HydrometronicsHeritage Content

Earth-Centered Earth-Fixed (ECEF)

also known as Geocentric Cartesian CRS

World XYZ
The Z axis extends from the geocenter north along the spin axis to the North Pole. The X axis extends from the geocenter to the intersection of the Equator and the Greenwich Meridian. The Y axis extends from the geocenter to the intersection of the Equator and the 90E meridian.

Topocentric Coordinates

Topocentric Coordinates

Graphic and text from Guidance Note 7-2 @ www.epsg.org

A topocentric coordinate system is a 3-D Cartesian system having mutually perpendicular axes U, V, W with an origin on or near the surface of the Earth. The U axis is locally east, the V axis is locally north and the W axis is up forming a right-handed coordinate system. Topocentric coordinates shift the geocenter of ECEF to a local point of interest. Why?

Scalable Visualization without Distortion

Indonesia Topographic
Indonesia in topocentric coordinates as presented by Matlab. One can rotate this image in Matlab or in any 3D geophysical visualization environment to any perpendicular perspective, which will be free of 2D mapping distortion.

The real world is 3D. Our new visualization environments (VE) are 3D. Why incur the distortions of a 2D map projection entering real-world data into a VE? ECEF and topocentric coordinates a paradigm shift in the way we view our data, perhaps a valuable perspective that will extract new information. The time is ripe to explore ECEF.

Download the entire presentation "Earth Centered Earth Fixed: A Geodetic Approach to Scalable Visualization without Distortion" available in three formats.
Download "Earth Centered Earth Fixed - Full Screen".
Download "Earth Centered Earth Fixed - Speaker's Notes".