shrug-l: .DGN file not lining up
tcorbin at egisassociates.com
Wed Jun 6 07:41:06 EDT 2012
First thing I would do is delete any PRJ or World file associated with the
DGN and then just add it as a layer to a new blank map. Then see where it
does come in. Check the coordinates. If they are around 5,000 5,000 or
10,000 10,000, then the DGN is in an assumed or local coordinate system and
not a real world system. This still means you will need to figure out a way
to georeference it but at least you know.
If it is has coordinates that are something else, then it becomes an
exercise in trial and error. You just have to keep trying different
coordinate systems and datums until you find one that works. Keep in mind
you will most likely never find one that give a perfect fit but you should
be able to come close. My experience has shown me to start with a different
datum than the one they say it is in. If they say it is in NAD 83 try NAD 27
or NAD 83 HARN or NAD 83 CORS 96 and so on. Also watch the scale of the DGN
compared to data in a known and verified coordinate system. If the scale is
off this means the units are different.
Lastly, you could go to the field and locate a couple of points found in the
DGN with GPS and use those as control to georeference.
Wish I had a better answer but you have stumbled onto one of the common
problems. I run into this all the time when working with data from others.
Tripp Corbin, MCP, CFM, GISP | Chief Executive Officer
<http://www.egisassociates.com/> eGIS Associates, Inc.
tcorbin at egisassociates.com | www.egisassociates.com
678-710-9710 ext 21 | 866-304-3864 Fax
Esri Certified Trainer | Esri Certified Desktop Associate
From: shrug-l-bounces at lists.dep.state.fl.us
[mailto:shrug-l-bounces at lists.dep.state.fl.us] On Behalf Of Brandt, Holli
Sent: Tuesday, June 05, 2012 5:21 PM
To: shrug-l at lists.dep.state.fl.us
Subject: shrug-l: .DGN file not lining up
Hello SHRUGgers -
I received a microstation file(.dgn) from a consultant that was supposed to
be in State Plane East but when I add it into an existing ArcMap project
(where all data is in State Plane) it ends up nowhere near our layers.
I tried these two methods several times with no success :
"Transform CAD data in ArcMap to line up with other data"
"Define the projection for CAD data for use in ArcMap"
Even tried georefencing the .dgn file but unfortunately do not have enough
above ground feature to match it up exactly.
I contacted the consultant but they are no longer working on the project and
there isn't any additional funds to pay them, so I am out of luck there.
Can anyone out there offer any suggestions?
Thanks - Holli
Holli M. Brandt
Senior Civil Engineer Specialist
Separated Systems Management Branch
Utility System Management Division
Seattle Public Utilities
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