GIS::Distance::ALT - Andoyer-Lambert-Thomas distance calculations.
The ALT formula is intended as a much faster, but slightly less accurate, alternative of the GIS::Distance::Vincenty formula. This formulas is about 5x faster than Vincenty.
The code for this formula was taken from Geo::Distance::XS and modified to fit.
A faster (XS) version of this formula is available as GIS::Distance::Fast::ALT.
Normally this module is not used directly. Instead GIS::Distance is used which in turn interfaces with the various formula classes.