AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Valued Contributor
asloat
Posts: 87
Registered: ‎06-07-2011
Message 1 of 4 (120 Views)

Survey data editing, yet again

120 Views, 3 Replies
08-05-2013 07:25 AM

I see this asked al ot but am not exactly seeign what I am looking for. My understanding is Civil3D tries to prevent editing of survey data but ends up locking out legitimate edits int he procress.

 

e.g.

 

I just processed 4 fbk files into a Civil3D DB and utilized GPS derived initial points to set them in NAD83 for the most part. Everything looks good, but as people know, GPS derived elevations are not so hot. As such we also ran a proper level run across all our 10 control points and have adjustments to make to the control point elevations.

 

I see three ways to accompolish this and want some feedback on the ideas merits and flaws.

 

1. I can edit the FBK files so the measured heights result in replicatign the desired Z values after processing. I personally don't like this idea as it is rather ham fisted and essentially requires you to input bad data in a good file just to get the good resutls.

 

2. I can unlock the points edit their Z value and that is that. This of course breaks soem of the survey DB functionality for those points which I don't like.

 

3. I can use the survey command window to "MOD ELEV" the points. I am thinking this is pretty mucht he same as #2 and has the same draw backs.

 

Any advice on this or comments please? This really illustrates Autodesks disconnect with how survey work is really done unfortunatly. They should have a right click "Enter data corrections" option that keeps the DB integrity in check but allows such edits.

Distinguished Mentor
rl_jackson
Posts: 805
Registered: ‎01-20-2008
Message 2 of 4 (113 Views)

Re: Survey data editing, yet again

08-05-2013 07:47 AM in reply to: asloat
I would modify the original control points and then re-import the FBK files so they adjust the data themsleves
C3D12-13
Win7x64 6gb
Valued Contributor
asloat
Posts: 87
Registered: ‎06-07-2011
Message 3 of 4 (112 Views)

Re: Survey data editing, yet again

08-05-2013 07:50 AM in reply to: rl_jackson

rl_jackson wrote:
I would modify the original control points and then re-import the FBK files so they adjust the data themsleves

Only way to do that is to either figure out how to change the measured vertical angle or edit the measured setup heights. Not ideal from an integrity standpoint, but perhaps that is best option in Civil3D

Distinguished Mentor
rl_jackson
Posts: 805
Registered: ‎01-20-2008
Message 4 of 4 (103 Views)

Re: Survey data editing, yet again

08-05-2013 08:23 AM in reply to: asloat
If you modify the control point the elevations will adjust on re-import based on the new elevation at each control point. Now your back sight elevation may not check with respects to the adjustment you made from your level loop, but who cares, elevations comes from the instrument height/position.
C3D12-13
Win7x64 6gb
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