GIS::Distance::Constants - Constants used by formula classes.
Number of kilometers around the equator of the earth.
Number of units in a single decimal degree (lat or lon) at the equator.
This value is derived from:
$gis = GIS::Distance->new( 'Haversine' ); $DEG_RATIO = $gis->distance( 10,0 => 11,0 )->km() / $KILOMETER_RHO;