Converting Lat-Long Coordinates to Absolute Distance - Flat Earth

Andy,

Try this great circle calculator.

Mario

Andy Eng wrote:

Hi Andy: If the latitude is low you can use the Pythagorean Theorem: distance= sqrt( (lat1-lat2)^2 + (lon1-lon2)^2 ) to get the separation in degrees. At the equator a degree is a nautical mile, so you're done. A nautical mile is about 6076 feet.

But remember that while a degree of longitude is a nautical mile at the equator, it is zero miles at the pole. You'll only be off by about 40% with the longitude portion at 38 degrees latitude.

If you just want to do this > Hello All,

CHAD solution: enter both sets of coordinates into a hand held GPS, and let the GPS figure out the distance between the points!

Here's some code, if you do that:

'/* compute inner product on unit sphere */ slInner = Sin(slLat1) * Sin(slLat2) + Cos(slLat1) * Cos(slLat2) * Cos(slLon1 - slLon2)

'/* compute arc cosine of that inner product, avoiding possible ' computational inaccuracies that would induce overflow */ If slInner >= 1 Then slArc = 0 ElseIf slInner

Here's something I was reading this weekend that might help:

Also, there's Google Earth. Get the free version, and you can use ctrl-6 to measure. Not quite as easy as just entering two coordinates, but almost.

Roy nar12605

Why would we add that error checking?

sin * sin + cos* cos cannot exceed 1, or -1 and cos(L1-L2) also cannot exceed 1 or -1

methinks, for now.

Just searching for may pocket calc... :-)

w.

Not all computers/languages play nice that way...