Module: latlon-ellipsoidal

A latitude/longitude point defines a geographic location on or above/below the earth’s surface, measured in degrees from the equator & the International Reference Meridian and in metres above the ellipsoid, and based on a given datum. As so much modern geodesy is based on WGS-84 (as used by GPS), this module includes WGS-84 ellipsoid parameters, and it has methods for converting geodetic (latitude/longitude) points to/from geocentric cartesian points; the latlon-ellipsoidal-datum and latlon-ellipsoidal-referenceframe modules provide transformation parameters for converting between historical datums and between modern reference frames. This module is used for both trigonometric geodesy (eg latlon-ellipsoidal-vincenty) and n-vector geodesy (eg latlon-nvector-ellipsoidal), and also for UTM/MGRS mapping.