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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Zaměření specifických prvků v areálu Admas / The surveing of specific elements in the area of Admas

Koukal, Pavel January 2017 (has links)
The diploma thesis consists of two fundamental parts. The first part is focused on scanning a section of the Admas area by a terrestrial laser scanner. This section describes the introduction to laser scanning, necessary utilities and software, fieldwork, the process from the registration of a point cloud, through point cloud processing to its connection into the S-JTSK. The second part of the thesis is mostly focused on execution of the digital model of the relief from the acquired data. It also deals with the two methods of creating a cross-sectional drawing of the area - one is based on the digital model of the relief and the other on data obtained by the polar method. The outcome of the thesis is to assess the accuracy of the topographical model, based on the comparison with the polar method.
12

Digitální model reliéfu v areálu Admas / Digital terrain model in the area of Admas

Kroupa, Ondřej January 2017 (has links)
The goal of this thesis is to scan part of the complex research center AdMaS using terrestrial laser scanner, from obtained data draw up a 3D terrain model and compare the height accuracy with conventional terrestrial measurement. The thesis is focused to software, which allow processing of point clouds and prepare the 3D model. The output of this work is the 3D terrain model and two transverse profiles for vertical comparison of two measurement methods.
13

Classificação de padrões espectrais em dados LIDAR para a identificação de rochas em afloramentos

Inocencio, Leonardo Campos 01 August 2012 (has links)
Submitted by William Justo Figueiro (williamjf) on 2015-07-09T22:32:57Z No. of bitstreams: 1 27b.pdf: 4120563 bytes, checksum: 28666d8a39aa4371e2cad8353a3b6fc2 (MD5) / Made available in DSpace on 2015-07-09T22:32:57Z (GMT). No. of bitstreams: 1 27b.pdf: 4120563 bytes, checksum: 28666d8a39aa4371e2cad8353a3b6fc2 (MD5) Previous issue date: 2012-08-01 / Petrobras - Petróleo Brasileiro S. A. / UNISINOS - Universidade do Vale do Rio dos Sinos / O presente estudo visou o desenvolvimento e aplicação de uma metodologia para a detecção e classificação de diferentes respostas espectrais em nuvens de pontos obtidas a partir de escâner a laser terrestre (Laser Scanner Terrestre) com o intuito de identificar a presença de diferentes rochas em afloramentos e a geração de um Modelo Digital de Afloramento. A ferramenta para a classificação de padrões espectrais, denominada K-Clouds, foi desenvolvida com base em análise de agrupamentos (clusters), que a partir de uma indicação do número de classes fornecido pelo usuário através da análise de um histograma dos dados, realiza a classificação da nuvem de pontos. Os dados classificados podem então ser interpretados por geólogos para uma melhor compreensão e identificação das rochas presentes no afloramento. Além da detecção de diferentes rochas, verificouse que é possível detectar pequenas alterações nas características físico-químicas das mesmas, como aquelas causadas por intemperismo e variação composicional. / The present study aimed to develop and implement a method for detection and classification of spectral signatures in point clouds obtained from Terrestrial Laser Scanner in order to identify the presence of different rocks in outcrops and to generate a Digital Outcrop Model. To achieve this objective, a software based on cluster analysis was created, named K-Clouds. This software was developed through a partnership between UNISINOS and the company V3D. This tool was designed to, beginning with an analysis and interpretation of a histogram from a point cloud of the outcrop and subsequently indication of a number of classes provided by the user, process the intensity return values. This classified information can then be interpreted by geologists, to provide a better understanding and identification from the existing rocks in the outcrop. Beyond the detection of different rocks, this work was able to detect small changes in the physical-chemical characteristics of the rocks, as they were caused by weathering or compositional changes.
14

Estimation cohérente de l'indice de surface foliaire en utilisant des données terrestres et aéroportées / Consistent forest leaf area index retrieval using ground and airborne data

Hu, Ronghai 27 August 2018 (has links)
L’indice de surface foliaire (Leaf Area Index, LAI), défini comme la moitié de la surface foliaire par unité de surface de sol, est un paramètre clé du cycle écologique de la Terre, et sa précision d'acquisition a toujours la nécessité et la possibilité d'amélioration. La technologie du scanner laser actif offre une possibilité d'obtention cohérente du LAI à plusieurs échelles, car le scanner laser terrestre et le scanner laser aéroporté fonctionnent sur le même mécanisme physique. Cependant, les informations tridimensionnelles du scanner laser ne sont pas complètement explorées dans les méthodes actuelles et les théories traditionnelles ont besoin d'adaptation. Dans cette thèse, le modèle de distribution de longueur de trajet est introduit pour corriger l'effet d’agrégation, et il est appliqué aux données du scanner laser terrestre et du scanner laser aéroporté. La méthode d'obtention de la distribution de longueur de trajet de différentes plates-formes est étudiée et le modèle de récupération cohérent est établi. Cette méthode permet d’améliorer la mesure du LAI des arbres individuels dans les zones urbaines et la cartographie LAI dans les forêts naturelles, et ses résultats sont cohérents à différentes échelles. Le modèle devrait faciliter la détermination cohérente de l'indice de surface foliaire des forêts à l'aide de données au sol et aéroportées. / Leaf Area Index (LAI), defined as one half of the total leaf area per unit ground surface area, is a key parameter of vegetation structure for modeling Earth's ecological cycle and its acquisition accuracy always has the need and opportunity for improvement. Active laser scanning provides an opportunity for consistent LAI retrieval at multiple scales because terrestrial laser scanning (TLS) and airborne laser scanning (ALS) have the similar physical mechanism. However, the three-dimensional information of laser scanning is not fully explored in current methods and the traditional theories require adaptation. In this thesis, the path length distribution model is proposed to model the clumping effect, and it is applied to the TLS and ALS data. The method of obtaining the path length distribution of different platforms is studied, and the consistent retrieval model is established. This method is found to improve the individual tree measurement in urban areas and LAI mapping in natural forest, and its results at consistent at different scales. The model is expected to facilitate the consistent retrieval of the forest leaf area index using ground and airborne data.
15

