554 research outputs found

    Horizontal accuracy assessment of very high resolution Google Earth images in the city of Rome, Italy

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    Google Earth (GE) has recently become the focus of increasing interest and popularity among available online virtual globes used in scientific research projects, due to the free and easily accessed satellite imagery provided with global coverage. Nevertheless, the uses of this service raises several research questions on the quality and uncertainty of spatial data (e.g. positional accuracy, precision, consistency), with implications for potential uses like data collection and validation. This paper aims to analyze the horizontal accuracy of very high resolution (VHR) GE images in the city of Rome (Italy) for the years 2007, 2011, and 2013. The evaluation was conducted by using both Global Positioning System ground truth data and cadastral photogrammetric vertex as independent check points. The validation process includes the comparison of histograms, graph plots, tests of normality, azimuthal direction errors, and the calculation of standard statistical parameters. The results show that GE VHR imageries of Rome have an overall positional accuracy close to 1 m, sufficient for deriving ground truth samples, measurements, and large-scale planimetric maps

    Crowdsourcing indicators for cultural ecosystem services : a geographically weighted approach for mountain landscapes

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    This study was partially supported by the OpenNESS project funded from the European Union's Seventh Programme for research; technological development and demonstration under grant agreement n° 308428.Integrating cultural dimensions into the ecosystem service framework is essential for appraising non-material benefits stemming from different human-environment interactions. This study investigates how the actual provision of cultural services is distributed across the landscape according to spatially varying relationships. The final aim was to analyse how landscape settings are associated to people’s preferences and perceptions related to cultural ecosystem services in mountain landscapes. We demonstrated a spatially explicit method based on geo-tagged images from popular social media to assess revealed preferences. A spatially weighted regression showed that specific variables correspond to prominent drivers of cultural ecosystem services at the local scale. The results of this explanatory approach can be used to integrate the cultural service dimension into land planning by taking into account specific benefiting areas and by setting priorities on the ecosystems and landscape characteristics which affect the service supply. We finally concluded that the use of crowdsourced data allows identifying spatial patterns of cultural ecosystem service preferences and their association with landscape settings.PostprintPeer reviewe

    Geographic Information Systems and Science

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    Geographic information science (GISc) has established itself as a collaborative information-processing scheme that is increasing in popularity. Yet, this interdisciplinary and/or transdisciplinary system is still somewhat misunderstood. This book talks about some of the GISc domains encompassing students, researchers, and common users. Chapters focus on important aspects of GISc, keeping in mind the processing capability of GIS along with the mathematics and formulae involved in getting each solution. The book has one introductory and eight main chapters divided into five sections. The first section is more general and focuses on what GISc is and its relation to GIS and Geography, the second is about location analytics and modeling, the third on remote sensing data analysis, the fourth on big data and augmented reality, and, finally, the fifth looks over volunteered geographic information.info:eu-repo/semantics/publishedVersio

    Multi-environment Georeferencing of RGB-D Panoramic Images from Portable Mobile Mapping – a Perspective for Infrastructure Management

