• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 76
  • 9
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 105
  • 105
  • 44
  • 37
  • 35
  • 24
  • 22
  • 19
  • 18
  • 16
  • 10
  • 10
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

PRINCIPAL COMPONENTS AND TEXTURE ANALYSIS OF THE NS-001 THEMATIC MAPPER SIMULATOR DATA IN THE ROSEMONT MINING DISTRICT, ARIZONA (GEOLOGIC, DIGITAL IMAGE PROCESSING, TEXTURE EXTRACTION).

Yang, Hsien-Min, 1957- January 1985 (has links)
No description available.
52

Segmentação e classificação de imagens destinadas ao mapeamento digital do Parque Nacional da Serra dos Órgãos (PARNASO) / Images segmentation and classification for digital mapping to the Parque Nacional da Serra dos Órgãos (PARNASO).

Robson Lopes de Freitas Junior 18 March 2011 (has links)
Na perspectiva ambiental, o Parque Nacional da Serra dos Órgãos (PARNASO) é o Parque Nacional mais pesquisado no Brasil e configura-se como uma importante Unidade de Conservação inserida no estado do Rio de Janeiro, devido à sua importância ambiental para o estado. Localizado em quatro municípios da região serrana: Teresópolis, Petrópolis, Magé e Guapimirim foi constatado que essa área tem passado por alguns problemas, relativamente recentes, de ocupação desordenada devido à expansão urbana em sua vizinhança caracterizada por pressão antrópica. Através do processamento de imagens digitais, mais especificamente as etapas de segmentação e classificação, foi possível ilustrar o processo de ocupação humana por meio de documentos cartográficos. Além de estes processos possibilitarem a geração de mapas de uso da Terra e cobertura vegetal, com o intuito de auxiliar e dar fomento à execução de atividades, o mapeamento digital configura-se numa importante ferramenta para a análise ambiental, contribuindo para o posterior zoneamento da área de estudo. Adotaram-se classes temáticas de uso e ocupação da Terra com o propósito de permitir a classificação das imagens digitais trabalhadas. São elas: afloramento rochoso, área urbana, agricultura e vegetação. Estudos foram feitos no sentido de indicar e explorar as funcionalidades das ferramentas SPRING e DEFINIENS e resultados foram comparados a partir do uso de imagens LANDSAT, CBERS, SPOT e IKONOS chegando-se a resultados de que no sistema SPRING, os melhores parâmetros a serem escolhidos foram similaridade 10 e área 400. Já para o sistema DEFINIENS, constatou-se que o processo de segmentação multinível permitiu o alcance de resultados mais rápidos, do ponto de vista computacional, do que o processo de segmentação único utilizado normalmente entre os sistemas de processamento de imagens digitais como o SPRING. Já sob a ótica do processo de classificação de imagens, a pesquisa constituiu em avaliar este mecanismo por meio de dois indicadores: o de exatidão/acurácia e o índice Kappa. Neste sentido, observaram-se tendências de melhores resultados no sistema SPRING. / In the environmental point, the National Park of Serra dos Órgãos (PARNASO) is the more studied National Park in Brazil and is configured as an important Unit Conservation in the Rio de Janeiros state, because the environmental importance for the state. Located in four cities to the Serrana region: Teresópolis, Petrópolis, Magé and Guapimirim were evidenced that this area has passed for some problems, relatively recent, of disordered occupation because the urban expansion in its neighborhood characterized for human pressure. Through the digital image processing, more specifically the stages of segmentation and classification, were possible to illustrate the occupation process human being by means of cartographic documents. Beyond this process to make possible the generation of use the Land and vegetal covering maps, with the intention for assisting and giving foments to the execution of activities, the digital mapping is configured in an important tool for the environmental analysis, and the posterior zoning to the study area. Thematic classes of Land use and occupation with the intention had been adopted to allow the classification to the worked digital images. They are: rocky outcrop, urban area, agriculture and vegetation. Studies had been made in the direction to indicate and to explore the functionalities of tools SPRING and DEFINIENS and results they had been compared from use of images LANDSAT, CBERS, SPOT and IKONOS arriving itself resulted in SPRING system, the best parameters to be chosen they had been 10 similarity and area 400. Already for DEFINIENS system, it was evidenced that the segmentation process multilevel allowed the reach of faster results, to the computational view, to the only process of segmentation used normally enters the systems of digital image processing as the SPRING. Already to another view, the process of images classification, the research constituted in evaluating this mechanism by means of two pointers: accuracy/exactness and the Kappa index. In this direction, resulted trends of better had been observed in the SPRING system.
53

