This subsystem provides several facilities of use for navigation and mapping. It provides particular support for the WGS84 model of the Earth, for several commonly used general map projections, and particular support for the United Kingdom map projection.
The support comprises background documentation, interactive user tools, and programmers subroutines.
Of particular note are implementations of the Universal Transverse Mercator and Universal Polar Stereographic projections, and an exact implementation of the Ordnance Survey of Great Britain OSTN02 & OSTN15 projections.
There is the full EGM96 geoid model, the full Ordnance Survey OSGM02 & OSGM15 geoid models, and the Ordnance Survey Digital Terrain Elevation Data (DTED) model of Great Britain with 50 m postings.
Further tools calculate geodesics, and calculate gimbal angles for sight-line pointing devices, both operating with ellipsoidal Earth models.