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    Hochaufgelöste, genau georeferenzierte RGB-D-Bilder sind die Grundlage für 3D-Bildräume bzw. 3D Street-View-Webdienste, welche bereits kommerziell für das Infrastrukturmanagement eingesetzt werden. MMS ermöglichen eine schnelle und effiziente Datenerfassung von Infrastrukturen. Die meisten im Aussenraum eingesetzten MMS beruhen auf direkter Georeferenzierung. Diese ermöglicht in offenen Bereichen absolute Genauigkeiten im Zentimeterbereich. Bei GNSS-Abschattung fällt die Genauigkeit der direkten Georeferenzierung jedoch schnell in den Dezimeter- oder sogar in den Meterbereich. In Innenräumen eingesetzte MMS basieren hingegen meist auf SLAM. Die meisten SLAM-Algorithmen wurden jedoch für niedrige Latenzzeiten und für Echtzeitleistung optimiert und nehmen daher Abstriche bei der Genauigkeit, der Kartenqualität und der maximalen Ausdehnung in Kauf. Das Ziel dieser Arbeit ist, hochaufgelöste RGB-D-Bilder in verschiedenen Umgebungen zu erfassen und diese genau und zuverlässig zu georeferenzieren. Für die Datenerfassung wurde ein leistungsstarkes, bildfokussiertes und rucksackgetragenes MMS entwickelt. Dieses besteht aus einer Mehrkopf-Panoramakamera, zwei Multi-Beam LiDAR-Scannern und einer GNSS- und IMU-kombinierten Navigationseinheit der taktischen Leistungsklasse. Alle Sensoren sind präzise synchronisiert und ermöglichen Zugriff auf die Rohdaten. Das Gesamtsystem wurde in Testfeldern mit bündelblockbasierten sowie merkmalsbasierten Methoden kalibriert, was eine Voraussetzung für die Integration kinematischer Sensordaten darstellt. Für eine genaue und zuverlässige Georeferenzierung in verschiedenen Umgebungen wurde ein mehrstufiger Georeferenzierungsansatz entwickelt, welcher verschiedene Sensordaten und Georeferenzierungsmethoden vereint. Direkte und LiDAR SLAM-basierte Georeferenzierung liefern Initialposen für die nachträgliche bildbasierte Georeferenzierung mittels erweiterter SfM-Pipeline. Die bildbasierte Georeferenzierung führt zu einer präzisen aber spärlichen Trajektorie, welche sich für die Georeferenzierung von Bildern eignet. Um eine dichte Trajektorie zu erhalten, die sich auch für die Georeferenzierung von LiDAR-Daten eignet, wurde die direkte Georeferenzierung mit Posen der bildbasierten Georeferenzierung gestützt. Umfassende Leistungsuntersuchungen in drei weiträumigen anspruchsvollen Testgebieten zeigen die Möglichkeiten und Grenzen unseres Georeferenzierungsansatzes. Die drei Testgebiete im Stadtzentrum, im Wald und im Gebäude repräsentieren reale Bedingungen mit eingeschränktem GNSS-Empfang, schlechter Beleuchtung, sich bewegenden Objekten und sich wiederholenden geometrischen Mustern. Die bildbasierte Georeferenzierung erzielte die besten Genauigkeiten, wobei die mittlere Präzision im Bereich von 5 mm bis 7 mm lag. Die absolute Genauigkeit betrug 85 mm bis 131 mm, was einer Verbesserung um Faktor 2 bis 7 gegenüber der direkten und LiDAR SLAM-basierten Georeferenzierung entspricht. Die direkte Georeferenzierung mit CUPT-Stützung von Bildposen der bildbasierten Georeferenzierung, führte zu einer leicht verschlechterten mittleren Präzision im Bereich von 13 mm bis 16 mm, wobei sich die mittlere absolute Genauigkeit nicht signifikant von der bildbasierten Georeferenzierung unterschied. Die in herausfordernden Umgebungen erzielten Genauigkeiten bestätigen frühere Untersuchungen unter optimalen Bedingungen und liegen in derselben Grössenordnung wie die Resultate anderer Forschungsgruppen. Sie können für die Erstellung von Street-View-Services in herausfordernden Umgebungen für das Infrastrukturmanagement verwendet werden. Genau und zuverlässig georeferenzierte RGB-D-Bilder haben ein grosses Potenzial für zukünftige visuelle Lokalisierungs- und AR-Anwendungen

    PROPOSAL FOR A LANDSCAPE EVALUATION SYSTEM

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    This paper describes a system, currently being designed, for both perceptual analysis and aesthetic evaluation of a landscape. The choice of this topic is motivated by the fact that systems related to landscape visibility (e.g. Geographical Information Systems (GIS) for visual impact assessment) are not fully satisfactory when it comes to assessing the aesthetic appearance. They mainly analyse geometric aspects, such as the width of visual basins or the interference of visual trajectories, which can be expressed by objective and comparable parameters. Instead, for effective landscape knowledge and protection, it is important to consider other factors that cannot be easily measured, namely the quality of human perception, i.e. the aesthetic judgements that people can express about a landscape. Based on these considerations, a system has been designed in order to analyse the elements that can influence the aesthetic judgement of a landscape and therefore simulate the more probable aesthetic judgement. Unlike GIS generally works, this system does not use maps, but perspective views obtained by means of vehicle-mounted cameras, as in mobile mapping technology (MMT). Research into the system described below consisted of two parts: firstly how to form the database on which the system is based and secondly how to use the system. The database contains a large number of views analysed in terms of geometric, qualitative, thematic, topological and gestalt aspects; the results of these analyses are recorded in tables and improved through a parameter expressing an aesthetic judgement. This aesthetic judgement is obtained by processing the responses of a group of participants to a sociological and/or neurological survey (i.e. Functional Magnetic Resonance Imaging). In the operational phase, a new view will be evaluated by comparison with the views stored in the database The new view will be given a judgment, obtained by processing the judgments of the most similar views. The idea of this system applies both to the assessment of a single view and to the evaluation of territorial contexts. Once this system has been defined, it will have to be tested through practical application