Digital plan lodgement and dissemination

Hobson, Adrian, Surveying & Spatial Information Systems, Faculty of Engineering, UNSW January 2004 (has links)
In Australia, in recent years there has been increasing demand for more streamlined lodgement of cadastral plans and for their later dissemination. There are a number of approaches to meeting this demand, one of which is developed in detail in this dissertation. The current status of digital lodgement and Digital Cadastral Databases (DCDB) throughout Australia and New Zealand is reviewed. Each of the states and territories in Australia and also New Zealand are examined, looking at the process involved in the lodgement of survey plans and the state of the DCDB in each jurisdiction. From this examination the key issues in digital lodgement and dissemination are extracted and a needs analysis for an Australia-wide generic system is carried out. This needs analysis is directed at technological change allied with sound cadastral principles. Extensible Markup Language (XML) is considered for the storage and transport of all the required data and to facilitate the dissemination of information over the Internet. The benefits of using XML are comprehensive, leading to its selection and the use of related technologies LandXML, Extensible Structured Query Language (XSQL) and Extensible Stylesheet Language (XSL). Vector graphics are introduced as the means to display plans and maps on the Internet. A number of vector standards and Web mapping solutions are compared to determine the most suitable for this project. A new standard developed by the World Wide Web Consortium (W3C), Scalable Vector Graphics (SVG), is chosen. A prototype Web interface and the underlying database and Web server were developed using Oracle as the database and Apache as the Web server. Each aspect of the development is described, starting with the installation and configuration of the database, the Web server and the XSQL servlet. Testing was undertaken using LandXML cadastral data and displaying plans using SVG. Both Internet Explorer and Mozilla were trialled as the Web browser, with Mozilla being chosen because of incompatibilities between Internet Explorer, LandXML and SVG. An operational pilot was created. At this stage it requires manual intervention to centre and maximise a plan in the display area. The result indicates that an automated system is feasible and this dissertation provides a basis for further development by Australian land administration organisations.
54

Assessment and correction of DEM generation from airborne and space borne radar systems with reference to geo-hazard identification in the Cameron Highlands, Malaysia.

Ahmad, Baharin Bin, Biological, Earth & Environmental Sciences, Faculty of Science, UNSW January 2008 (has links)
This research assesses the accuracy of SRTM and AIRSAR DEMs acquired over the mountainous-hillands of Cameron Highlands with DEMs generated from Digital Aerial Photograph (DAP) with a fine (2 m) spatial resolution and height resolution of about 0.5 m. The ground control points used for generating stereo models from the DAP were acquired during field work using GPS which achieved accuracy better than 2 cm in most cases. To overcome the difficulty of overlaying the DEMs with the DAP DEM as no features can be easily identified on both the images, therefore a technique of using transects and contours generated from the DEMs were used to correct the horizontal displacement. For AIRSAR DEM, comparing the accompanying AIRSAR composite images was also employed. These then allowed an analysis of the height accuracy to be undertaken. The height of both the AIRSAR and SRTM DEMs were also corrected by applying Linear Regression Models. These models were produced by comparing pixels obtained from points, profiles and an area. Once again the corrected DEMs were assessed. Finally the extracted profiles and contours from the corrected SRTM and AIRSAR were compared with the reference DEM. From the comparisons, the horizontal errors were found to be about one and the half pixels (138.72 m: for SRTM) to the east and 1 pixel (10 m: for AIRSAR) to the south. The SD of height differences of the SRTM and AIRSAR DEMs using 90% data were 9.2 m and 5.2 m with profiles comparison; 10.4 m and 5.4 m with area comparison; 10.8 m and 2.4 m with GPS GCPs comparison respectively. From the three comparisons, the means of height differences are 5.2 m, 6.1 m and 15.2 m for SRTM and 8.1 m, 8.3 m and 7.9 m for AIRSAR DEM. The results suggest there is height offset in the AIRSAR DEM. When both heights of DEMs were corrected, the generated contours are close to each other and to reference contours. Using contour colours images and height modelling, the corrected DEM was found to have the potential to detect areas that prone to flash floods and mudslides.
55

