Development of a New Ground Truth Database for Global Urban Area Mapping from a Gazetteer

We present a practical system for collecting ground truth data needed for global urban area mapping. To collect visually interpreted information effectively, we implemented crowd sourcing, with which the operators collect and send very accurate data generated by visual interpretation through the Internet. The system was constructed with Web Map Service (WMS) and Web Feature Service (WFS), which are standardized scheme of publishing and updating map data over the Internet. Within the system, the conductor and the operators of visual interpretation campaign would save labor and time for transferring data, keeping consistency, and assuring data security. In addition to that, owing to the standardized scheme, the system was flexibly extensible and transferrable to the other purpose. We regard that the system would contribute to improve ground information for global urban area mapping as well as statistical investigation on precision of visual interpretations. 1. INTRODUCTION Global urban area maps, which represent location, area and shape of urban area of the world,