3. Coordinate Systems
All CAD files submitted for ATL capital projects must be drawn using the designated coordinate system defined below. This ensures consistency across disciplines and compatibility with airport GIS, BIM, and digital asset systems.
ATL Standard Coordinate System
- Coordinate System Name: Georgia State Plane West Zone (US Feet)
- EPSG Code: 2240
- Datum: NAD83 (2011)
- Units: U.S. Survey Feet
All project base files must be georeferenced and aligned to this coordinate system unless otherwise approved in writing by ATL Engineering.
CAD File Origin Point Requirements
The origin point (0,0,0) for all CAD files must reflect the real-world location corresponding to the project’s base point in the designated State Plane coordinate system.
AutoCAD’s “Base Point” and “Insertion Point” settings must be managed carefully to prevent unintended shifts during file referencing.
Working with External References (Xrefs)
- All Xrefs must retain the same coordinate system alignment and should not be adjusted via user UCS.
- Use of AutoCAD’s
ALIGNorGEOGRAPHICLOCATIONtools to artificially match coordinates is not permitted. - Xrefs must be attached using full path or relative path referencing, not overlay or manual shifting.
Site Calibration & Survey Integration
Consultants integrating field survey or topographic data must ensure that all survey control points are aligned to the ATL geodetic standard. Project setup files may be requested from ATL’s GIS or Capital Improvement team.
Suggest an Edit
If you have a suggested change to this standard, please submit it below:
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