    Geoinformatics for the conservation and promotion of cultural heritage in support of the UN Sustainable Development Goals

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    Cultural Heritage (CH) is recognised as being of historical, social, and anthropological value and is considered as an enabler of sustainable development. As a result, it is included in the United Nations' Sustainable Development Goals (SDGs) 11 and 8. SDG 11.4 emphasises the protection and safeguarding of heritage, and SDG 8.9 aims to promote sustainable tourism that creates jobs and promotes local culture and products. This paper briefly reviews the geoinformatics technologies of photogrammetry, remote sensing, and spatial information science and their application to CH. Detailed aspects of CH-related SDGs, comprising protection and safeguarding, as well as the promotion of sustainable tourism are outlined. Contributions of geoinformatics technologies to each of these aspects are then identified and analysed. Case studies in both developing and developed countries, supported by funding directed at the UN SDGs, are presented to illustrate the challenges and opportunities of geoinformatics to enhance CH protection and to promote sustainable tourism. The potential and impact of geoinformatics for the measurement of official SDG indicators, as well as UNESCO's Culture for Development Indicators, are discussed. Based on analysis of the review and the presented case studies, it is concluded that the contribution of geoinformatics to the achievement of CH SDGs is necessary, significant and evident. Moreover, following the UNESCO initiative to introduce CH into the sustainable development agenda and related ICOMOS action plan, the concept of Sustainable Cultural Heritage is defined, reflecting the significance of CH to the United Nations' ambition to "transform our world"

    From Knowledge to Land-Use Planning: Local Resilient Experience in the Territory of the Municipality of Mappano

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    The chapter illustrates the result of the analysis on the municipality of Mappano, located in northern Turin (Italy). The studies were carried out as part of the collaboration between the Municipality of Mappano and the Inter-University Department of Territorial and Urban Studies and Planning (DIST) of the Politecnico di Torino, for the preparation of the first Municipal Urban Plan. The main goal was to contribute to this local planning tool by introducing innovative analyses, descriptions and elaborations which were useful in structuring planning choices. In particular, various data sources were systematized, integrated and coordinated to represent the territory from the point of view of both enviro

    SkiVis: Visual Exploration and Route Planning in Ski Resorts

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    Optimal ski route selection is a challenge based on a multitude of factors, such as the steepness, compass direction, or crowdedness. The personal preferences of every skier towards these factors require individual adaptations, which aggravate this task. Current approaches within this domain do not combine automated routing capabilities with user preferences, missing out on the possibility of integrating domain knowledge in the analysis process. We introduce SkiVis, a visual analytics application to interactively explore ski slopes and provide routing recommendations based on user preferences. In collaboration with ski guides and enthusiasts, we elicited requirements and guidelines for such an application and propose different workflows depending on the skiers' familiarity with the resort. In a case study on the resort of Ski Arlberg, we illustrate how to leverage volunteered geographic information to enable a numerical comparison between slopes. We evaluated our approach through a pair-analytics study and demonstrate how it supports skiers in discovering relevant and preference-based ski routes. Besides the tasks investigated in the study, we derive additional use cases from the interviews that showcase the further potential of SkiVis, and contribute directions for further research opportunities.Comment: 11 pages, 10 figure

    GIS-based recreation experience mapping:development, validation and implementation

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    Exploring the Visual Landscape: Advances in Physiognomic Landscape Research in the Netherlands

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    Exploring the Visual Landscape is about the combination of landscape research and planning, visual perception and Geographic Information Science. It showcases possible ways of getting a grip on themes like: landscape openness, cluttering of the rural landscape, high-rise buildings in relation to cityscape, historic landscapes and motorway panoramas. It offers clues for visual landscape assessment of spaces in cities, parks and rural areas. In that respect, it extends the long tradition in the Netherlands on physiognomic landscape research and shows the state of the art at this moment. Exploring the Visual Landscape offers important clues for theory, methodology and application in research and development of landscapes all over the world, from a specifically Dutch academic context. It provides a wide range of insights into the psychological background of landscape perception, the technical considerations of geomatics and methodology in landscape architecture, urban planning and design. Furthermore, there are some experiences worthwhile considering, which demonstrate how this research can be applied in the practice of landscape policy making
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