165 research outputs found

    A methodology to produce geographical information for land planning using very-high resolution images

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    Actualmente, os municípios são obrigados a produzir, no âmbito da elaboração dos instrumentos de gestão territorial, cartografia homologada pela autoridade nacional. O Plano Director Municipal (PDM) tem um período de vigência de 10 anos. Porém, no que diz respeito à cartografia para estes planos, principalmente em municípios onde a pressão urbanística é elevada, esta periodicidade não é compatível com a dinâmica de alteração de uso do solo. Emerge assim, a necessidade de um processo de produção mais eficaz, que permita a obtenção de uma nova cartografia de base e temática mais frequentemente. Em Portugal recorre-se à fotografia aérea como informação de base para a produção de cartografia de grande escala. Por um lado, embora este suporte de informação resulte em mapas bastante rigorosos e detalhados, a sua produção têm custos muito elevados e consomem muito tempo. As imagens de satélite de muito alta-resolução espacial podem constituir uma alternativa, mas sem substituir as fotografias aéreas na produção de cartografia temática, a grande escala. O tema da tese trata assim da satisfação das necessidades municipais em informação geográfica actualizada. Para melhor conhecer o valor e utilidade desta informação, realizou-se um inquérito aos municípios Portugueses. Este passo foi essencial para avaliar a pertinência e a utilidade da introdução de imagens de satélite de muito alta-resolução espacial na cadeia de procedimentos de actualização de alguns temas, quer na cartografia de base quer na cartografia temática. A abordagem proposta para solução do problema identificado baseia-se no uso de imagens de satélite e outros dados digitais em ambiente de Sistemas de Informação Geográfica. A experimentação teve como objectivo a extracção automática de elementos de interesse municipal a partir de imagens de muito alta-resolução espacial (fotografias aéreas ortorectificadas, imagem QuickBird, e imagem IKONOS), bem como de dados altimétricos (dados LiDAR). Avaliaram-se as potencialidades da informação geográfica extraídas das imagens para fins cartográficos e analíticos. Desenvolveram-se quatro casos de estudo que reflectem diferentes usos para os dados geográficos a nível municipal, e que traduzem aplicações com exigências diferentes. No primeiro caso de estudo, propõe-se uma metodologia para actualização periódica de cartografia a grande escala, que faz uso de fotografias aéreas vi ortorectificadas na área da Alta de Lisboa. Esta é uma aplicação quantitativa onde as qualidades posicionais e geométricas dos elementos extraídos são mais exigentes. No segundo caso de estudo, criou-se um sistema de alarme para áreas potencialmente alteradas, com recurso a uma imagem QuickBird e dados LiDAR, no Bairro da Madre de Deus, com objectivo de auxiliar a actualização de cartografia de grande escala. No terceiro caso de estudo avaliou-se o potencial solar de topos de edifícios nas Avenidas Novas, com recurso a dados LiDAR. No quarto caso de estudo, propõe-se uma série de indicadores municipais de monitorização territorial, obtidos pelo processamento de uma imagem IKONOS que cobre toda a área do concelho de Lisboa. Esta é uma aplicação com fins analíticos onde a qualidade temática da extracção é mais relevante.Currently, the Portuguese municipalities are required to produce homologated cartography, under the Territorial Management Instruments framework. The Municipal Master Plan (PDM) has to be revised every 10 years, as well as the topographic and thematic maps that describe the municipal territory. However, this period is inadequate for representing counties where urban pressure is high, and where the changes in the land use are very dynamic. Consequently, emerges the need for a more efficient mapping process, allowing obtaining recent geographic information more often. Several countries, including Portugal, continue to use aerial photography for large-scale mapping. Although this data enables highly accurate maps, its acquisition and visual interpretation are very costly and time consuming. Very-High Resolution (VHR) satellite imagery can be an alternative data source, without replacing the aerial images, for producing large-scale thematic cartography. The focus of the thesis is the demand for updated geographic information in the land planning process. To better understand the value and usefulness of this information, a survey of all Portuguese municipalities was carried out. This step was essential for assessing the relevance and usefulness of the introduction of VHR satellite imagery in the chain of procedures for updating land information. The proposed methodology is based on the use of VHR satellite imagery, and other digital data, in a Geographic Information Systems (GIS) environment. Different algorithms for feature extraction that take into account the variation in texture, color and shape of objects in the image, were tested. The trials aimed for automatic extraction of features of municipal interest, based on aerial and satellite high-resolution (orthophotos, QuickBird and IKONOS imagery) as well as elevation data (altimetric information and LiDAR data). To evaluate the potential of geographic information extracted from VHR images, two areas of application were identified: mapping and analytical purposes. Four case studies that reflect different uses of geographic data at the municipal level, with different accuracy requirements, were considered. The first case study presents a methodology for periodic updating of large-scale maps based on orthophotos, in the area of Alta de Lisboa. This is a situation where the positional and geometric accuracy of the extracted information are more demanding, since technical mapping standards must be complied. In the second case study, an alarm system that indicates the location of potential changes in building areas, using a QuickBird image and LiDAR data, was developed for the area of Bairro da Madre de Deus. The goal of the system is to assist the updating of large scale mapping, providing a layer that can be used by the municipal technicians as the basis for manual editing. In the third case study, the analysis of the most suitable roof-tops for installing solar systems, using LiDAR data, was performed in the area of Avenidas Novas. A set of urban environment indicators obtained from VHR imagery is presented. The concept is demonstrated for the entire city of Lisbon, through IKONOS imagery processing. In this analytical application, the positional quality issue of extraction is less relevant.GEOSAT – Methodologies to extract large scale GEOgraphical information from very high resolution SATellite images (PTDC/GEO/64826/2006), e-GEO – Centro de Estudos de Geografia e Planeamento Regional, da Faculdade de Ciências Sociais e Humanas, no quadro do Grupo de Investigação Modelação Geográfica, Cidades e Ordenamento do Territóri

