Participatory GIS: experimentations for a 3D 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 Participatory GIS (PGIS). The purpose of the study is to investigate the extension of PGIS applications, which are quite mature in the traditional bi-dimensional framework, up to the third dimension. More in detail, the system should couple a powerful 3D visualization with an increase of public participation by means of a tool allowing data collecting from mobile devices (e.g. smartphones and tablets). The PGIS application, built using the open source NASA World Wind virtual globe, is focussed on the cultural and tourism heritage of Como city, located in Northern Italy. An authentication mechanism was implemented, which allows users to create and manage customized projects through cartographic mash-ups of Web Map Service (WMS) layers. Saved projects populate a catalogue 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 multimedia data, which come from user field-surveys performed through mobile devices and report POIs (Points Of Interest). Each logged user can then contribute to POIs characterization by adding textual and multimedia information (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.