Convert the latitudes and longitudes to radians, observing that latitude is
positive in the northern hemisphere, and negative in the southern
hemisphere, and by convention among astronomers east longitude is positive
and west longitude is negative (why? No one knows).
Let's call one point the 'start point' and the other one the 'end point.
Let L be the start point latitude in radians, and D be the end point
latitude in radians.
Let LHA be the difference between the two longitudes, in radians.
Then the sine of the distance angle between the two points, measured from
the center of the earth, is:
sin(distance angle) = sin(L) * sin(D) + cos(L) * cos(D) * cos(LHA)
and the angle in radians of the distance angle is:
da = asin(distance angle).
Convert this angle to degrees.
On a theoretically spherical earth, an angle of one degree subtends 60
nautical miles. So multiply the distance angle in degrees by sixty, and you
have what's called the "Great Circle Distance" between the points in
nautical miles of 6000 feet. To convert to land miles, multiply by
6000/5280.
Regards,
Tom Dacon
Dacon Software Consulting
"DellaCroce" <De********@toast.net> wrote in message
news:O3**************@TK2MSFTNGP11.phx.gbl...
Does anyone here have the formula for calculating distance give two pairs
of Longitude/Latitude coordinates? Please share this with me if you would.
--
Greg