Georeferencing (giving coord.) to a drawing

[khartman27]

Hello:

I have a Acad Map 2000 drawing file which was originally created without geographic coordinates (Lat/long, utm etc). The map was digitized from a scanned airphoto. I need some way of georeferencing (giving UTM coordinates) to this drawing. I have control points of known location (UTM), but how can I make autocadmap use these to assign UTM coordinates to the drawing. Someone else suggsted "Rubbersheet" - but that appears to work only for two drawings be "matched up". Any ideas on how i can do this?

Thanks

[JeremiahM]

First you will need to set up a new drawing with a Coordinate System using "Map>> Tools>> Assign Coordinate System".

Then you can use "Map>> Tools>> Track Coordinate Systems" to input the known UTM points.

Finally insert your digitized drawing into this drawing and use "Map>> Tools>> Transform" to match the digitized points to the known points (this tool only changes scale and rotation unlike rubbersheet which morphs data).

You can refer to help on using these tools.

Jeremiah

[khartman27]

Thanks for your help - I'm using AutoCad Map 2000 and there only seems to be an option - Map - Tools - Track coordinates - which the help file says allows the display of coordinates in different coordinate systems as you move the cursor through the drawing window. If I use this on a new drawing for which I've assigned UTM Nad 27, it says "unknown command" when I try to input my known UTM points. Are we on the same page here?

THankls

[mohobrien]

What I use is ALIGN. I open a new drawing. If I have the coordinates of two points reasonably far apart on the drawing, I draw a pline using those two coordinates. Zoom to the extents. Assign the coordinate system. Insert the unknown drawing and move and scale the insert so that you can see both on the screen. Then using a transparent zoom, I align the insert known coordinates with the pline end points. When it prompts for "Do you want to scale", say yes and it's pretty close.

[JeremiahM]

Yes, that is the tool.

First make sure the Track Coordinates box is showing the correct System, if not click the blue globe icon and set it.

Start the POINT command.

Next type in the coordinates (if you need Lat Long right click in the box and you can turn it on)

Then press DIGITIZE button (red pencil) to have it placed on in the drawing.

[shahafridi708112]

Hi Jeremiah, It seems you can help me. I use AutoCAD 2015 and have a CAD drawing file which is in mm and scale is 1:2000. The drawing is also rotated 6.5 degrees from True north. ArcMap only uses two control points for CAD drawings for georeferncing (to be used in GIS) but there is only one UTM coordinate in the South Western corner of the drawing but I need another control point for georeferencing in North Eastern corner (i.e. diagonally). the different images of the drawing are attached herewith for your reference. An expert who was earlier working on it left a clue that the other corner would be calculated using Trigonometry. I makes sense to me but how to proceed.
Thanks in advance

[Novarese]

Man, you are referring to a 2005 post, i.e. 10 years ago...

[JeremiahM]

Funny thing is, most of us still seem to be here!

[JeremiahM]

shahafridi708112 I do not see the attached files, can you please try to attach them again.

Jeremiah

[Jmurphy]

shahafridi708112 I do not see the attached files, can you please try to attach them again.

Jeremiah

Check back in 2025.