Proposta metodol?gica para o imageamento, caracteriza??o, parametriza??o e gera??o de modelos virtuais de afloramentos

Souza, Anderson de Medeiros 31 January 2013 (has links)
Made available in DSpace on 2015-02-24T19:48:44Z (GMT). No. of bitstreams: 1 AndersonMS_TESE_inicio_pag69.pdf: 4445825 bytes, checksum: 1053632581a0015bab09d4146df22458 (MD5) Previous issue date: 2013-01-31 / Petr?leo Brasileiro SA - PETROBRAS / The aim of this work was to describe the methodological procedures that were mandatory to develop a 3D digital imaging of the external and internal geometry of the analogue outcrops from reservoirs and to build a Virtual Outcrop Model (VOM). The imaging process of the external geometry was acquired by using the Laser Scanner, the Geodesic GPS and the Total Station procedures. On the other hand, the imaging of the internal geometry was evaluated by GPR (Ground Penetrating Radar).The produced VOMs were adapted with much more detailed data with addition of the geological data and the gamma ray and permeability profiles. As a model for the use of the methodological procedures used on this work, the adapted VOM, two outcrops, located at the east part of the Parnaiba Basin, were selected. On the first one, rocks from the aeolian deposit of the Piaui Formation (Neo-carboniferous) and tidal flat deposits from the Pedra de Fogo Formation (Permian), which arises in a large outcrops located between Floriano and Teresina (Piau?), are present. The second area, located at the National Park of Sete Cidades, also at the Piau?, presents rocks from the Cabe?as Formation deposited in fluvial-deltaic systems during the Late Devonian. From the data of the adapted VOMs it was possible to identify lines, surfaces and 3D geometry, and therefore, quantify the geometry of interest. Among the found parameterization values, a table containing the thickness and width, obtained in canal and lobes deposits at the outcrop Pared?o and Biblioteca were the more relevant ones. In fact, this table can be used as an input for stochastic simulation of reservoirs. An example of the direct use of such table and their predicted radargrams was the identification of the bounding surface at the aeolian sites from the Piau? Formation. In spite of such radargrams supply only bi-dimensional data, the acquired lines followed of a mesh profile were used to add a third dimension to the imaging of the internal geometry. This phenomenon appears to be valid for all studied outcrops. As a conclusion, the tool here presented can became a new methodology in which the advantages of the digital imaging acquired from the Laser Scanner (precision, accuracy and speed of acquisition) were combined with the Total Station procedure (precision) using the classical digital photomosaic technique / Neste trabalho s?o apresentados os procedimentos metodol?gicos necess?rios para realizar o imageamento digital 3D da geometria externa e interna de afloramentos an?logos a reservat?rios, e elaborar seus Modelos Virtuais de Afloramentos (MVA). Para imagear a geometria externa foram utilizados o Laser Scanner, o GPS Geod?sico e a Esta??o Total, enquanto que para imagear a geometria interna foi utilizado o GPR. Nos MVA elaborados foram acrescidas ainda as informa??es geol?gicas e as obtidas nas perfilagens com raios gama e de permeabilidade. Como estudo de caso, para exemplificar os procedimentos metodol?gicos propostos, foram escolhidos dois conjuntos de afloramentos na borda leste da Bacia do Parna?ba. Na primeira ?rea ocorrem rochas de origem e?lica da Forma??o Piau? (Neocarbon?fero) e plan?cie de mar? da Forma??o Pedra de Fogo (Permiano), que afloram em um amplo corte de estrada, situado entre Floriano e Teresina (Piau?). A segunda ?rea, situada no Parque Nacional de Sete Cidades, tamb?m no Piau?, envolve rochas da Forma??o Cabe?as depositadas em sistemas fl?vio-deltaicos, durante o Neodevoniano. Com os MVA elaborados foi poss?vel identificar, linhas, superf?cies e geometrias 3D e, assim, quantificar as geometrias de interesse. Dentre as parametriza??es mais relevantes, ressaltam-se a tabela com valores de espessura e largura, obtidas em dep?sitos de canais e em lobos, nos afloramentos Pared?o e Biblioteca. Esta tabela pode ser utilizada como entrada (input) para simula??o estoc?stica de reservat?rios. Um exemplo da aplica??o direta dos radargramas interpretados foi a identifica??o de superf?cies limitantes, em dep?sitos e?licos, da Forma??o Piau?. Apesar dos radargramas oferecerem apenas dados bidimensionais, a aquisi??o de linhas distribu?das segundo uma malha acrescentou a terceira dimens?o ao imageamento das geometrias internas em todos os afloramentos estudados. ? ainda proposta uma nova metodologia que busca conciliar as vantagens obtidas com o imageamento digital com Laser Scanner (precis?o, acur?cia e velocidade de aquisi??o) e a Esta??o Total (precis?o), com o uso cl?ssico de fotomosaicos digitais

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