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Calibration Base Line

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(@loyal)
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A friend (on the left in the photo) just sent me this picture of us on the Salt Lake Lake NGS Calibration Base Line (circa 1976).

To tell you the truth, I have no recollection of that day (Senator)!

I DO however remeber that T-16 and AGA Model 76 very well.

🙂
Loyal

 
Posted : May 22, 2011 6:21 pm
 RADU
(@radu)
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Still have my top of instrument mounted AGA.

Must check the model when I get to it in back of the shed. I guess a museum piece now.

Purchased it new around 1979. Sat on a Zeiss 10 second instrument or the 1 second.

Sadly can not recollect the last time I used it. Got "dumped" when Mr Leica introduced his total station that recorded measurements in 1990.

Loyal our hair lengths were comparable for '76. Mine was possibly a tad shorter ,but bushier...LOL

RADU

 
Posted : May 22, 2011 6:38 pm
(@loyal)
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Still have my top of instrument mounted AGA.

I still have that hat, but no hair to put under it!

🙂
Loyal

 
Posted : May 22, 2011 6:58 pm
(@ridge)
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Still have my top of instrument mounted AGA.

Out by Point of the Mountain.

I wonder if the baseline survived all the new freeway construction? I checked something out there, can't remember what.

 
Posted : May 22, 2011 7:22 pm
(@loyal)
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Leon

It's TOAST!

Been toast for YEARS! For a while there were still a couple of intervisable piers, but I'm pretty sure that they are all gone now.

Loyal

 
Posted : May 22, 2011 7:25 pm
(@dave-karoly)
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Loyal

I had no idea you were an outlaw Country singer LOL.

😉

 
Posted : May 22, 2011 7:26 pm
(@john-hamilton)
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piers

That is the way a baseline SHOULD be built, with piers. None of the ones in PA (nor any others that I know about, use piers (pedestals). Other countries often do, though. Eliminates centering error, and is, I think, a much better way to do it. I believe the aussies constructed all of theirs with piers, right Richard?

 
Posted : May 23, 2011 1:23 am
 RFB
(@rfb)
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Man, you guys did have it rough back then!

There is NO WAY I could haul that tripod through the woods!

:coffee:

 
Posted : May 23, 2011 3:25 am
(@kieran-mckeon)
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piers

Correct, in Australia we use concrete pillars on a concrete slab. They can be few and far between but I know of a good one not too far from home that overlooks a beach.

 
Posted : May 23, 2011 4:00 am
(@dave-ingram)
Posts: 2142
 

To piers or not to piers - that is the question

The comment above about the advantage of having piers on a CBL is valid, but it is also perfectly valid to NOT have piers so that you are testing your entire system under (somewhat) realistic circumstances. I have been to the SLC CBL many years ago and found it quite impressive and given the state of equipment at the time it was established it was probably the best way to go.

However, today's EDM's are so refined that if they measure they are measuring correctly. The variables are the set ups and all the auxiliary equipment. By using your tripod(s), range poles, prism holders, etc etc you can verify your entire system.

There is a place for both, but with today's equipment I would prefer to not have piers.

OK - take your best shots at rebuttal.

 
Posted : May 23, 2011 4:10 am
 RADU
(@radu)
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Thart is correct John, BTW R U back in the states already?

RADU

 
Posted : May 23, 2011 6:13 am
 RADU
(@radu)
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RFB ... EASY as NO trees in SOZ... LOL

RADU

 
Posted : May 23, 2011 6:15 am
(@adamsurveyor)
Posts: 1487
 

> To tell you the truth, I have no recollection of that day (Senator)!
>
> I DO however remeber that T-16 and AGA Model 76 very well.
>
> 🙂
> Loyal

LOL....sounds like a surveyor.

(by the way, I agree that the piers are good, but it isn't a bad idea to set up tribrachs and a tripod over a point. I think a lot of crews are negligent in keeping their tribrachs in adjustment, and abilities to set up tripods. Maybe that shouldn't be a factor, but then again maybe it should. That tells what kind of precision and accuracy you should be able to expect with that crew and that equipment.)

 
Posted : May 23, 2011 6:28 am