215 research outputs found

    Towards change detection in urban area by SAR interferometry and radargrammetry

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    Change detection in urban area is an active topic in remote sensing. However, well-dealt subject in optical remote sensing, this research topic is still at an early stage and needs deeper investigations and improvement in what concerns SAR and InSAR remote sensing. Due to their weather and daylight-independency, SAR sensors allow an all-time observation of the earth. This is determining in cases where rapid change detection is required after a natural - or technological - disaster. Due to the high resolution that can be achieved, the new generation of space-borne radar sensors opens up new perspectives for analysing buildings in urban areas. Moreover, due to their short revisiting cycle, they give rise to monitoring and change detection applications. In this paper, we present a concept for change detection in urban area at building level, relying only on SAR- and InSAR data. In this approach, interferometric and radargrammetric SAR data are merged in order to detect changes. Here, we present the overall workflow, the test area, the required data as well as first findings on the best-suited stereo-configurations for change detection

    Assessing sustainable urban development trends in a dynamic tourist coastal area using 3D Spatial Indicators

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    In coastal areas, the tourism sector contributes to the local economy, generating income, employment, investments and tax revenues but the rapid urban expansion creates great pressure on local resources and infrastructures, with negative repercussions on the residents’ quality of life, but also compromising the visitor’s experience. These areas face problems such as the formation of meteorological effects known as heat islands, due to the soil sealing, and increased energy demand in the peak season. To evaluate the impact of urban growth spatial pattern and change, three strategic sustainable challenges—urban form, urban energy, and urban outdoor comfort—were selected. The progress towards sustainability was measured and analyzed in a tourist city in the Algarve region, Portugal, for the period 2007–2018, using geographic information. A set of 2D and 3D indicators was derived for the building and block scales. Then, a change assessment based on cluster analysis was performed, and three different trends of sustainable development were identified and mapped. Results allow detecting the urban growth patterns that lead to more sustainable urban areas. The study revealed that a high sustainable development was observed in 12% of the changed blocks in the study area. All indicators suggest that the growth pattern of the coastal area is in line with the studied sustainability dimensions. However, most of the blocks that changed between 2007 and 2018 (82%) followed a low sustainable development. These blocks had the lowest variation in the built volume and density, and consequently the lowest variations in the roof areas with good solar exposition. The urban development also privileged more detached and less compact buildings. This analysis will support the integration of 2D and 3D information into the planning process, assisting smart cities to comply with the sustainable development goals.info:eu-repo/semantics/publishedVersio

    Urban Deformation Monitoring using Persistent Scatterer Interferometry and SAR tomography

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    This book focuses on remote sensing for urban deformation monitoring. In particular, it highlights how deformation monitoring in urban areas can be carried out using Persistent Scatterer Interferometry (PSI) and Synthetic Aperture Radar (SAR) Tomography (TomoSAR). Several contributions show the capabilities of Interferometric SAR (InSAR) and PSI techniques for urban deformation monitoring. Some of them show the advantages of TomoSAR in un-mixing multiple scatterers for urban mapping and monitoring. This book is dedicated to the technical and scientific community interested in urban applications. It is useful for choosing the appropriate technique and gaining an assessment of the expected performance. The book will also be useful to researchers, as it provides information on the state-of-the-art and new trends in this fiel

    Remote Sensing and Geosciences for Archaeology

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    This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications

    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

    Fusion of high spatial resolution multispectral & object height data for urban environmental monitoring: methods & applications

