I have been using a new TSC3.
When using RTK and TSC2, I often calibrated to known coordinates, and my calibration screen would tell me how far "off" my rtk observations were between two points - meaning I would hold one coordinate, and the second point would be close but not perfect.
Using what I thought were the same properties and set up on my TSC3, I can't seem to work the same way: instead, I get both calibration points as "exact same". This seems forced, and is not how I want to work.
Thanks in advance for any and all advice on how to calibrate with TSC3.
Just a thought.... is it adjusting the scale factor to "fit" the two points??
There's a check box in the Survey Style that says Set Scale To 1; my guess is it's checked on one and not the other. If it's unchecked it scales the GPS to fit the ground coordinates; this is the default.
I'd suggest that you download the General Survey Help file; TIM will link you to it (the info circle next to GS), so will this link:
http://www.trimble.com/Survey/Trimble-Access-IS.aspx
Go to Downloads and then Help Files and Release Notes.
Any 2 points will make a line, therefore you won't show any residuals for either H or V. Add a 3rd point you will see H residuals but not V, why? Because any 3 points will make a plane. Add a 4th point and you will see V residuals as well. Been the same in TSC2 TSC3 all along.
what makes me nervous is getting "zero residuals" with two points, when I know there is a small residual. On my own previously adjusted sites, I don't see why I need to go to three or four points, which I did not have to do with the TSC2. Therefore, I'm following L Dee's suggestion - that sounds like where I need to go.
There won't be a residual with 2 points. Not if youre calibrating. You are forcing the project to scale to those points. If you have 3 you can't have the exact scale between all 3, therefore you get a residual. If you are thinking you want a scale factor or 1.00000000 yes you will have a residual, but calibrating will ignore the scale factor setting of 1.0000. Dont have RTN yet in my area, so I've calibrated literally 100s of jobs....
I'm missing a togle. with my TSC2, on a daily basis, I would calibrate onto a known site. After two points, there would be a residual. my two known points were not exact distance as measured with RTK. I calibrate onto the first point, shoot the second point, and the actual difference between known points and measured RTK would show up as a residual. .01, or point 02., never 0.0000. I tried the above suggestion but the same thing is happening. If the TSC3 will not show residuals as the TSC2 did, I just need to know.
i just checked my TSC2, and there are several 2-point calibrations that show a residual for the second point. all the set up is identical to my TSC3 settings. so, I'm stumped.
A two point calibration should show residuals. I would imagine it would also reproject your file each time it is calibrated
I don't know about older versions of SC, but I don't remember either SC or Access ever showing residuals for a two point calibration. To prove this, I just grabbed a tablet running Access 2016.00 (current release) and keyed in Global coordinates 30 00 00N 90 00 00W and 30 00 10N and 90 00 00W. I then keyed in grid coordinates 5000,10000 and 5100,10000 and calibrated to those pairs. See below.
Lee D, post: 369813, member: 7971 wrote: I don't know about older versions of SC, but I don't remember either SC or Access ever showing residuals for a two point calibration. To prove this, I just grabbed a tablet running Access 2016.00 (current release) and keyed in Global coordinates 30 00 00N 90 00 00W and 30 00 10N and 90 00 00W. I then keyed in grid coordinates 5000,10000 and 5100,10000 and calibrated to those pairs. See below.
What's the scale factor on your example project??
Scale factor is 0.09898582.
I don't see how a residual could be calculated with 2 points unless you already had a scale factor applied. Even then your residual would just show the distance error.
I always have the scale factor set to 1 just for that reason. If you allow that to float, you will never get residuals on a (two point) line.... but more importantly, it will apply that scale factor to Everything else you measure. That is where you can get really screwed up.
Lee D, post: 369824, member: 7971 wrote: Scale factor is 0.09898582.
Now if you force the s/f to stay at 1, you would get residuals and you would know right away that something was wrong.
I tried it both ways - with and without Set Scale to 1 checked. Per Trimble's literature, the Set Scale to One holds the GPS distances over the calibration point distances and should be used in a case where you believe the GPS to be more precise than the points you're calibrating to. But you still don't get residuals with only two points.
In any case this is interesting as a purely academic exercise but with all due respect I would never calibrate to two points in the real world.
Lee D, post: 369831, member: 7971 wrote: In any case this is interesting as a purely academic exercise but with all due respect I would never calibrate to two points in the real world.
yes, agreed on that for sure!
Is it possible to set the scale factor to the proper geodetic combined factor instead of 1?
A calibration would set its own scale. A calibration should always be done using static data, then once done to acceptable limits never, never redone to a file.
