We have a positioning system where we can measure our range without 0.1m from multiple beacons. The placement of the beacons is about on a 1-2km box. So we could get anywhere from 2-4 ranges from the beacons. The beacons are surveyed in place to an accuracy of about 1m.
We found the PHP code for the range case: Trilateration using 3 latitude and longitude points, and 3 distances and we're testing this in our "C" program w/ double precision math.
Questions: We're looking to get the most accurate position projection in LAT,LONG over a short area say max range up to 2km. What's the best aproach to get the least errors in the solution math? How big will the position errors be in meters?
Is there a code example of finding the two solutions in lat,long is we only have 2 ranges?