2011

See also:
■ Defining Coordinate Systems (page 89)
■ Grid Data Files and Datum Shifts (page 102)
To assign coordinate systems
■
To use coordinate systems with maps (page 145)
■
To assign a coordinate system to a source drawing (page 146)
■
To assign a coordinate system to the current drawing (page 147)
■
To determine if a coordinate system is geodetic (page 149)
■
To turn off a global coordinate system (page 150)
■
To see the assigned coordinate system for a source drawing (page 151)
■
To transform the coordinate system of a drawing (page 152)
Overview of Coordinate Systems
With AutoCAD Map 3D, you can combine data from maps using different
coordinate systems. To do this, you specify the coordinate system used for
attached drawings and for the current drawing. When you bring objects from
attached drawings into the current drawing, the objects are transformed to
the coordinate system of the current drawing.
The coordinate system you assign to your drawing specifies the system that
was used when creating the drawing. For example, if you created a map using
Universal Transverse Mercator, Zone 27, US Survey Feet, you assign the code
UTM-27F to the map.
You specify the coordinate system used for the current drawing and for
attached source drawings before querying any items from the source drawings.
When you query objects from source drawings, AutoCAD Map 3D
automatically converts them to the coordinate system of the current drawing.
This operation is called coordinate transformation. When you save objects back
to source drawings, AutoCAD Map 3D reverses the conversion.
The coordinate system code and definition are stored in the drawing file. You
can share the drawing with anyone using Autodesk Map 2000 Release 4 or
later, and they will have the correct coordinate system.
When the coordinate system you select is assigned to the selected attached
drawings, a backup file, with a .bak extension, is made of each source drawing
before assigning the coordinate system information.
Assigning Coordinate Systems | 143