map projection


GIS Data

This overlay showing WGS 84 Ellipsoid Mercator in Blue and the Spherical Web Mercator in Red WGS 84 highlights the spatial inaccuracies of the latter projection.This overlay showing WGS 84 Ellipsoid Mercator in Blue and the Spherical Web Mercator in Red WGS 84 highlights the spatial inaccuracies of the latter projection.

National Geospatial-Intelligence Agency’s Web Mercator Advisory Notice

The National Geospatial-Intelligence Agency (NGA) has an advisory notice posted on its site warning about errors users of the popular Web Mercator projection stating, “the use of Web Mercator and other non-WGS 84 spatial reference systems may cause geo-location / geo-coordinate errors up to 40,000 meters.”  The NGA further advised, […]

Maps and Cartography

Unfolded Dymaxion Map (dashed lines indicate fold points) by Eric Gaba, 2009.

Dymaxion Map Projection

Humans have always had a particular fascination with understanding the world around them, and this appeal can be seen in the large number of maps invented throughout history starting with the ancient Greeks. All different varieties of maps have appeared, highlighting certain geographical, cultural, political, or social phenomena. Maps are […]