Coordinate System Jargon: geoid, datum, projection
The road to choosing custom projections is not paved with sundrops and lilies. It is time to start learning the nuts and bolts of coordinate systems.
Minute Markers:
0:27 Geodesy, the geoid.
1:10 Ellipsoid, geographic coordinate system.
2:09 Can't effectively measure with ellipsoid.
3:21 Planar coordinate system.
3:49 Geodetic datums.
5:41 Projections.
6:47 REMEMBER this, degrees vs. linear units.
7:10 Three types of projections.
7:32 Recap.
All images included are in the public domain, though the geoid image was originally created here I believe (correct me if I'm wrong):
http://www.esa.int/spaceinimages/Imag...