    Development of spatial inspection methods to support building inspections and compliance

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    The use of spatial information is important to performing building inspections and determining compliance according to regulations. This research identifies the current issues relating to lack of access to spatial information, poor integration of data sources and lack of quality information in the inspection process. A spatially-enabled framework to support building inspections was designed and proposed. A prototype was developed for a case study in a district of Riyadh, Saudi Arabia, and used to evaluate the framework. The prototype utilised a range of data and imagery of various quality to identify and compare instances of violations with calculated certainties. Results indicate substantial benefits to building inspectors for integrating a spatially-enabled process into a building inspection workflow

    Earth Resources, A Continuing Bibliography with Indexes

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    This bibliography lists 460 reports, articles and other documents introduced into the NASA scientific and technical information system between July 1 and September 30, 1984. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economical analysis

    Geomatics in support of the Common Agriculture Policy

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    The 2009 Annual Conference was the 15th organised by GeoCAP action of the Joint Research Centre in ISPRA. It was jointly organised with the Italian Agenzia per le erogazioni in agricoltura (AGEA, coordinating organism of the Italian agricultural paying agencies). The Conference covered the 2009 Control with Remote sensing campaign activities and ortho-imagery use in all the CAP management and control procedures. There has been a specific focus on the Land Parcel Identification Systems quality assessment process. The conference was structured over three days ¿ 18th to 20th November. The first day was mainly dedicated to future Common Agriculture Policy perspectives and futures challenges in Agriculture. The second was shared in technical parallel sessions addressing topics like: LPIS Quality Assurance and geodatabases features; new sensors, new software, and their use within the CAP; and Good Agriculture and Environmental Conditions (GAEC) control methods and implementing measures. The last day was dedicated to the review of the 2009 CwRS campaign and the preparation of the 2010 one. The presentations were made available on line, and this publication represents the best presentations judged worthy of inclusion in a conference proceedings aimed at recording the state of the art of technology and practice of that time.JRC.DG.G.3-Monitoring agricultural resource

    GEOBIA 2016 : Solutions and Synergies., 14-16 September 2016, University of Twente Faculty of Geo-Information and Earth Observation (ITC): open access e-book

