Transformation of Survey Coordinates—Another Look at an Old Problem

Abstract

A procedure is discussed that combines the best aspects of the usual “rigid body” (three parameter affine) and the similarity (Helmert) least-squares procedures found in most civil engineering enhancements to popular computer-aided design programs. The procedure will work to transform North American Datum of 1927 coordinates into the North American Datum of 1983 (NAD83) system, and will work in transforming arbitrary coordinates (coordinates derived in an arbitrary system) to NAD83. In all of these transformations, coordinates of a number of points are required in both systems, and provide the basis for the transformation.