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The trig pillars that helped map Great Britain

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tyler-parsons
(@tyler-parsons)
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Interesting article in BBC News about the survey of Great Britain.

The trig pillars that helped map Great Britain

 
Posted : April 21, 2016 5:28 pm
Williwaw
(@williwaw)
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Wonderful photos and a rich surveying history in my old motherland. Thanks for sharing.

Just because I'm paranoid, doesn't mean they aren't out to get me.

 
Posted : April 21, 2016 7:11 pm
rj-schneider
(@rj-schneider)
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Wonder if they had named the Hotine Oblique Mercator projection after Brigadier Martin Hotine ?

 
Posted : April 21, 2016 8:00 pm
geeoddmike
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For those mathematically inclined, Hotine's Mathematical Geodesy is available on-line at: https://archive.org/stream/mathematicalgeod00hoti#page/n5/mode/2up

BTW, see this example of a South Texas pillar monument:

https://picasaweb.google.com/106803290884381691323/MissionAransasNERR#5236227289684171586

The design and construction was performed by the NERRS staff (part of NOAA) and was intended more as a PR exercise than for surveying. It does have a high accuracy position. Datasheet is: http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=DK7860

 
Posted : April 22, 2016 12:38 am
wilba
(@wilba)
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I'm an occasional Trigpointer! trigpointing.uk

Wished we had the OPUS system in the UK though.

 
Posted : April 22, 2016 3:22 am

geeoddmike
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wilba, post: 368697, member: 9024 wrote: I'm an occasional Trigpointer! trigpointing.uk

Wished we had the OPUS system in the UK though.

I hope you are aware of other automated processing tools. Some I've used at linked here:

http://geodesyattamucc.pbworks.com/w/page/13931102/FrontPage#Lab5AutomatedGPSProcessingToolsbeyondOPUSdue27March2013nbsp

It is my understanding that OPUS positions cannot be provided for points in some countries due to their failure to agree with such a service being provided there.

HTH,

DMM

 
Posted : April 22, 2016 7:29 am
geeoddmike
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BTW, came across some surveying pillars in the vicinity of the Sydney Opera House. See: https://picasaweb.google.com/106803290884381691323/GeodesyRelated#5212878396094071282

While on a hiking trip in Ireland more than a few years ago, I did happen to come across some of the Ordnance Survey pillars on some coastal islands with great views.

 
Posted : April 22, 2016 9:38 am
john-hamilton
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Pillars are great. I really admire the UK for having established those.

Many (most) of the 39 USACE dams we monitor have pillars. I started out surveying at the USACE 35 years ago on these projects, and I thought pillars were normal!

I have a pair on my property, which I have posted photos of before, which I use for testing, calibration, etc.

I found a survey pillar while wandering alleys in Cairo, Egypt. I thought I had a picture of that, but cannot find it.

I used a nice one in Canada last year.


It had a BM on the side

and also a steel loop on the other side to lock equipment to

 
Posted : April 22, 2016 9:43 am
pdop 1.0
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South Africa has great trig network, and whilst it has been replaced some what by VRS , I still use it daily to resect off. Nothing like coming off two dropped in GPS points and two trig beacons to tighten the solution up and know you have got a great fix.

Here are some of the trig beacons my brother and I have visited. You can see many cool shots on Instagram using the #trigbeacon.

 
Posted : April 24, 2016 3:55 pm
john-hamilton
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Here is one from yesterday's job site

 
Posted : April 28, 2016 6:27 pm