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Traverse Closure

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(@mm255)
Posts: 5
Member
Topic starter
 

Hey guys, attached are pictures of my unadjusted and adjusted traverse report. Was wondering how good this is but mainly whether it is worth it to run it again or if that's about as good as it will get.?ÿ

Running a Trimble S5 Robot and two-35mm Trimble traverse kits leapfrogging.?ÿ?ÿ

?ÿ

Not sure if the images will come in (1st time trying it)?ÿ

But before it was adjusted:?ÿ

Angular closure 0 0 06"?ÿ

Precision 1: 73885

Distance: 0.05?ÿ

Elevation: 0.004

After adjustment (compass)?ÿ

Angular 0"

Precision: 1:181711

Distance: 0.02

Elevation: 0.004

?ÿ

Thanks in advance

20190529 113844
20190529 113856
 
Posted : May 29, 2019 9:13 am
(@mag-eye)
Posts: 176
Member
 

Nice work. Good to go.

 
Posted : May 29, 2019 4:06 pm
loyal
(@loyal)
Posts: 3735
Member
 

Old adage:

A good traverse doesn't gain much (if anything) from adjustment.

No amount of adjustment will fix a bad traverse.

You got a GOOD one there.

Loyal

 
Posted : May 29, 2019 5:05 pm
(@steven-metelsky)
Posts: 277
Member
 

As?ÿ a professional: How did you do the traverse? How many observations? Can you confidently say that you could repeat that error if you ran it again? The point of adjusting the traverse is to see if you fall within confidence levels and the chi squared test. If you hit those marks, you're good.

Personally, you could adjust and then turn one setup ten times. You will never hit the adjusted angle, but you will be within the tolerance of that angle. You are fine with the traverse as-is.

I'd only adjust it if the scope of work called for it to be adjusted IE ALTA/NSPS Surveys just so you had it for your records

?ÿ

 
Posted : May 29, 2019 5:21 pm
(@lookinatchya)
Posts: 133
Member
 

We used to run Wild T-2's with top mount EDM's. 4 sets?ÿ , DDRR. Shot distances 5 times fore sight and?ÿ 5 times back sight for a total of 10 measurements on each leg. 1:100,000 precision was expected. Had one that was 1:200,000.

 
Posted : May 29, 2019 5:30 pm

(@mm255)
Posts: 5
Member
Topic starter
 

Monuments were set before we got to the site by another company. We were given coordinates (SPC and Local) on them and pretty much asked to check everything and set some intermediate points to build off in the future. Only two were inter visible so I occupied one, back sighted the second and saw a .0.04 distance error. I then measured that same point and held the new coordinate for my traverse. After that I measured rounds (3 sets, each set taking 10 observations direct and reverse). 

On these types of projects line of sight becomes an issue constantly so we resect a lot. Knowing this I did kind of a worst case scenario after running the traverse and resected between two points from a poor angle and checked points that were in my traverse but intentionally left out of the resection. Everything checked in the thousandths. Tomorrow will be the level loop around site.

I was debating whether to run the traverse in the opposite direction and then average the coordinates but I'm not sure if we will even have the time to do that. 

Side note: the day before we ran it I ran the adjustments on my total station l (compensator calibration etc.) And then adjusted my back sight kits to match my total station as close as possible making sure the bubbles and optical plummet all matched. 

 
Posted : May 29, 2019 5:41 pm
bill93
(@bill93)
Posts: 9838
Member
 
Posted by: Loyal

Old adage: A good traverse doesn't gain much (if anything) from adjustment.

The closure error, even if small, has to go somewhere.?ÿ It seems better to distribute it by adjustment than to leave it all in one leg.

 
Posted : May 29, 2019 6:00 pm
loyal
(@loyal)
Posts: 3735
Member
 

Bill

True!

But no matter how you smear the 6" and .05' around, it doesn't really benefit the intermediate positions all that much. (of course I would adjust too, just saying)

Loyal

 

 
Posted : May 29, 2019 6:12 pm