A 2D visual language for rapid 3D scene design : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in the University of Canterbury /

Adams, Nathan January 2009 (has links)
Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 82-93). Also available via the World Wide Web.
56

An investigation of advances in digital cartography through the mapping of West Virginia University

Duffy, Brenden. January 2003 (has links)
Thesis (M.A.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vi, 85 p. : ill. (some col.), col. maps + AVI movie and VRML computer files. Includes AVI movie and VRML files. Includes abstract. Includes bibliographical references (p. 83-85).
57

Interactive visualization tools for spatial data & metadata

Antle, Alissa N. 11 1900 (has links)
In recent years, the focus of cartographic research has shifted from the cartographic communication paradigm to the scientific visualization paradigm. With this, there has been a resurgence of cognitive research that is invaluable in guiding the design and evaluation of effective cartographic visualization tools. The design of new tools that allow effective visual exploration of spatial data and data quality information in a resource management setting is critical if decision-makers and policy setters are to make accurate and confident decisions that will have a positive long-term impact on the environment. The research presented in this dissertation integrates the results of previous research in spatial cognition, visualization of spatial information and on-line map use in order to explore the design, development and experimental testing of four interactive visualization tools that can be used to simultaneously explore spatial data and data quality. Two are traditional online tools (side-by-side and sequenced maps) and two are newly developed tools (an interactive "merger" bivariate map and a hybrid o f the merger map and the hypermap). The key research question is: Are interactive visualization tools, such as interactive bivariate maps and hypermaps, more effective for communicating spatial information than less interactive tools such as sequenced maps? A methodology was developed in which subjects used the visualization tools to explore a forest species composition and associated data quality map in order to perform a range of map-use tasks. Tasks focused on an imaginary land-use conflict for a small region of mixed boreal forest in Northern Alberta. Subject responses in terms of performance (accuracy and confidence) and preference are recorded and analyzed. Results show that theory-based, well-designed interactive tools facilitate improved performance across all tasks, but there is an optimal matching between specific tasks and tools. The results are generalized into practical guidelines for software developers. The use of confidence as a measure of map-use effectiveness is verified. In this experimental setting, individual differences (in terms of preference, ability, gender etc.) did not significantly affect performance.
58

Cadastral lease diagrams for resettlement farms in Namibia: 'digital orthophotos as an alternative to the current field surveying technique'.

Louw, Frikkie J. January 2004 (has links)
The Ministry of Lands, Resettlement and Rehabilitation of Namibia is responsible for all land issues. The resettlement of landless farmers, of the previous disadvantaged groups, is one of the issues. The Agricultural (Commercial) Land Reform Act (Act 6 of 1995) applies to the commercial land parts of the country. Under this act the government of Namibia has the first option on the purchase of commercial farms when these are offered for sale. These purchased farms will then be used to resettle the landless farmers from the communal areas. These applicants may obtain a long-term lease over the purchased commercial farms. Long-term leases are legally required to be registered in the Deeds Office. A cadastral lease diagram is required for registration. The government, through the Ministry of Lands, Resettlement and Rehabilitation, has bought approximately 130 farms for resettlement purposes. On June 2003 approximately 13 of these resettlement farms were surveyed and cadastral lease diagrams prepared for registration in the Deeds Office. The author argues that many factors have affected the slow progress of the resettlement in Namibia including the time required for the preparation of the cadastral lease diagram. The current field survey techniques, Total Stations or/and GPS, are very reliable, but are slow. The use of digital orthophotos has been shown to shorten the time to prepare the cadastral lease diagrams. The Author further argues that because digital orthophotos are available at the Surveyor-General's Office means, there are no cost implications. The cost of the cadastral lease diagrams by using digital orthophotos is only a third of the cost of using the current field survey techniques. Replacing current survey techniques with digital orthophotos or including the use of digital orthophotos, as a surveying technique would require the revision of the Land Survey Act (Act 33 of 1993) and the Survey Regulations, under section 5 of the said Land Survey Act - Government Notice No. 58 of 2002. / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.
59

Assessment and correction of DEM generation from airborne and space borne radar systems with reference to geo-hazard identification in the Cameron Highlands, Malaysia.