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    High spatial resolution (HSR) multispectral and object height data are becoming increasingly available in the urbanized regions of the world. The synergistic utilization of these data sources holds a large potential for the fine-scale characterization of a city because they are of high descriptive power and non-redundant. However, despite this promising development, detailed and area-wide maps of important settlement parameters, like land cover (LC), urban site characteristics (USCs), and urban structure types (USTs), are still lacking in many municipalities. One reason for this observation is the methodological challenge of turning the wealth of geospatial data into reliable thematic information. Accordingly, there is a strong need for accurate and transferable software solutions being able to produce some of the key data sets for human settlement monitoring from HSR multispectral and object height data. The present work aims at addressing this need. The overall goal of the dissertation was to develop methods for the fusion of HSR multispectral and object height data as well as to showcase their utility in the context of different urban environmental mapping and monitoring applications. It therefore intended to make both a technical and an applied contribution to the field of urban remote sensing. Particular emphasis was put on mapping urban LC, USCs, and USTs, as well as the usage of USCs to study urban land surface temperature (LST) and the surface urban heat island (UHI) effect. These settlement parameters were chosen because they are thematically connected, difficult to obtain from other data sources, and of high relevance for urban planning. To meet the above goal, a comprehensive literature review was conducted in advance. The review helped identifying current deficits within the chosen research fields and led to the formulation of specific thesis objectives. The latter determined the practical agenda of this work, comprising an overall number of four studies.Die Verfügbarkeit räumlich hochaufgelöster Multispektral- und Objekthöhendaten nimmt für die urbanen Gebiete der Erde stetig zu. Die synergetische Verknüpfung solcher Daten birgt ein großes Potential zur genauen Beschreibung von Städten, da diese Daten einen hohen Informationsgehalt aufweisen und redundanzfrei sind. Trotz dieser positiven Entwicklung fehlt es in vielen Städten an detaillierten Karten, welche Aufschluss über planungsrelevante Siedlungsparameter geben. Ein Grund für diese Beobachtung ist die methodische Herausforderung, die Fülle an zugänglichen Geodaten in verlässliche thematische Informationen zu überführen. Demzufolge besteht ein großer Bedarf an akkuraten und übertragbaren Auswertungsverfahren, welche sich das Synergiepotential räumlich hochaufgelöster Multispektral- und Objekthöhendaten für ein verbessertes Stadtmonitoring zunutze machen. Die vorliegende Arbeit zielt darauf ab, diesen Bedarf zu decken. Das übergeordnete Ziel der Dissertation war, Methoden zur Fusion räumlich hochaufgelöster Multispektral- und Objekthöhendaten zu entwickeln und deren Nutzen im Rahmen stadtumweltbezogener Fragestellungen zu demonstrieren. Folglich sollte die Arbeit einen technischen und einen angewandten Beitrag auf dem Gebiet der urbanen Fernerkundung leisten. Das Hauptaugenmerk lag auf der genauen und robusten Kartierung der Landbedeckung und Stadtstruktur. Darüber hinaus wurden verschiedene urbane Bewertungsindikatoren extrahiert und zu einem neuen Dichtemaß verknüpft. Die abgeleiteten Karten und Indikatoren kamen im Zuge einer abschließenden Analyse zum Einsatz, welche sich mit den Ursprüngen städtischer Wärmeinseln befasste. Um das obige Ziel zu erreichen, wurde im Vorfeld eine umfangreiche Literaturrecherche vorgenommen. Diese ermöglichte die Identifikation derzeitiger Forschungsdefizite und führte zur Formulierung spezifischer Arbeitsziele. Nach den Zielen richtete sich der praktische Teil der kumulativen Dissertation, welcher insgesamt vier Studien umfasste

    L'AIS : une donnée pour l'analyse des activités en mer

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    4 pages, session "Mer et littoral"International audienceCette contribution présente des éléments méthodologiques pour la description des activités humaines en mer dans une perspective d'aide à la gestion. Différentes procédures, combinant l'exploitation de bases de données spatio-temporelles issue de données AIS archivées à des analyses spatiales au sein d'un SIG, sont testées afin de caractériser le transport maritime en Mer d'Iroise (Bretagne, France) sur les plans spatiaux, temporels et quantitatifs au cours d'une année

    The Post-Screen Through Virtual Reality, Holograms and Light Projections

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    Screens are ubiquitous today. They display information; present image worlds; are portable; connect to mobile networks; mesmerize. However, contemporary screen media also seek to eliminate the presence of the screen and the visibilities of its boundaries. As what is image becomes increasingly indistinguishable against the viewer’s actual surroundings, this unsettling prompts re-examination about not only what is the screen, but also how the screen demarcates and what it stands for in relation to our understanding of our realities in, outside and against images. Through case studies drawn from three media technologies – Virtual Reality; holograms; and light projections – this book develops new theories of the surfaces on and spaces in which images are displayed today, interrogating critical lines between art and life; virtuality and actuality; truth and lies. What we have today is not just the contestation of the real against illusion or the unreal, but the disappearance itself of difference and a gluttony of the unreal which both connect up to current politics of distorted truth values and corrupted terms of information. The Post-Screen Through Virtual Reality, Holograms and Light Projections: Where Screen Boundaries Lie is thus about not only where the image’s borders and demarcations are established, but also the screen boundary as the instrumentation of today’s intense virtualizations that do not tell the truth. In all this, a new imagination for images emerges, with a new space for cultures of presence and absence, definitions of object and representation, and understandings of dis- and re-placement – the post-screen

    Urban Informatics

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    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity

    Urban Informatics

    Get PDF
    This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity
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