to the standardisation requirements of the geodetic analysis. The GPS buoy design is applied to both the altimeter calibration problem, in addition to a near shore application involving the calibration of tide gauges in the Antarctic and Sub-Antarctic.The attention to standardisation ensures comparable estimates of in situ and altimeter sea surface height. Differences at the 9 mm level for the pole tide displacement and plus or minus 5 mm for the solid Earth tide displacement are revealed when using the GAMIT GPS analysis suite.The implications of non-standardisation are further illustrated with the presentation of time series analysis from various continuous GPS datasets. Absolute bias and 1-sigma uncertainties from a formal error budget are 0 plus or minus 14 mm for T/P and +152 plus or minus 13 mm for Jason-1 (for the GDR POE orbits, computed over the calibration phase, 18 Jan 2002 14 Aug 2002). Results over the duration of the T/P mission confirm a dependence on the choice of Sea State Bias (SSB), with the overall mean absolute bias not statistically different from zero. Extending the comparison period between Jason-1 cycles 1 to 101 (18 Jan 2002 06 Oct 2004) reduces the Jason-1 mean absolute bias by approximately 10 mm and reveals a significant slope of -7.6 plus or minus 5.6 mm per year.Whilst the cause for the significant absolute bias remains unexplained, the source of the drift appears attributable to the microwave radiometer, observed to be measuring drier over time (-5.9 plus or minus 2.1 mm/yr). Drift of the POE orbit relative to the JPL GPS orbit is shown to account for the remaining trend observed at the Bass Strait site.After considering geographically correlated errors, absolute bias results show excellent agreement with other international calibration studies.These results aid in understanding the performance of both the T/P and Jason-1 altimeters, further underscoring calibration and cross calibration of altimeters as essential for the study of low frequency oceanographic processes, including regional and global mean sea level change.The inference of geographically correlated orbit errors, and the significant unexplained Jason-1 absolute bias emphasises the need for maintaining globally distributed verification sites and makes it clear that further work is required to improve our understanding of the Jason-1 instrument and its algorithm behaviour.
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Chen, Wen-Shih, and 陳文石. "Combination of FRID and e-GPS Applied to Cadastral Surveying." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/05612019125446864700.
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碩士<br>國立成功大學<br>地球科學系專班<br>95<br>There is a high percentage of loss of land surveying piles/marks in Taiwan each year as the result of road development projects in urban planning, repaving of road surfaces, the use of private land for construction – or sabotage, and hence there exists a great need to reinstall these piles that adds more workload and a higher degree of difficulty for cadastral surveying crews. As such, this study shall explore the means to combine the most advanced e-GPS surveying technology with RFID technology, as well as how to implement the study results into the various tasks of cadastral surveying, with the objectives to maintain the integrity of cadastral records, enhance the efficiency of cadastral surveying, strengthen the management of the surveying piles/marks, and finally lighten the workload of cadastral surveying crews in order to speed up cadastral surveying.
RFID is a non-contact frequency identification system capable of reading, writing and storing information, as well as radio communication; this technology is used widely nowadays in logistical, warehouse management. If the built-in UID feature can be combined with surveying piles/marks to provide identification and data retrieval capabilities, then they may become “intelligent” piles/marks able to identify themselves. e-GPS is a real-time, dynamic surveying method applying the ultra precise positioning capability of GPS and communication technologies, having the abilities of point guidance and resetting.
It is the finding of the study testing different RFID frequencies under different environments that two lower frequencies, 125KHz and 13.56MHz possess the characteristics of mature technology, being unaffected by water content, better surface penetrability and low equipment cost; they are also able to detect electronic label signals under puddles and the coverage of soil. Although the frequency 13.56MHz is unable to detect signals under the influence of metals, yet with proper insulation packaging that is able to reduce the influence from metal surfaces, this frequency is still suitable candidate for the production of “intelligent” surveying piles/marks. According to the results from the analysis, it is suggested that the 125KHz-based RFID system may be given the priority in the implementation of surveying application systems.
If RFID and e-GPS can be combined and applied in cadastral surveying tasks, then their capabilities of guidance, identification, reset and point data processing may enhance the efficiency of cadastral survey, so that the management may be more convenient, and current operating procedures of cadastral surveying may be unaffected.
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李春謀. "A study on the GPS satellite^^surveying knowledge management systems." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/31473350381315168317.
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