Ask A Cartographer

Using CAD data with shapefiles

December 03 2007 | 0 comments
Categories: ArcGIS Methods, Map Data

Troubleshooting CAD file onto existing map, I am trying to insert a CAD .dwg file onto a County parcel shapefile and retain the orientation and GCS of the county map. Even after referring to my course material, I have trouble assigning a GCS to the .dwg file, and when I do get it into arcmap, it is very far to the SW of the county's map. I tried to move it on top(false easting, false northing) of the county map, and it moves to the right location, but doesn't line up nicely. I don't know the source of my orientation problems and am afraid to continue on a 'shaky foundation' can you refer me or help? Thank You

Mapping Center Answer:

One of the age-old problems with CAD data is that there is no guarantee that it follows any coordinate system. To help get you a better foundation for approaching this problem, we do have some help topics:

This one as general background:

http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?id=81&pid=77&topicname=Identifying_an_unknown_coordinate_system

This one for dealing with CAD data in particular, which also points to additional resources (note that the table of contents, once you see this topic, has three other topics dealing with this subject):

http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?id=2578&pid=2577&topicname=An_overview_of_spatial_references_and_CAD_data

If after that, and after checking with the CAD data provider you are still having problems, I suggest you contact technical support.

If you would like to post a comment, please login.

Contact Us | Legal | Privacy |