• Industries
  • Products
  • Buy
  • Services & Support
  • Communities
  • Discussion Groups

    AutoCAD Map 3D

    Reply
    Active Member
    Posts: 7
    Registered: ‎06-25-2009

    Setting Up Coordinate System / Geo-Referencing Help!!

    265 Views, 4 Replies
    08-14-2012 06:27 AM

    I have an Map that was drawn in regular autoCAD drawn 1:1.  I know the coordinate system that I need to assign to it and some known coordiante but how to I go about getting my current map to be correctly geo-refenced.  I am relatively new to AutoCAD map.  Is there a way to tell AutoCAD map that a certain few points are at certain coordinates, and the rest falls into place?  Thanks in advance for any help.

     

    Please use plain text.
    *Expert Elite*
    antoniovinci
    Posts: 1,136
    Registered: ‎06-03-2011

    Re: Setting Up Coordinate System / Geo-Referencing Help!!

    08-14-2012 10:55 AM in reply to: bbrou25

    No way: the assigned CRS (command _ADESETCRDSYS) will affect the whole map.

    If you have survey points in a local coordinate reference system, you could _ALIGN them snapping to known nodes belonging to the main CRS.

    Other ideas, gentlemen..?

    Please use plain text.
    Valued Contributor
    ro_fr
    Posts: 84
    Registered: ‎12-08-2011

    Re: Setting Up Coordinate System / Geo-Referencing Help!!

    08-14-2012 10:46 PM in reply to: bbrou25

    Hi,

     

    I'm not sure if I do understand what you want to do but there is a Map command called _adersheet which migth be helpful in your case. Just check the Map manual for further details,

     

    Rob

    Please use plain text.
    Distinguished Contributor
    Posts: 208
    Registered: ‎02-14-2008

    Re: Setting Up Coordinate System / Geo-Referencing Help!!

    08-15-2012 05:48 AM in reply to: ro_fr

    What I've done in the past is insert overhead images that are georeferenced, then move my CAD file over the image but that's still eyeballing it, not exactly georeferenced.

    Another way is if you have shape files that correspond to your CAD file in a way that you can match them up.

    Please use plain text.
    Active Member
    Posts: 7
    Registered: ‎06-25-2009

    Re: Setting Up Coordinate System / Geo-Referencing Help!!

    08-15-2012 06:15 AM in reply to: snakerancher

    I actually was able to obtain an shape file that corresponds to my CAD file.  My thought were they same, connect to the shape file, move my CAD drawing "on-top" of the shape file, and then my CAD file would be geo-referenced.

     

    This is the problem, I am having issues with drawing units.  The original CAD file was drawing in architectural units (smallest units being an inch). The shape file looks like it wasn't necessarily drawn in units, or I guess since it is using the coordinate system LA83-SF-MOD, its units would be US Survey Foot.  

     

    There in lies my problem, when I connect and bring in the shape file it is 1/12 the size of my corresponding CAD drawing.  The Shape files 1 unit = 1 foot, whereas the CAD drawings 1 unit = 1inch.

     

    I can scale down the CAD drawing by 1/12 and it will match up but I this CAD map is also an XREF to 10 other maps, I would have to open then and scale them down, line them up, etc. 

     

    Any ideas to avoid this. Thanks.

    Please use plain text.