The National Map Corps (TNMCorps) is a crowdsourced mapping project that relies on volunteers to assist the USGS National Geospatial Program by collecting and editing man-made structures data for The National Map. Through their participation, volunteers make significant contributions to the USGS’s ability to provide the Nation with accurate mapping information.
Volunteers collect and update 10 different structure feature types in all 50 states, as well as in Puerto Rico and the U.S. Virgin Islands. The structure feature types include; schools, colleges and universities, fire and EMS stations, law enforcement, prisons and correctional facilities, hospitals, ambulance services, cemeteries, and post offices. Volunteers improve the structures data by adding new features, removing obsolete points, and correcting existing data. Fellow volunteers peer review the edits, which are then incorporated into The National Map and ultimately into U.S. Topo maps. As of May 2017, over 2,200 users have made more than 359,000 edits to 264,000 unique points.
Getting started is easy. After walking through a simple registration process, volunteers begin editing using an internally developed web-based mapping platform that was released in August 2016. The primary base layer uses The National Map Web services and consists primarily of 1-m resolution digital orthophoto imagery provided by the U.S. Department of Agriculture National Aerial Imagery Program (NAIP), which is supplemented by 2-ft or better high-resolution orthoimagery over urban areas.
TNMCorps incorporates a variety of strategies to motivate and engage volunteers while simultaneously facilitating focused data collection resulting in high-quality data. These strategies include a tiered editing process, mapping challenges, virtual recognition badges, social media engagement, monthly newsletters, and regular news releases. Volunteers from the general public include youth from various organizations such as the 4-H and scouting, retirees, students, and anyone with an interest in contributing to The National Map.
USGS TMNCorps volunteer contributions from March 29, 2012, to June 27, 2017, with FY2017 edits highlighted. Each point on the map (in orange) represents a single volunteer-edited structure feature. These volunteer contributions include edited, added, verified, and deleted points.