CAD Coordinate system

[my.yari90]

Hello,

I'm facing a bit of a conundrum and could really use your expertise to help me out.

Here's the deal: I've located a building with control points and Northing, Easting coordinates for an Aviation group to analyze the helipad location. So, I sent over the coordinates, but the building didn't show up in the right spot on their system. The problem is, I have no clue about the coordinate system the Aviation group is using. To fix this, I need to figure out what coordinate system my CAD/Survey data is based on. Any suggestions on how to accurately identify the coordinate system used in CAD/Survey data? Any tools or methods you can recommend?

[tcorey]

Are you a Civil 3D user?

Go to Settings tab of Toolspace, right click the drawing name and Edit Drawing Settings. Go to the Units and Zone tab. If a coordinate system has been assigned, it will be shown here. If none has been assigned, now you've got some sleuthing to do. Get a known latitude/longitude. Use _GeographicLocation command. This will place you on the world and will suggest coordinate systems you can assign to the drawing.

[Pointdump]

Hi Mahsa yi,
More details please on how you got the control points. And can you post the Aviation Group's drawing?
Dave