Static to Localized Coordinate System

James Suttles

Active Member
I need to static 6 points and incorporate those points into a localized system that is on the LS. I plan to static the points (2 hours) and send to Web DPOS, then import those points to the localized coordinate system on the LS.

Is this the easiest way to get those static observations onto the localized coordinate system? If not, what are the options. Below are the residuals of my localization. The CPXX are the coordinates provided on the plans and the CPXX_fnd are points located by the LS, using the NCRTN. The collected points were 480 second observations, with 6 engines fixed. Plans state the points are localized, and from the LS's localization it appears they are ground distances. The vertical is listed as NAVD29, so those factors are what are to be considered with the new points.

CP15 and CP11 appear to have a vertical issue. I have located both of those points multiple times and the elevation on those points does not come anywhere close to what is published. I have ran a differential level through a few other benchmarks on the site, and I am finding 0.20' vertical inconsistencies on 2 of 3 benchmarks found. Plus the amount of error in CP15 and CP11, looks to be odd.

So is my 2 hour static session overkill, considering the localization was RTK with NCRTN? Would it be adequate to occupy the 6 new points with 480 second observations, on the Localized coordinate system page?

The end results will be for Trimble Machine Control Calibration, on 14K feet of New Sanitary Sewer Outfall. Curious as to what would be the best procedure to obtain the best consistency for the new points.


00868_Localization_20180606-10.41.51.png


Thanks
 

Shawn Billings

Shawn Billings
5PLS
Did you send the base for your local points to DPOS? If so, then you also need to go into localization after performing DPOS on the base. The localization will be recalculated automatically using the CORS determined coordinates for your underlying system (i.e. true State Plane Coordinates). Now your local system is directly tied mathematically to the CORS. To input the static points, simply switch the coordinate system to State Plane, import (or manually enter) the static points, and switch back to your local system if desired.
 

Shawn Billings

Shawn Billings
5PLS
I reread your post and see that your local system is tied to CORS via NCRTN. In this case, there is no base to send to DPOS and no need for it. Switch to State Plane, enter the static points and switch back to local if desired.
 

James Suttles

Active Member
Thanks, do you think the Static sessions are overkill, considering the Localization was done with RTK ( 8 min occupation, 6 engines, with verify). Would it make sense to collect the new points with RTK or use the Static Session, (2 hours).
 

Adam

Well-Known Member
5PLS
Pretty dang good residuals except for the two vertical outliers. Still If you have to back it up static is better than rtn. Rtk/ppk from your LS base is better than rtn. All because of dpos reports. You have some documentation. Ncrtn you have nada.
 
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Jim Frame

Well-Known Member
Ncrtn you have nada.

On the contrary, with RTN shots (as with RTK shots) you have the vector record (delta X Y Z and their standard errors) and correlation/covariance values, as expressed in the g-file. The g-file isn't as user-friendly as a DPOS or OPUS report, but it contains all the information necessary to evaluate the quality of the vectors and incorporate them into a least-squares adjustment if you have the software to make use of it.
 

Adam

Well-Known Member
5PLS
True, I don't think Doug is doing a least squares adjustment on his project.
 

James Suttles

Active Member
So the consensus is an LS and LS base, through any new points, is as adequate or accurate as a Static Session? I know that maybe a hard question to answer.

Its just that the localization file was created with RTK/RTN, and not Static, so is Static Overkill, or necessary to obtain the best possible control for the Client who will ultimately use these points in his Machine Control Calibration?
 

Joe Paulin

Well-Known Member
Your calibration posted above looks very tight to me, especially for the intended use - machine control, ie moving dirt.
 
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