Images and Units

[Anonymous]

I have a tiff image (1:24,000 USGS Quad) that I want to pull into a drawing. The units of the tiff are metric NAD83. I am using an imperial NCS template because I want my drawing in feet. I set the CAD coordinate system and units to NAD83 metric in toolspace / settings / edit drawing settings. The tiff file has a world file associated with it. I have inserted the tiff file to the drawing via Map menu / image / insert. Everything comes in perfect. I verified this by picking a point on the map and cross referencing the Civil 3D coordinates to Google Earth.

Here is my problem: When I use a simple "dist" command and check the distance along a section line, the distance reads 1609 (1609 * 3.2808 = 5280) rather then 5280 after I have change my units back to feet. I have messed with changing the coordinate system and changing the units after I have brought the tiff by the previously mentioned procedure, but I haven't had any successful results.

I know its probably something simple that I am missing, can someone help?

[Anonymous]

mike

did you try a new dwg  with acad.dwt and set your coord
system to what you want. should be utm83-19F with the 19 changed to the zone you
are in and then inserting your image?

another alternative is to data connect to the image in the dwg
with the correct coord sys.

dave

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<Mike7495> wrote in message
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I
have a tiff image (1:24,000 USGS Quad) that I want to pull into a drawing. The
units of the tiff are metric NAD83. I am using an imperial NCS template
because I want my drawing in feet. I set the CAD coordinate system and units
to NAD83 metric in toolspace / settings / edit drawing settings. The tiff file
has a world file associated with it. I have inserted the tiff file to the
drawing via Map menu / image / insert. Everything comes in perfect. I verified
this by picking a point on the map and cross referencing the Civil 3D
coordinates to Google Earth. Here is my problem: When I use a simple "dist"
command and check the distance along a section line, the distance reads 1609
(1609 * 3.2808 = 5280) rather then 5280 after I have change my units back to
feet. I have messed with changing the coordinate system and changing the units
after I have brought the tiff by the previously mentioned procedure, but I
haven't had any successful results. I know its probably something simple that
I am missing, can someone help?

[Anonymous]

Hi Dave,

Thanks for the reply. I realized my problem: I forgot to scale the image. I set my coordinate system to NAD83 Int'l ft. I inserted my tiff and scaled the metric tiff to feet. By creating a Civil 3D point on a known point on the tiff, and checking the distance down a known section line, I verfied everything worked well.

Mike