2011

Table Of Contents
Data\Autodesk\Geospatial Coordinate Systems\Canada, and give it the
name Ntv2_0.gsb.
3 Using a text editor such as Notepad, open Nad27ToNad83.gdc (located
by default in the C:\Documents and Settings\All Users\Application
Data\Autodesk\Geospatial Coordinate Systems folder).
4 Delete the initial pound sign (#) from the line that begins:
#.\Canada\Ntv2_0.gsb.
To use version 1 of the Canadian National Transformation
1 Obtain a copy of the data file.
2 Copy it into the C:\Documents and Settings\All Users\Application
Data\Autodesk\Geospatial Coordinate Systems\Canada folder, and give it
the name grid11.dac.
3 Open Nad27ToNad83.gdc.
4 Delete the initial pound sign (#) from the line that begins:
#.\Canada\grid11.dac.
For more information on editing GDC files, see
Grid Data Catalog (GDC) Files
(page 104).
Coordinate System Files
AutoCAD Map 3D uses certain files for storing coordinate system definitions
and defining datum (page 2059) transformation information.
Following is a list of these files. Files that should not be modified are marked
with an asterisk (*).
DescriptionFile
Grid Data Catalog file for transformations
within Australia. Default grid data files:
Agd66ToGda94.gdc
Vic_0799.gsb, nt_0599.gsb, and
TAS_1098.gsb. Default fallback
datum
(page 2059): ASTRLA66.
Grid Data Catalog file for transformations
within Australia. Default grid data file:
Agd84ToGda94.gdc
Creating New Coordinate Systems | 113