Reference point

Current consensus

A reference point is a complete set of values for latitude - longitude - and height above the reference ellipsoid which is used as an initial starting point for subsequent orthogonal offset X, Y, Z values from that point. All roadway geometry, maps of intersections, lane and curve descriptions, and other geometrical data that are encoded in this standard use a system of local reference points to index and offset the data that follows. Also called an anchor point.

Explanation