The trig pillars that helped map Great Britain

Wonderful photos and a rich surveying history in my old motherland. Thanks for sharing.

Wonder if they had named the Hotine Oblique Mercator projection after Brigadier Martin Hotine ?

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

I'm an occasional Trigpointer! http://trigpointing.uk&apos ;">trigpointing.uk

Wished we had the http://www.ngs.noaa.gov/OPUS/&apos ;">OPUS system in the UK though.

wilba, post: 368697, member: 9024 wrote: I'm an occasional Trigpointer! http://trigpointing.uk&apos ;">trigpointing.uk

Wished we had the http://www.ngs.noaa.gov/OPUS/&apos ;">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

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.

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

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.

Here is one from yesterday's job site