The Geoid

The geoid. The what? The geoid.

Sounds like something to do with the earth - but what is it? Well for starters, you can't see it, you can't touch it, most people have never heard of it, and most will never know anything about it. And yet everyone benefits from it.

The geoid is still an unfamiliar idea to most people even though geodesy , the science that studies the size, shape and gravity field of the Earth, is the oldest of what we call the "geosciences", or sciences which study the Earth.

The geoid is, for all intents and purposes, the same as mean sea level, described in the next section. We study it, by making use of the latest satellite technology, in order to help us measure the Earth we live on. Whether we simply want to know how high we are above sea level when using a handheld GPS receiver or want to build a road faster and cheaper, using the geoid will help.