National Geodetic Survey Explorer
Maps & Cartography

NAD83 – We’re Not in Kansas Anymore

North American Datum of 1983 (NAD83) is 2-meters from geocentric and uses thousands of monuments with triangulation to create a reference frame for Earth

Maps & Cartography

World Geodetic System (WGS84)

The World Geodetic System 1984 (WGS84) is the spatial reference system of GPS satellites with an error of less than 2 centimeters to the center of Earth.

Arctic Maps Ocean Floor
Maps & Cartography

5 Maps that Explain the Arctic

Mineral extraction, natural gas as well as potential shipping routes. These Arctic Maps display one of the last great frontiers for human development.

Quantile Classification United States
Maps & Cartography

Quantile Classification in GIS

Quantile classification divides classes so that the total number of features in each class are approximately the same (which is useful for showing rankings)