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Calibration Baselines...how many go regularly?

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(@geeoddmike)
Posts: 1556
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@jalbrz?ÿ

Posted previously on this thread was a link to the Canadian approach.?ÿ

Have you seen this: https://www.ijser.org/researchpaper/A-convenient-procedure-for-the-calibration-and-check-of-GNSS-systems-by-using-the-relative-static-positioning-method.pdf

i am wary of the comprehensive approach while accepting that the best test of a GNSS is its ability to meet a standard. I do not know how those creating GNSS processing software validate its performance. I suspect that they do not include all the modeling performed by GAMIT, GIPSY, Bernese and PAGE-NT. Nor do they likely follow the IERS Conventions.

This idea was discussed by folks at NGS like Dr Mader and Mr Hilla. I do not know whether any of it was documented.

My 0.02ƒ?ª

 
Posted : 12/05/2022 2:56 pm
(@john-nolton)
Posts: 563
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@jalbrz?ÿ ?ÿI was about ready to post some information and GeeOddMike beat me to it. Look at the paper he poster under the?ÿAbstract and you will see ISO 17123-8

Everyone should read this. Also?ÿGIM International?ÿ?ÿhas a 2 page?ÿARTICLE?ÿon "A Modern Calibration Bench: Calibrating Survey Instruments

One last remark; you said "Oh, and @RobertUSA myself and at least one other advisor have been mumbling internally that we ought to provide a "GNSS CBL" of sorts, that would..."?ÿ?ÿWell you are so young you do not remember that in the early days just something like this did exist. See "Report on Test and Demonstration of Macrometer Model V-1000 Interferometric Surveyor" this was the first commercial geodetic GPS unit on the market. This report was from the OLD FGCC (I think it's now FGSC) done in May 1983.

The test network was done in the Washington D.C. area. "The distances were from 186 meters to 1.3 km for short base lines and 8.7 to 42.1 km for medium length base lines"

This might help you in your present day endeavor.

JOHN NOLTON

PS?ÿ ISO 17123-8:2015 Part 8 is GNSS field measurement systems in real-time kinematic (RTK).

 
Posted : 12/05/2022 3:42 pm
(@john-nolton)
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In my above post I have 2 letters turned around It's?ÿNOT?ÿ FGSC;?ÿ It's FGCS

Federal

Geodetic

Control

Subcommittee

 
Posted : 12/05/2022 5:34 pm
(@geeoddmike)
Posts: 1556
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Most of the FGCS reports (some are archived) are available here:

https://www.ngs.noaa.gov/FGCS/instruments/reports/

The program ran from 1983 to 2001. The V-1000 report is archived.?ÿ

The earliest report is:

F5DA7B1F 12B8 40D0 BAEC 98FC5A08FDF1

Early days of GPS with an incomplete constellation, poor orbit accuracy, no phase models, no fixed tripods, and NAD83 not yet implemented.

These are the instruments tested:

659225AC 6682 4DDC B306 04DCBC10AA73
 
Posted : 12/05/2022 10:16 pm
(@bushaxe)
Posts: 645
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I frequent a CBL about an hour from me a few times a year prior to deformation surveys. Its setup a long the side of a runway at a small airport. I call the airport manager a few days ahead of time to get a day of good weather and low activity.?ÿ
I like overcast days, but I still take a popup tent to shade the instrument. I have a set of high precision Leica prisms that I run through the paces on every station, forward and backwards. I observe my temperature and pressure at the site with a handheld weather station before each prism set. I compile all of this information using calibrat. The instruments are serviced annually but are also run through the Leica calibration routine before a CBL visit if it hasnƒ??t just returned from the service center.?ÿ

 
Posted : 13/05/2022 3:28 am
(@jalbrz)
Posts: 57
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@geeoddmike The only problem with building a toolset based on the method described in that paper is... no one will use it!?ÿ

Why? The amount of field time, like a full check using one of EDMI CBLs, is seen to most as unwarranted or not worth the investment.

 
Posted : 13/05/2022 10:10 am
(@jalbrz)
Posts: 57
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@john-nolton?ÿ

Even though you feel the need to poke fun at my age, I will respectfully refrain from making any old age jokes.?ÿ Suffice to say that I, nor many young people, are ignorant to everything that occurred before we entered our professions/careers.?ÿ Is this what people mean when they say they are encouraging younger people to enter this profession??ÿ Hit 'em with below-the-belt jabs when they step in to simply put information closer to people's fingertips?

FYI, I've got a copy of FGCC-IS-83-2 sitting on the floor next to my chair right now, photo attached.?ÿ

And what I'd like to see are bunch of mini networks, not one set of 8 stations in/around DC.?ÿ The whole point of this would be a method of system verification for our constituents; an effective, efficient way of verifying hardware, software, methods, even non-NSRS networks.?ÿ But with modernization efforts currently undergoing some re-prioritizing, I don't foresee an OPUS-based "GNSS CBL" anywhere in the near future.

photo
 
Posted : 13/05/2022 10:38 am
(@jalbrz)
Posts: 57
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@bushaxe Hey, good to hear you're out there keeping' your gear in tip top shape!?ÿ You ever look at our replacement for CALIBRAT??ÿ It's totally different, but named CALIBRATE.?ÿ It takes more setup, but it's pretty slick.?ÿ Drop me a line if you ever wnat to look into it, I talked to Mack and his folks at LRH about it, but they didn't get to use it last year as I discovered a problem with it that prior week!?ÿ It has been fixed/updated now, here's a link: https://geodesy.noaa.gov/PC_PROD/CALIBRATE/#

 
Posted : 13/05/2022 10:44 am
(@john-nolton)
Posts: 563
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@jalbrz?ÿ ?ÿSorry to hurt your feelings. It won't happen again; I assure you of that.

 
Posted : 13/05/2022 12:04 pm
(@jalbrz)
Posts: 57
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Hurt feelings, no. But it is annoying hearing that sort of comment from my elder mentors, often the same folks hoping to preserve & grow this profession.?ÿ I guarantee that it's run off some interested and capable candidates... but not me.

 
Posted : 13/05/2022 1:21 pm
(@dougie)
Posts: 7889
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GIF
 
Posted : 13/05/2022 1:52 pm
(@bushaxe)
Posts: 645
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Posted by: @jalbrz

@bushaxe Hey, good to hear you're out there keeping' your gear in tip top shape!?ÿ You ever look at our replacement for CALIBRAT??ÿ It's totally different, but named CALIBRATE.?ÿ It takes more setup, but it's pretty slick.?ÿ Drop me a line if you ever wnat to look into it, I talked to Mack and his folks at LRH about it, but they didn't get to use it last year as I discovered a problem with it that prior week!?ÿ It has been fixed/updated now, here's a link: https://geodesy.noaa.gov/PC_PROD/CALIBRATE/#

Good to know. Thanks

 
Posted : 14/05/2022 1:07 am
(@bpowell)
Posts: 2
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just downloaded Calibrate.exe.  how do i get data to the .tra file it needs.  i have baseline data stored for another software.  not sure how to get it into calibrate.

 
Posted : 17/05/2023 12:24 pm
(@bpowell)
Posts: 2
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@jalbrz got any instructions for use?  i have baseline data but cant figure out how it get calibrate to read it.

 
Posted : 17/05/2023 12:30 pm
(@geeoddmike)
Posts: 1556
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I don’t know whether Jalbrz monitors this site. His contact information is found on this webpage:

https://geodesy.noaa.gov/ADVISORS/index.shtml#Great%20Lakes

He is the NGS Advisor to the Appalachian region.

 

 
Posted : 17/05/2023 10:31 pm
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