Latitude Longitude Triangulation?

Question

I'm looking for a mathematical way to determine latitude and longitude if I have three known gps coordinates and the associated distances between them and the unknown location?

Answer 1

Use least squares.

Answer 2

For larger distances, spherical geometry.  

For relatively small ones, treat the earth as flat, and the coordinates as xy coordinates.   For the distances to work with the degrees of the coordinates, you will have to use the cosine function to convert from one to the other.  (While degrees of latitude are about 69 miles all over the earth, degrees of longitude vary from the same at the equator to 0 at the poles.)

   You have the center points of three circles and the radius of those circles.  They are supposed to intersect at one point, so you can treat them in pairs to find the intersection points of each and throw out the ones that done match

http://mathworld.wolfram.com/Circle-Circ...