Augmented map projections
Simulations usually require three dimensions.
Some coordinate systems three dimensional by definition.
Map projections (two surface dimensions) are commonly augmented with a vertical axis to create a three dimensional system.
Various vertical measures are used for these augmentations, such as:
- Mean sea level height, orthometric height, geodetic height, pressure altitude, and others.
These augmentations may be in different units than the other two axes so that the resulting CS may be vertically distorted.
This practice adds additional geometric distortions (now in the third dimension).
Augmented map projection coordinate-space has a (linear) vector space structure, but the CS is a curvilinear CS.