Talk:Triangulation station

Merger

I've been bold and merged Trigonometrical station into this article, since there was clearly no justification in having two articles on the same topic. It could perhaps do with a bit of a prune from somebody knowledgeable to remove surplus information. I did the merge this way round because this article was here first, but if "Trigonometrical station" is the more commonly used term worldwide then maybe it should be moved. --Blisco 17:53, 1 October 2006 (UTC)

I think that Triangulation Station would be the best place for this article, as this is a name that is commonly used both in North America [1] and the UK [2].

What the Ordnance Survey actually use on the key to all their maps is Triangulation Pillar - a quotation in a glossary is not necessarily a definitive statement on the correct nomenclature. Velela 20:29, 1 October 2006 (UTC)

Looking at the pictures of trig points in Australia and NZ though, I shouldn't think you could call those 'pillars'. --Blisco 21:18, 1 October 2006 (UTC)

I wasn't trying to make a definitive statement on nomenclature, I was just giving a couple of examples of usage. Triangulation pillars are only one type of triangulation station used in the Ordnance Survey's network; for example, they also use surface blocks [3], bolts [4], and rivets [5]. In the US triangliation stations are usually just marked with disks similar to this benchmark disk, but the triangulation network also included prominent buildings, points marked with bolts or rivets, and sometimes pillars. --JeremyA 22:08, 1 October 2006 (UTC)

For the record, I wasn't dissenting from the use of Triangulation station, just clarifying that relying on a glossary wasn't an appropriate justification. However, it seems a general enough term to cover most uses. Velela 10:05, 2 October 2006 (UTC)

I think Triangulation Station is the best name for this article, for whilst the pillar is the most common type in the UK there are actually 10 different types, however, as previously noted the pillar is the only type shown on the commonly available OS maps. Additionally the article page relating to the UK states that 'Many of these trig points are now disappearing from the countryside ' which is not strictly true. TrigpointingUK gives details of the 7400+ triangulation stations around the UK. Of these 6500+ are of the pillar type of which less than 1% are listed as missing. The problem I have is with the words 'many' & 'countryside'. Having trawled through the Trigpointing UK website it's apparent to me that of this (less than) 1% the majority have either been long gone (20+ years) or more recently lost to urban sprawl or motorway expansion. I don't believe the current loss of these pillars constitutes using the word 'many' - the numbers are just not significant enough. Secondly 'countryside' evokes an area that is rural, outside the urban landscape. Ok, technically speaking it might mean anywhere within a country but the common perception is aforesaid. Bearing this in mind, in my opinion, the statement once again exaggerates the current situation. I don't see any evidence that swathes of pillars are being removed from rural areas. I believe that something along the following lines would be more appropriate - 'A number of trig points, primarily pillars, are under threat predominatly due to the advance of urban sprawl and expansion of the road network'. Mac.trig 15:51, 11 July 2007 (UTC)

I've moved the page from "Trig point" to "Triangulation station" as it seems to be the consensus. —Pengo 23:49, 4 November 2007 (UTC)

New Zealand

New Zealand English uses 'trig station' as much as 'trig point'. If anything, 'trig station' is more common. — Preceding unsigned comment added by 151.226.55.183 (talk) 08:46, 18 April 2016 (UTC)

External Link: Database of trig points in the United Kingdom

No longer works 86.187.174.178 (talk) 10:15, 2 July 2020 (UTC)

A church steeple cross?

The current version Special:Permalink/1183197728 dated 2 November 2023 says in the section #France:

They can be remarkable points as churches steeple crosses [...]

Are there any sources for that? A triangulation station needs to provide a place to set up a tripod for a theodolite (in trigonometric measurement) or a positioning device above the point, as well as for a person to move around it and take measurements. How could one do that on a steeples tip? --CiaPan (talk) 08:01, 7 November 2023 (UTC)

I have not yet looked to see if this article has it's very own definition of "triangulation station" but a tall object like a church steeple can be located by geodetic survey using triangulation, and then published in official maps and databases. I tried looking at the United States National Geodetic Survey website but wasn't able to locate a 21st century publication that discusses this. An example of a church spire that serves as a triangulation station is the Baptist Church in Rutland, Vermont, which is described in an NGS datasheet.

Even though one cannot set up a tripod over such a monument, it is still useful. One can set a tripod over a nearby survey mark on the ground with known horizontal coordinates, and then sight the church spire to establish a horizontal direction. If all that is available are several spires, one can set up a tripod over a mark that doesn't have known position, site the spires, and use a mathematical procedure known as resection to compute the location of the unknown position. Jc3s5h (talk) 15:58, 7 November 2023 (UTC)