I humbly offer the following tale / explanation of how I figured out why my point coordinates in my Civil3D drawing slightly differed from my data collector in case some poor sod has resorted to Google to try to figure out why his coordinates differ by oh so little, yet they shouldn't, and he (or she) doesn't really want to pull their hair out by their roots...

If you survey (i.e. take measurements / shots / GPS observations or point occupations in US Survey Feet, ensure your Civil3D survey database settings and drawing settings are also in US Survey feet. Of course, the flipside to that is if you measure in International Feet, ensure your C3D survey DB and drawing settings are also all set to Int'l feet.


In one of my recent drawings, I observed that the coordinates for a point in the drawing did not match the coordinates for the same point in my data collector. Almost all my surveys are relatively small and I use a 5000,5000,500 local coordinate system to start. The point I was comparing, pt 70, had a Northing value of 6430.735 and an Easting of 5611.5162. Both Northing and Easting differed between data collector and Civil3D 2016 survey database on the order of a little over a hundredth. Not huge, but it bugged me.

I created a new drawing. Then I created a new survey database. Then I imported all the data for this job into the new survey database. I compared points again by visually inspecting point 70: I clicked on the Prospector tab, then on Points. I then scrolled the window at the bottom of the Prospector tab until I found pt 70. The coordinates still differed from the data collector. This was starting to annoy me. I had already verified the value of the coordinates in the ASCII point file from which I imported the data into Civil3D.

Somewhere around this time, a vague light bulb went off: I recalled seeing a setting somewhere recently that showed International Foot – I work in US Survey feet. I checked my drawing settings … nope, US Survey feet set (to check: Toolspace > Settings (tab) > rt click on dawing (@ top) > Edit Drawing Settings…). Then I checked my Survey Database settings: International feet!!! I changed to US Survey feet, then re-imported ALL my data from their ASCII point files… and, voila!, my point coordinates in Civil3D matched my coordinates in my data collector. (To check your survey database settings: Toolspace > Survey (tab) > rt click on the survey database open for edit or open for read-only > Edit survey database settings… ).

This is what drawing settings looked like:

And this is what the survey database settings looked like: