Three Dimensional Volunteered Geographic Information: A Prototype of a Social Virtual Globe

The dawn of GeoWeb 2.0, the geographic extension of Web 2.0, has opened new possibilities in terms of online dissemination and sharing of geospatial contents, thus laying the foundations for a fruitful development of Volunteered Geographic Information (VGI) systems. The purpose of the study is to investigate the extension of VGI applications, which are quite mature in the traditional bi-dimensional framework, up to the third dimension by means of virtual globes. Inspired by the visionary idea of Digital Earth, virtual globes are changing the way people approach to geographic information on the Web. Unlike the 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. The proposed system should couple a powerful 3D visualization with an increase of public participation thanks to a tool allowing data collecting from mobile devices (e.g. smartphones and tablets). The participative application, built using the open source NASA World Wind virtual globe, is focused on the cultural and tourism heritage of Como city, located in Northern Italy. Users can create and manage customized projects and populate a catalogue of cartographic layers which is available to the entire community. Together with historical maps and the current cartography of the city, the system is also able to manage geo-tagged data, which come from user field-surveys performed through mobile devices in order to report POIs (Points Of Interest). Users can also extend POIs information adding more textual and multimedia contents (e.g. images, audios and videos) directly on the globe. All in all, the resulting application allows users to create and share contributions as it usually happens on social platforms, additionally providing a realistic 3D representation enhancing the expressive power of data.