Defining a coordinate system and a geographic transformation for CAD Drawing?

[Behseini]

I am a GIS guy and I occasionally work with CAD Files as well. Now I need to know how I can define a coordinate system and a geographic transformation for a CAD Drawing?
According to ESRI :
You can define a coordinate system and a geographic transformation and create and edit metadata for CAD datasets. The information is stored in external support files and moves with the CAD dataset when it is managed in the Catalog window.
but don't know how to do this ! Can you please let me know or point me to a tutorial to understand this?

[Alfred.NESWADBA]

Hi,

>> Now I need to know how I can define a coordinate system and a geographic transformation for a CAD Drawing?

Do you have AutoCAD Map3D or AutoCAD Civil3D as product? If so you can start command _ADESETCRDSYS to assign a (gis/geographic) coordinate system. With that products it is then also possible to combine different data sources (DWG, SHP, Oracle-Spatial, SQLite-Spatial, ....) into one drawing.

If you don't have one of these products you will have to work (with AutoCAD) in local coordinates and when importing the geometry of the DWG-file into a GIS-dataset you will have to align the manually.

HTH, - alfred -