International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-4/W2, 2013 ISPRS WebMGS 2013 & DMGIS 2013, 11 – 12 November 2013, Xuzhou, Jiangsu, China Topics: Global Spatial Grid & Cloud-based Services THE POWER OF VIRTUAL GLOBES FOR VALORISING CULTURAL HERITAGE AND ENABLING SUSTAINABLE TOURISM: NASA WORLD WIND APPLICATIONS M. A. Brovelli a , P. Hogan b , M. Minghini a , G. Zamboni a a Politecnico di Milano, DICA, Laboratorio di Geomatica, Como Campus, via Valleggio 11, 22100 Como, Italy - [email protected], [email protected], [email protected] b NASA Ames Research Center, M/S 244-14, Moffett Field, CA USA - [email protected] Commission IV, Working Group IV/5 KEY WORDS: Cultural Heritage, GIS, Three-dimensional, Virtual Globe, Web based ABSTRACT: Inspired by the visionary idea of Digital Earth, as well as from the tremendous improvements in geo-technologies, use of virtual globes has been changing the way people approach to geographic information on the Web. Unlike the traditional 2D-visualization typical of Geographic Information Systems (GIS), virtual globes offer multi-dimensional, fully-realistic content visualization which allows for a much richer user experience. This research investigates the potential for using virtual globes to foster tourism and enhance cultural heritage. The paper first outlines the state of the art for existing virtual globes, pointing out some possible categorizations according to license type, platform-dependence, application type, default layers, functionalities and freedom of customization. Based on this analysis, the NASA World Wind virtual globe is the preferred tool for promoting tourism and cultural heritage. This is because its open source nature allows unlimited customization (in terms of both data and functionalities), and its Java core supports platform-independence. Relevant tourism-oriented World Wind-based applications, dealing with both the Web promotion of historical cartography and the setup of a participatory Web platform exploiting crowd-sourced data, are described. Finally, the paper presents a project focusing on the promotion of the Via Regina area (crossing the border between Italy and Switzerland) through an ad hoc World Wind customization. World Wind can thus be considered an ideal virtual globe for tourism applications, as it can be shaped to increase awareness of cultural history and, in turn, enhance touristic experience. 1. INTRODUCTION model of the Earth, with the freedom of exploration and the ability to visualize huge amounts of data. The use of the Web as a dissemination medium for maps can be The concept of Digital Earth was proposed by Al Gore (1999), regarded as a major advancement in cartography and opens who described the possibility for citizens to interact with a many new opportunities, such as real-time maps, cheaper computer-generated multidimensional spinning virtual globe dissemination, more frequent and cheaper updates of data and and to access vast amounts of environmental and cultural software, personalized map content, distributed data sources information. The idea was to help citizens understand the Earth and sharing of geographic information. It also encounters many and human activities as part of its history. A Digital Earth challenges due to technical restrictions (low display resolution greatly helps this citizen interaction. The combination of the and limited bandwidth, in particular with mobile computing Web and access to geographic data has made possible the devices, many of which are physically small and use slow development of powerful virtual globes which now provide this wireless Internet connections), copyright and security issues, Digital Earth. The terms Digital Earth and virtual globe are reliability issues and technical complexity. While the first Web usually considered synonyms, although Digital Earth points maps were primarily static, today’s Web maps can be fully most clearly to the unequivocally multiple experiences and interactive and integrate multiple media. This means that both knowledge we have, and continue to make, of the world, while Web mapping and Web cartography also have to deal with virtual globe appears to be the more viable term for discussions interactivity, usability and multimedia issues (Neumann, 2008). of the applications’ software environment (Harvey, 2009). For several years geographic information has been represented Virtual globes can be considered as multi-purpose and multi- on the computer in a bi-dimensional way, as natural evolution dimensional, not only 3D but also 4D if the temporal dimension of the computerization of the classic 2D paper maps. With the is also considered. This geographic environment can represent growth of the 3D computer graphics and the spread of high- any geo-localizable data in a nearly infinite range of scales, and performance hardware (processing power, storage capacities, where user is able to move freely around the globe dynamically 3D-enabled video cards, etc.) the geospatial viewer started to changing the point of view and interacting with the information show data in the three-dimensional aspects of their virtual represented on the surface (Elvidge and Tuttle, 2008). Using a geographic features. The first 3D geographic viewers were virtual globe it is possible for instance to show a spatial mainly developed by scientific and technical institutes for distribution of an environmental variable (e.g. temperature, specific research purposes and provided 3D visualization of pressure and concentration of a pollutant) around the entire data usually restricted to a limited area of interest. Earth, and zoom into the city streets to show the detailed Nowadays, so-called virtual globes are a highly advanced structure of an urban setting (e.g. position of environmental evolution of these viewers, providing the ability to render monitoring stations, 3D representation of polluting factories and terrain, imagery and vector datasets over a whole 3D digital related technological networks). This contribution has been peer-reviewed. doi:10.5194/isprsarchives-XL-4-W2-115-2013 115 International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-4/W2, 2013 ISPRS WebMGS 2013 & DMGIS 2013, 11 – 12 November 2013, Xuzhou, Jiangsu, China Topics: Global Spatial Grid & Cloud-based Services Virtual globes have been emerging in recent years thanks to Virtual globes are available with different capabilities and their context capability and, at the same time, their ease of use characteristics: they differ from each other according to the which provides good user experience. In particular, they are philosophy of development, the technology used, the features becoming more and more important due to their intuitiveness of implemented, the spatial coverage, and the typology of user. use, the faithful correspondence of information to the reality These products use different data sources for the layers represented and their multi-disciplinary relevance. represented on the globe (digital elevation models, satellite and The growth of increasingly accurate and detailed geographic aerial imagery, topographic maps, vector layers, etc.). This data such as aerial and satellite images, digital elevation models means they also differ for the temporal accuracy, visual quality and topographic maps, the increased Internet accessibility to of represented geographical features, and for supported formats these data provided by map-servers with standard protocols (by used to represent grid, raster and vector data. ISO and OGC) and the easiness of the virtual globes to be In this section it is not the authors’ intention to make an customized through the direct mapping of any geographically accurate census of all the existing virtual globes, but only localized phenomenon (e.g. physical, social and environmental) briefly recall the main properties to be evaluated in order to have not only increased the popular use of these technologies, select the most appropriate virtual globes for the given specific but have also offered great opportunities to improve geographic needs. The first main classification that distinguishes virtual representations and scientific analysis. globes is the license type. Some of them are available as free The possibility of simultaneously geo-locating different kinds of and open source software (e.g. NASA World Wind, information within a single 3D virtual environment opens many ossimPlanet, osgEarth, Marble), while others are “closed” (code fields of use for these tools in those disciplines that depend on not available for the public) and released with proprietary geographic data (i.e. education, archaeology, sociology, urban licenses. Some of the latter require purchase of a license (e.g. and environmental planning, etc.). Until not long ago, this data ESRI ArcGlobe, SkylineGlobe, CitySurf Globe) while still could only be textually represented using highly technical and others are available both with a freeware license (e.g. Google specific tools such as Geographic Information Systems (GIS). Earth free) or a paid license depending on the capabilities Virtual globes are an excellent tool that extends the expressive required (e.g. Google Earth Pro, Google Earth Enterprise). power through a conceptual representation of GIS data in a The second main feature that can be used to classify virtual more realistic and intuitive medium. At the same time, ease of globes is the platform required to run