Editing .dwg file from GIS Tutorial 1 book

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07-22-2013 07:40 PM
by Anonymous User
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Original User: MCline19

I am using the ESRI GIS Tutorial 1 book for ArcGIS 10. 
I am trying to complete assignment 6-2 on page 228 and 229. 

I'm not a novice to ESRI or GIS and yet for some reason I cannot figure this out.  Any help would be greatly appreciated!

When I add the aerial imagery (25_45.tif and 26_45.tif) and the CampusMap.dwg to the mxd the CampusMap is no where near the aerial imagery and it is far too large to lay over the aerial imagery. 

I have tried defining the projection of the .dwg file.   I have tried exporting it to a .gdb and defining the projection.  I have tried exporting each part of the file to multiple shapefiles and defining the projection. 

Surely I am missing something simple here.  A simple step I am overlooking? 

Please help my clouded mind!  THANKS!!!
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3 Replies
by Anonymous User
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Original User: jimcousins

I can not help you directly, as I do not have a copy of this book. However, it sounds as if you have a mismatch in coordinate systems. Try adding the CAD file on it's own to a new, blank map and see what coordinate system pops up. If it is undefined, you will need to determine the coordinate system of the CAD file, and define it before it will align with data in a different system.
Regards,
Jim
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by Anonymous User
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Original User: MCline19

That does seem to be the problem.  The .dwg file does not have a defined coordinate system.  I am not sure how to figure out what its defined coordinate system should be in order to project it to the one I am using.

Any thoughts?
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JimCousins
MVP Regular Contributor
Yes. Add the streetmap data to a map (or any basemap data you have accesss to).
Zoom to the location this data should reside.
add the CAD Data. It will be in the wrong place.
Begin guessing the coordinate system ie: start changing the data frame coordinate system.
Go through UTM and State Plane, NAD83 and NAD27(less likely these days), and feet and meters.
If your CAD data shows up where it should be, then that is the coord sys of your CAD file.
Good luck,
Jim
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