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    Extraction of Urban Environmental Quality Indicators using LiDAR-Based Digital Surface Models

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    The visualization of specific 3-D urban scenes can be done calling upon different techniques, from those more traditional, such as photogrammetry, to the most advanced ones, such as laser scanning that uses different techniques and algorithms of selection and modelling of 3-D point clouds. The use and utility of this kind of data for the study of urban development remain however debatable. Indeed, indicators for urban development and durability are highly necessary and the best methodology to build them is largely open. This thesis anticipates the use of 2-D and 3-D models and data for the environmental analysis of cities, aiming to provide useful tools for urban planning and design. According to end-users requirements, the extraction of urban environmental quality (UEQ) indicators from 2-D and 3-D information using innovative methods is proposed and implemented, which is based on recent research on computational algorithms for the analysis, evaluation, management and design of the urban space. Moreover, results that can be obtained with different data sources and aggregation methods are compared. In particular, the main advantages of urban models generated from LiDAR data are highlighted. In consequence, an iterative process is proposed, involving professionals of various fields, aiming at improving the utility of those indicators for the support of applied decision activities related to the sustainable development of cities. This process is sub-divided in three correlated steps: A preliminary inquiry concerning the user requirements for the implementation of a 3-D project of the State/City of Geneva was launched. Based on the obtained replies, several potential applications related to both the definition and extraction of urban indicators were identified, and also, end-users were classified into 6 different domains: 1– architecture, urbanism and territory planning; 2– urban traffic (motor vehicles, trains and airplanes); 3– environment and energy; 4– pedestrian and cyclist mobility; 5– security and emergency situations management; 6– underground information; Based on point 1. and according to the assessment of the specific needs among each of these domains, several interviews were carried out in which 25 end-users decided to focus on UEQ indicators considering three main stakes: 1– assessment of the morphological properties of the urban texture; 2– exploration of the solar potential on the urban fabric; 3– estimation of the energy demand on the urban fabric. Many empirical case-studies are emphasized, mostly for the city of Geneva, and also for the cities of Lausanne and Florence. These indicators are extracted from the segmentation of planar roof areas using classified LiDAR point clouds and the use of image processing techniques based on Digital Elevation Models (DEM) and Digital Height Models (DHM), defined in this thesis as 2.5-Digital Urban Surface Models (2.5-DUSM) and normalized 2.5-Digital Urban Surface Models (n2.5-DUSM) respectively. These models are constructed in a step by step basis, using LiDAR and 2-D and 3-D vector data, thus applying different methods of interpolation and enhancement, whose accuracy is also evaluated on a statistical basis; Finally, an inquiry on how the same group of 25 end-users mentioned in point 1. perceives and interprets the different exploratory 2-D and 3-D geo-visualizations proposed for some of the UEQ indicators is undertaken, evaluating their utility according to the requirements previously defined

    Extracção automática de dados georreferenciados a partir dos planos cadastrais portugueses

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    Tese dout., Engenharia Electrónica e Computação, Universidade do Algarve, 2009Image recognition algorithms are used to extract information from digitized images automatically. Systems designed to convert paper documents into meaningful vectorial representations are numerous nowadays, and have been constantly improved over the two last decades. However, none of these systems seems to be able to provide satisfying results when it comes to convert complex documents such as technical drawings, usually semantic of the problem is not considered and post-processing costs remain high. This dissertation presents a set of techniques that greatly simplifies the automatic extraction of cadastral entities from the portuguese cadastral maps. The validity of the approach is illustrated designing a prototype system, joining all recognition algorithms and validating all information.Fundação para a Ciência e Tecnologia (FCT

    Literature review of the remote sensing of natural resources

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    Abstracts of 596 documents related to remote sensors or the remote sensing of natural resources by satellite, aircraft, or ground-based stations are presented. Topics covered include general theory, geology and hydrology, agriculture and forestry, marine sciences, urban land use, and instrumentation. Recent documents not yet cited in any of the seven information sources used for the compilation are summarized. An author/key word index is provided
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