Central Meridian
Maps & Cartography

Where is the Central Meridian?

The central meridian is the center line of longitude for projection systems. Projected coordinate systems often use it as a reference point for a x-origin.

Datum Transformations: NAD27 Shift to NAD83
Maps & Cartography

Geodetic Datums: NAD 27, NAD 83 and WGS84

Ellipsoids, survey benchmarks and triangulation – these are the ingredients for geodetic datums. NAD27, NAD83 and WGS84 are common datums in North America.