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Least Squares in Civil 3D

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BulldogDrafting
(@bulldogdrafting)
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Has anyone figured out how to do Least even squared adjustment in civil 3d without having to use survey network? I am able to do it in Carlson and they make it easy to do so but switching between programs when its not necessary would be nice. 

 
Posted : August 20, 2022 8:20 am
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bobwesterman
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Posted by: @bulldogdrafting

Has anyone figured out how to do Least even squared adjustment in civil 3d without having to use survey network? I am able to do it in Carlson and they make it easy to do so but switching between programs when its not necessary would be nice. 


I'd have to say it can't be done.  If you don't have a network you don't have observations.  Nothing to adjust.

 
Posted : August 20, 2022 8:31 am
Squirltech, not my real name, Rover83 and 1 people reacted
BulldogDrafting
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@bobwesterman Thanks. I suppose I will just do what I need in Carlson, Save the DWG and then Reopen in CIVIL3d

 
Posted : August 20, 2022 8:35 am

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Rover83
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Use the survey program to analyze and adjust survey observations.

Use the drafting program to draft.

They're both good programs but are targeting different functions. Use them for their intended function.

My two cents...

 
Posted : August 20, 2022 9:55 am
Jaccen, Squirltech, BulldogDrafting and 2 people reacted
Mark Mayer
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I've worked with Civil 3d and its precursors, Land Desktop and Softdesk, since 1997. In that time I've worked in several offices with dozens of users, many more experienced than me. I have yet to meet a single person who has successfully performed a traverse adjustment of any kind using the tools Autodesk provides.  

 

 
Posted : August 20, 2022 6:26 pm
Steven Metelski, Jaccen, Moe Shetty and 1 people reacted
bobwesterman
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Posted by: @mark-mayer

I've worked with Civil 3d and its precursors, Land Desktop and Softdesk, since 1997. In that time I've worked in several offices with dozens of users, many more experienced than me. In all that time I have yet to meet a single person who has successfully performed a traverse adjustment of any kind using the tools Autodesk provides.  

 

I used to do it all the time, starting withe one of the predecessors DCA.  Which later became softdesk, than was bought by AutoDesk and turned into Land Desktop, later to be rewritten into Civil3D.  

We used fieldbook files up until about 2015 when we got our first tsc2 with access then switched to TBC for all our processing.

I've closed many a traverse with them. 

 
Posted : August 20, 2022 9:33 pm
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not my real name
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I use least squares in Autodesk Land Desktop all the time for analysis. I don't adjust my traverses.

 
Posted : August 21, 2022 2:28 am
RADAR reacted
Field Dog
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Posted by: @not-my-real-name

I don't adjust my traverses.

Why?

 
Posted : August 21, 2022 7:05 am
Murphy reacted
not my real name
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@field-dog 

If the error is significant, as the least squares analysis will indicate, then I would go out to observe that measurement again.

 
Posted : August 21, 2022 7:26 am
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Rover83
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@not-my-real-name 

Obviously for a basic traverse and good procedures, the values won't change all that much, but when you say you don't adjust, yet use least squares analysis, do you update station coordinates per the analysis? Or leave them alone?

Personally, I haven't done a compass rule adjustment in years. Closure reports get a cursory look but I go straight to LSA.

 
Posted : August 21, 2022 8:10 am
BulldogDrafting
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@mark-mayer this is what I have heard from pretty much everyone who uses CAD

 
Posted : August 21, 2022 8:12 am
not my real name
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@rover83 

Hi, I look over the analysis to see how much the coordinates would be shifted if adjusted. Then I leave them alone.

 
Posted : August 21, 2022 8:30 am

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not my real name
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@bulldogdrafting 

I tried Google for that, and did not find anything resembling that comment. I attended formal training when I started, and I still believe it was well worth the time and expense. These days there is You Tube, and many videos there are helpful.

Places that I have see struggling to use software for it's intended use were the types that refuse education, thought software should be intuitively obvious, or were using pirate versions having no access to technical advice.

Some had just one person who had "figured it out" and was teaching others in a completely wrong fashion with disastrous results. Anyway, I find it hard to believe that there isn't anyone that can use least squares analysis in Autodesk products, and I will offer myself as contradictory evidence.

 
Posted : August 21, 2022 9:00 am
Field Dog
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@not-my-real-name 

I'm not at all familiar with least squares or least squares adjustment programs. I work strictly in the field, and we'd use whatever adjustment program is in our data collector, if necessary. You wrote, "If the error is significant, as the least squares analysis will indicate, then I would go out to observe that measurement again." I'm used to using old-fashioned analysis, like seeing if I had a short backsight where a significant error occurred, or if the line of sight was low to the ground and was affected by microclimate. We still check our traverse closure using (N - 2) × 180°. I'm reading through https://surveyorconnect.com/community/surveying-geomatics/lsq-transit-compass-crandall-adjustments/ to further educate myself. Thanks for posting!

 
Posted : August 21, 2022 10:04 am
Murphy
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When I purchased Star*Net, my thoughts were on the adjustment aspect.  At that time, I didn't have control of the equipment or methods of all field crews, so I wanted a better adjustment than compass rule.  After a couple of months, I learned that the actual adjustments weren't  as valuable as its ability to quickly isolate errors, correctly combine various types of survey data, and provide a template in which I can describe the fieldwork.  Photos of field books are great, but having a brief explanation of the what-where-how in one place helps when you revisit a long dormant project.  I've played around with various adjustment software and have yet to find one that holds a candle to Star*Net.

 
Posted : August 22, 2022 3:54 am

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