Visualizations by
Greg Shirah
Released on June 7, 2023
Map projections are a way of representing regions on the surface of a spherical object on a flat surface. For example, a continent on the Earth can be represented on a flat map. There are many map projections, but some are more prevalent in our work with scientific visualization data. Map projections are chosen based on the characteristics required by researchers. There is no perfect way to represent a spherical surface on a flat map, so no matter what map projection is chosen distortions occur. Some projections can preserve properties like: area, shape, and direction; so, projections are chosen depending on the scientist's needs.
This visualization shows some of the more common projections that SVS has encountered. Some of these projections have parameters that change the central point of the projection. In those cases, the parameters are animated and shown in the lower left.
Also included in this visualization are circles/ovals that are similar to "Tissot's Indicatrices". These are all circles of the same size on the spherical earth. Map projections distort them depending on the projection. The area of every circle is 1 million km² or about the size of Egypt. With each projection, the distortions of these circles show how shape and area are distorted in different parts of the projection.
The following projections are shown:
equirectangular
robinson
mollweide
hammer
sinusoidal
polar stereographic
lambert azimuthal
albers equal area conic
wrapped to a sphere
mercator
Visualization Credits
Greg Shirah (NASA/GSFC): Lead Visualizer Laurence Schuler (ADNET Systems, Inc.): Technical Support Ian Jones (ADNET Systems, Inc.): Technical Support
Please give credit for this item to: NASA's Scientific Visualization Studio
Short URL to share this page: https://svs.gsfc.nasa.gov/5090