<(longitude, latitude)> coordinates and extends out to the specified radius
around this center point. The resulting circle denotes the "site limits" for
that site. Any Locus is said to be "in the site" when the distance from the
the center of the site to the Locus is less than or equal to the radius of that site
(i.e. falls inside the "circle" of the site centered at <(longitude, latitude)>h
with the specified radius, bound inclusive).
Please note that it is possible for two sites to overlap (e.g. like a Venn diagram), although every mapped site will be centered at a different locus.