@proceedings {78,
	title = {Crowd-Sourcing GIS for Global Urban Area Mapping},
	year = {2012},
	month = {2012},
	pages = {A4-2},
	address = {Pattaya, Thailand},
	abstract = {We present an internet-based data development, called crowd sourcing, for global urban area mapping. Crowd sourcing is an approach in which non-expert people, called crowds, join a project of producing data with simple procedures. To introducing crowd sourcing for our global urban area mapping, we constructed a crowd sourcing platform with open source GIS software and developed a ground truth data development system the platform. The data development system was for producing ground truth data by digitizing boundaries of urban area with visual interpretation of satellite images. By using the system, we successfully developed over 160,000 records of boundary data in five month. We had an experiment with operation of the system to measure working time by several sizes of work unit: 80 km {\texttimes} 80 km, 20 km {\texttimes} 20 km, and 10 km {\texttimes} 10 km. Medians of working time were 87.2, 6.2, and 1.4 hours, respectively. Our result would be helpful for estimate total working time of crowd sourcing of ground truth data by visual interpretation and would contribute to progress of data-intensive studies of geospatial information, remote sensing, and photogrammetry.},
	keywords = {ASTER, crowd sourcing, urban area mapping, Web-GIS},
	author = {Miyazaki, Hiroyuki and Kimijima, Satomi and Nagai, Masahiko and Iwao, Koki and Shibasaki, Ryosuke}
}
@article {Miyazaki2011,
	title = {Development of a New Ground Truth Database for Global Urban Area Mapping from a Gazetteer},
	journal = {Remote Sensing},
	volume = {3},
	number = {6},
	year = {2011},
	pages = {1177{\textendash}1187},
	address = {Taipei},
	abstract = {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,},
	keywords = {crowd sourcing, global urban, ground truth database, web feature service, web mapping service},
	issn = {2072-4292},
	doi = {10.3390/rs3061177},
	url = {http://www.mdpi.com/2072-4292/3/6/1177/},
	author = {Miyazaki, Hiroyuki and Iwao, Koki and Shibasaki, Ryosuke}
}
