# Converting the local coordinates to GPS (lat, long)

I am having the XYZ points in some local coordinate frame. Each point I have, can also be represented as the distance from the origin and the azimuth angle it makes with one of the horizontal axis.

I also have the GPS coordinates(lat,long) and the heading corresponding to the (0,0,0) point of the local coordinate frame.

I need to convert all the points in the lat,long.

The approach I can think of is to use the Destination point given distance and bearing from start point formula from this link, as I have the:

• starting point(long,lat corresponding to the origin)
• distance between the origin and the actual point being converted to long,lat

But I am not sure what will be the bearing required in the formula. Does it relate to the azimuth, I have for each point?

• What software are you using? Some software will allow you to create a CRS with your local origin. Are the points in metres from the origin? Can you give an example of some of the points you have? Commented Jun 18, 2019 at 1:14
• Currently, I am looking to achieve this without any software. Yes the points are in metres from the origin. Apparently its the lidar data, below is the example of one such point 0.12 4.8 -7.6 50 (x y z intensity) Commented Jun 18, 2019 at 1:32
• You can project to geographic coordinates with OGR if you're keen on writing your own package. You will need to define your own CRS with a vertical datum (ellipsoidal perhaps) and offset the standard false easting and northing with your known starting point. Commented Jun 18, 2019 at 1:36
• Thanks for the info. Can you please elaborate more on this technique, as I am new to these type of conversions and standards. Commented Jun 18, 2019 at 1:46
• It might be simpler to add the values to your known coordinate, but it will need to be UTM (Universal Transverse Mercator), what is your origin for the example point? Are the relative coordinates positive up, positive east, positive north? what programming language are you using? I know python, VB6, VBA, VB.net, C# and C++ (and others that aren't used any more) it would be more useful to frame an answer in a programming language that you understand. Commented Jun 18, 2019 at 1:56