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(@rankin_file)
Posts: 4016
Topic starter
 

control verification survey may not be correctly constrained?

eidt- to clarify- this is a metric project...

 
Posted : July 14, 2014 9:27 am
(@ryan-versteeg)
Posts: 526
 

> control verification survey may not be correctly constrained?
>
> eidt- to clarify- this is a metric project...
>
>

At first glance, I agree, but the contrary may be shown.

How can those two points have been held, but the deltas show they are not held, correct? (2cm x 5cm +/-)

 
Posted : July 14, 2014 10:33 am
(@scaledstateplane)
Posts: 170
Registered
 

I think those two points are only held for Bearing, with the overall distance allowed to float (you'll notice that the deltas are equal and opposite).

 
Posted : July 14, 2014 10:39 am
(@thebionicman)
Posts: 4438
Customer
 

This appears to be the result of an 'equal weight' being assigned to the two points. I do a LOT of monitoring and control surveys and haven't had a use for this method yet...

 
Posted : July 14, 2014 10:47 am
(@john-putnam)
Posts: 2150
Customer
 

It looks like F50? and G50? were held for vertical but I see nothing to suggest that anything was constrained horizontally(other than possible the azimuth between G50? & F50?). While an unconstrained adjustment will tell you the strength of you network it does not do much good telling you how it fits the existing control. At least hold one point and an azimuth. Given the absolute value of the vectors from measured to record I would suggest that it might not fit that bad.

Just my $0.03 worth.

 
Posted : July 14, 2014 11:25 am
(@mightymoe)
Posts: 9920
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No Rankin, it's just you!!;-)

Really, it looks like a scale factor issue, how were the elevations measured? levels?

 
Posted : July 14, 2014 1:12 pm
(@gibtruck)
Posts: 14
Registered
 

Agree. Sf looks like the issue the marks don't fit better, but that may be on purpose.

 
Posted : July 14, 2014 2:36 pm
(@ric-moore)
Posts: 842
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When I was processing static survey data, typically I ran the first process holding one horizontal control point for a minimally constrained network to isolate any blunders or issues. Then I ran a fully constrained process holding multiple horizontal control points (as available) for horizontal results. Then I repeated these two steps using vertical control points as constraints.

From the looks of what you have provided, it appears that the user is holding two vertical control points constraining the unknown positions to those. May be only one step in the process, who knows.

 
Posted : July 14, 2014 3:14 pm