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Least Squares Adjustments

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(@chief)
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Can anyone point me to some resources for teaching myself how to do LSA? I use Leica LGO and Viva Data collectors. Our office mostly still deals in Compass Rule for traverse but I would like to learn how to do the LSA. Thanks in advance for the help!

 
Posted : 28/04/2015 11:48 am
(@dave-lindell)
Posts: 1683
 

"Adjustment Computations, Spatial Data Analysis" by Ghilani & Wolf (Wiley)

 
Posted : 28/04/2015 12:20 pm
(@norman-oklahoma)
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Have you done any LS in other software before? Are you using LGO for other things?

I was thrust into a situation a few years back where I needed to figure out how to do adjustments in LGO. I used my experience in Leica SKI, TGO and StarNet, together with some input from others in the office on how to do basic import and data edits in LGO, and figured it out fairly quickly.

Basically you import your data into LGO, then go to the Network module and click "Adjust". By selecting points on the screen you can set points to be held or not, and modify the coordinates of your held points. There is more you can do but that should get you started.

It's not as flexible as StarNet. As a matter of fact, if you haven't done LS before, it might be valuable to download the 10 day demo of StarNet and try that out first.

There are some YouTubes, have you checked those out? And the salesman that sold you LGO should be able to provide some training.

 
Posted : 28/04/2015 12:35 pm
(@dmyhill)
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> Can anyone point me to some resources for teaching myself how to do LSA? I use Leica LGO and Viva Data collectors. Our office mostly still deals in Compass Rule for traverse but I would like to learn how to do the LSA. Thanks in advance for the help!

I do not know how use the Leica stuff (I assume it does LSA, SKI-Pro did), but every program I have used that uses least squares walks you through how to do it. The why and what is happening is found in the book above. It may not matter much to you about the text book stuff, but some education in what is happening is useful for reading the reports and analysis generated by the software.

And, I believe that StarNet is worth every single penny that you spend for it.

 
Posted : 28/04/2015 12:38 pm
(@jim-in-az)
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"And, I believe that StarNet is worth every single penny that you spend for it."

I believe it was worth far more than I paid for it. There's nothing like tweaking things and watching what it does to the adjustment - it is an incredible learning tool!

 
Posted : 28/04/2015 12:53 pm
(@chief)
Posts: 25
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Thanks for the quick replies. I am not in charge of adjusting anything as I am just a lowly licensed party chief. I am just going to figure it out because I think it can solve some problems we are having. I havent even touched LGO as I dont even have a copy on my computer, but we will get it all squared away. I have to be able to have a competent argument to be able to push for something like this and have some idea what I am talking about. Having alot of trouble traversing between GPS pairs with decent closures and I think this could help us from some discussions i have read here. Wish me luck!

 
Posted : 28/04/2015 4:23 pm
(@dmyhill)
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Download StarNet, and go through the tutorial. (I think it should work in demo mode.) Either way, the help and in-software documentation
is very helpful.

 
Posted : 28/04/2015 5:15 pm
(@big-al)
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If you're using Carlson Survey in the office, I believe you may have Carlson's SurvNET program included. I've been using it for a couple of years now. It was hard to get the hang of it, but now that I have, I wouldn't go back. It's amazing!

 
Posted : 28/04/2015 6:20 pm
(@geeoddmike)
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Also consider reviewing the materials at http://bestfit.com/old/freedemo.shtml

They include a demo version as well as videos and documentation for the Columbus software package.

As others have recommended, the Wolf/Ghilani textbook as well as his software developed to support the book are recommended. It is the standard textbook used in most undergraduate surveying computation classes. Dr Ghilani had a web site named "Free Goodies" that had links to his statistics, adjustment and matrix applications.

BTW, do a search on this site for the TRIMNET package documentation (Trimble). Someone at some time posted a digital version for free download. I thought it was very well done.

Good luck,

DMM

 
Posted : 28/04/2015 6:58 pm
 abw
(@abw)
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Don't read this one if you're in a bad spot or having suicidal thoughts.

 
Posted : 29/04/2015 4:12 am
(@jim-in-az)
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" I am just a lowly licensed party chief."

These are the most valuable folks in our operation - none are "lowly"...

 
Posted : 29/04/2015 7:23 am
(@moe-shetty)
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> Don't read this one if you're in a bad spot or having suicidal thoughts.

I am curious why you might state such a thing: the Ghilani book covers a great deal of ground, AND comes with a very effective LSA program, transformations, GPS vector adjustments, etc.

 
Posted : 29/04/2015 7:44 am
(@makerofmaps)
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I about fell out of my chair. Good book. What was it one of my professors said? Good bathroom material. I'm not knocking on the book.

 
Posted : 29/04/2015 8:36 am