V and H

The Bell Labs V & H coordinate system, developed in 1957 by J. K. Donald, was invented to more easily calculate distances between wire centers (pre-defined nodes) with published VH coordinates using a slide rule. The V H (Vertical and Horizontal) coordinate system is useful for the utility for which it was developed (i.e.distance-based telephone rate computations), but is not nearly as accurate at geodetic coordinates.

The coordinate system is based on the Donald two-point elliptical projection (uses Clarke 1866 ellipsoid). The most valuable feature of the projection is the balance of error (+0.3% scale error east-west along the Mexican and Canadian borders; -0.3% scale error along the approximate center of the United States.)

The unit of measurement in the V & H coordinate system is defined as SQRT .1 mile (~1669.68 ft). These units are to be used only in the V & H coordinate system.

Reference: Peter H. Dana supplied J.K. Donald’s 1957 Bell Labs paper.

The "V and H" projection has no parameters.