c# - Adding distance to a GPS coordinate

Question

I'm trying to generate some points at random distances away from a fixed point using GPS.

How can I add distance in meters to a GPS coordinate? I've looked at UTM to GPS conversion but is there a simpler method to achieve this?

I'm working on Android platform just in case.

Cheers, fgs

Answer 1

• P0(lat0,lon0) : initial position (unit : degrees)
• dx,dy : random offsets from your initial position in meters

You can use an approximation to compute the position of the randomized position:

 lat = lat0 + (180/pi)*(dy/6378137)
 lon = lon0 + (180/pi)*(dx/6378137)/cos(lat0)

This is quite precise as long as the random distance offset is below 10-100 km

Edit: of course in Java Math.cos() expects radians so do use Math.cos(Math.PI/180.0*lat0) if lat0 is in degrees as assumed above.