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Geographic Projection In AutoCAD

Hello all, I am new to AutoCAD but have backround in GIS-MapInfo. I have a bunch of AutoCAD drawings (a local fiber network) that I need to convert to GIS format, and that part I know how to do. My problem is that I am trying to determine a co-ordinate system the CAD files were done in. I dont know how to accomplish this. I have AC-2008, and I tried looking in, "View-Render-Light-Geographic Location" I cant seem to find any other place where I can view the existing, if any, settings.

Thanks in advance for answering My questions

thanks much

Steven

Reply to
maestro1115
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Acad dresses up generic Cartesian coordinates to look like other units. The drawing's author sets this up when they start a drawing, but it can also subsequently be changed by anyone, creating all sorts of havoc, since a unit is a unit. A 'unit' van be an inch, a foot, millimeter, meter, mile, etc., so if you change them without scaling the model up or down, you've just changed the real-world size of everything in it.

Unless someone keyed their coordinate system to some other 'real world' location and orientation, I'm afraid you will have to devise a way to do so.

Reply to
Michael Bulatovich

"Michael Bulatovich" wrote in news: snipped-for-privacy@news1.newsguy.com:

How 'local' are the networks? Buildings, city blocks or larger regions? Maybe start by looking for an object in the drawings which has a known dimension in the real world and do a 'dist' on it? Might be difficult with fibre optics ... One of my sons did fibre-optic drafting work using ACAD for Telstra in Oz - I'll ask if there are any conventions.

Reply to
Troppo

Wouldn't be surprised if they weren't to linear scale.

Reply to
Michael Bulatovich

Save As dxf and drag the dxf file into a text editor to read what units are being used. You can corelate what you read with what is in the dwg file and take it from there.

Reply to
clintonG

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