Notifications
Clear all

Collimation correction and DIN 18723

8 Posts
6 Users
0 Reactions
6 Views
(@brendan8761)
Posts: 6
Registered
Topic starter
 

Just wondering if anyone had insight into Trimble robotic stations and there collimation corrections.
The instruments are spec'd to DIN 18723, which (as I understand it) defines the standard deviation of an instrument based of a full set of angles (direct & reverse).
With my new instrument(SPS610) and software(LM80) I am told that there is no need to double in angles and in fact the software does not allow for it.
So my question becomes how does the electronic collimation correct fit with the DIN 18723 spec.

 
Posted : April 30, 2012 5:30 pm
(@wildt2)
Posts: 207
Registered
 

You can do the whole set of DIN 18723 observations if you want to, no problem. The collimation correction has nothing to do with DIN 18723. That capability was included so that you can make Face 1 (or Direct) only observations and still achieve excellent vertical repeatability.
For example let's say you want to as-built a railroad track. After performing the collimation, your rail shots will be consistent vertically without having to change the instrument face for every location. See?

 
Posted : April 30, 2012 6:07 pm
(@ralph-perez)
Posts: 1262
 

Isn't that gun used primarily for machine control?

 
Posted : April 30, 2012 6:07 pm
(@brendan8761)
Posts: 6
Registered
Topic starter
 

I am new to the trimble family of instruments, but yes I believe it is used for machine control and with Building Information Management. The LM80 software is designed only for use in building layout.

 
Posted : April 30, 2012 6:44 pm
(@paul-in-pa)
Posts: 6044
Registered
 

Direct Only Does Not Meet DIN 18723

End of story.

Robots are fantastic at repeatability. Repeatability is not in the DIN 18723 specs, but precision is.

Paul in PA

 
Posted : April 30, 2012 6:56 pm
(@surveythemark)
Posts: 365
Registered
 

Can you explain who told you ..."I am told that there is no need to double in angles"

Salesman? Trimble Tech Support?..... Anyone with any education, experience or professional credentials?

I perfect instrument??? Wow. I did not know anyone built a perfect instrument.

 
Posted : April 30, 2012 7:04 pm
(@norman-oklahoma)
Posts: 7610
Registered
 

> .....I am told that there is no need to double in angles ....

IF your gun is properly collimated, and IF there is nothing causing the sighting to be less than perfect at the critical moment and IF you don't happen to get one of those 5% outliers then MAYBE you don't need to double. But how do you prove, from the data, that all those things are true if you don't? So I think you are quoting salesman speak. And no matter how good the single shot data may be, doubled data will, generally, be better.

That said, you will get very good topo results with a gun like this with just a moderate amount of care and attention.

 
Posted : April 30, 2012 7:14 pm
(@brendan8761)
Posts: 6
Registered
Topic starter
 

Yes it was a salesman that told me that doubling angles was not required, although I got the impression that he did not understand what a set of angles were, nor a resection, and obviously had no concept of error propagation. I tried to enlighten him on the concept of error ellipses and error propagation after he stated that the 5" instrument with a 360 prism could set anchor bolts within 3mm(1/8"), across my fairly large site and all I needed was two control points and the software would do all the rest.
But more than the failings of the local Trimble staff it is the software LM80 that does not allow for observations in F2. When I first received the instrument I did a trial resection to see how it performed and how it reported the standard deviation of the position, I went to observe the target in reverse scope and was prompted that the observation could not be made on that face.
This seem to be the way Trimble is going, dumbing down there software to be used by trades people(no offense meant, I am a journeyman carpenter as well as a geomatics technologist). The LM80 software does not allow for turning sets of angles, has very limited COGO abilities and I am informed by Trimble that the data collector(Nomad) can only run one program, therefore having Survey Pro on board also is not possible. Despite these failings this robotic station/software package is becoming the norm among general contractors in the area for it obvious ease of use, but I am concerned of the ramifications of telling contractors that this is all the need to eliminate the need for a professional surveyor.

If any one has experience with the LM80 software I would appreciate hearing about it.

 
Posted : May 1, 2012 1:32 pm