Ahmad, Baharin Bin, Biological, Earth & Environmental Sciences, Faculty of Science, UNSW January 2008 (has links)
This research assesses the accuracy of SRTM and AIRSAR DEMs acquired over the mountainous-hillands of Cameron Highlands with DEMs generated from Digital Aerial Photograph (DAP) with a fine (2 m) spatial resolution and height resolution of about 0.5 m. The ground control points used for generating stereo models from the DAP were acquired during field work using GPS which achieved accuracy better than 2 cm in most cases. To overcome the difficulty of overlaying the DEMs with the DAP DEM as no features can be easily identified on both the images, therefore a technique of using transects and contours generated from the DEMs were used to correct the horizontal displacement. For AIRSAR DEM, comparing the accompanying AIRSAR composite images was also employed. These then allowed an analysis of the height accuracy to be undertaken. The height of both the AIRSAR and SRTM DEMs were also corrected by applying Linear Regression Models. These models were produced by comparing pixels obtained from points, profiles and an area. Once again the corrected DEMs were assessed. Finally the extracted profiles and contours from the corrected SRTM and AIRSAR were compared with the reference DEM. From the comparisons, the horizontal errors were found to be about one and the half pixels (138.72 m: for SRTM) to the east and 1 pixel (10 m: for AIRSAR) to the south. The SD of height differences of the SRTM and AIRSAR DEMs using 90% data were 9.2 m and 5.2 m with profiles comparison; 10.4 m and 5.4 m with area comparison; 10.8 m and 2.4 m with GPS GCPs comparison respectively. From the three comparisons, the means of height differences are 5.2 m, 6.1 m and 15.2 m for SRTM and 8.1 m, 8.3 m and 7.9 m for AIRSAR DEM. The results suggest there is height offset in the AIRSAR DEM. When both heights of DEMs were corrected, the generated contours are close to each other and to reference contours. Using contour colours images and height modelling, the corrected DEM was found to have the potential to detect areas that prone to flash floods and mudslides.
60

Development of super resolution techniques for finer scale remote sensing image mapping

Li, Feng, Engineering & Information Technology, Australian Defence Force Academy, UNSW January 2009 (has links)
In this thesis, methods for achieving finer scale multi-spectral classification through the use of super resolution (SR) techniques are investigated. A new super resolution algorithm Maximum a Posteriori based on the universal hidden Markov tree model (MAP-uHMT) is developed which can be applied successfully to super-resolve each multi-spectral channel before classification by standard methods. It is believed that this is the first time that a true super resolution algorithm has been applied to multi-spectral classification, and results are shown to be excellent. Image registration is an important step for SR in which misalignment can be measured for each of many low resolution images; therefore, a new and computationally efficient image registration is developed for this particular application. This improved elastic image registration method can deal with a global affine warping and local shift translations based on coarse to fine pyramid levels. The experimental results show that it can provide good registration accuracy in less computational time than comparable methods. Maximum a posteriori (MAP) is adopted to deal with the ill-conditioned problem of super resolution, wherein a prior is constructed based on the universal hidden Markov tree (uHMT) model in the wavelet domain. In order to test this prior for MAP estimation, it is first tested in the simpler and typically ill-conditioned problem of image denoising. Experimental results illustrate that this new image denoising method achieves good performance for the test images. The new prior is then extended to SR. By combining with the new elastic image registration algorithm, MAP-uHMT can super resolve both some natural video frames and remote sensing images. Test results with both synthetic data and real data show that this method achieves super resolution both visually and quantitatively. In order to show that MAPuHMT is also applicable more widely, it is tested on a sequence of long-range surveillance images captured under conditions of atmospheric turbulence distortion. The results suggest that super resolution may have been achieved in this application also.

Page generated in 0.0642 seconds