Matching my shapefile to a DGN that has an unknown projected coordinate system?

Question

I was asked to pull the 2-foot contours from Aiken County in South Carolina (http://www.dnr.sc.gov/GIS/lidarstatus.html) and send them to a person working in Microstation to match the scale and location of their working DGN file.

I successfully downloaded the file gdb, clipped it appropriately to the size of the project site, and converted it to DGN to send to my coworker.

The source properties are as follows:

Projected Coordinate System: 
NAD_1983_NSRS2007_StatePlane_South_Carolina_FIPS_3900_Ft_Intl
Projection: Lambert_Conformal_Conic
Geographic Coordinate System:   GCS_NAD_1983_NSRS2007

When she references the contour DGN into her working file, it is located thousands of miles away and is not scaled correctly. Turns out the geographic coordinate system of her file is "unknown." What can I do?

Answer 1

The only way I can think of is to try to guess what the unknown SCR is. If they could give you coordinate of know point of the project and knowing where the project is located you could then try to find the DGN CRS (you'll find a lot of question like these one if you don't know where to start).

Just be careful of the unit (I dont know if that's the case with DNG but in DWG you often get millimeter instead of meter as unit).

If you dont get result this way it may happen that the DGN is not using any reference system at all and is just randomly placed anywhere, in this case you will have to georeference the DGN to match your contour file...