Hi Chris, ah, thanks for the clarification. Yes, I've seen the trigpointing.uk site. There was also a thread relating to it back in 2019, if you've not seen it: https://lists.openstreetmap.org/pipermail/talk-gb/2019-July/023180.html
The OS trig data says (iirc) that it should still be accurate to 0.1m (I'll note, both the OS pages and the trigpointing.uk links are referenced from my github repo README file...) At present I have no intention to add any trigpointing.uk site info to any OSM nodes. I did see there are 335 existing `tpuk_ref` tags on man_made=survey_point nodes in OSM (as part of my existing tag analysis) which I think add the trigpointing.uk specific unique identifiers. On Tue, 9 Jun 2026 at 15:48, Chris Andrew <[email protected]> wrote: > Hi, Graham. > > My work is around > https://www.google.com/url?q=http://trigpointing.uk&source=gmail&ust=1781102438041000&sa=E > data (which I understand re-packages the OS archive), not the OS data > directly; so, a different source to yours, though very much the same > subject area. > > Owen's pointer to the OS trig archive under OGL is very useful — thank > you, Owen. I'll look at whether the coordinates there are precise enough > for app use, given the note about them predating the ETRS89/OSTN15 > transformation. > > On Tue, Jun 09, 2026 02:50 PM, Owen Boswarva <[email protected]> > wrote: > >> >> There's a current page on the Ordnance Survey website with a download of >> the legacy Trig Archive. It says the data is re-usable as open data under >> the Open Government Licence: >> >> Click on 'Read more': >> https://www.ordnancesurvey.co.uk/geodesy-positioning/legacy-data/trig-search >> >> -- Owen Boswarva >> >> >> On Tue, 9 Jun 2026 at 14:41, Graham Whaley <[email protected]> >> wrote: >> >> Hi Chris, >>> thanks for the reply. Is your work also around OS trigpoint data, or >>> some other dataset? >>> Licensing indeed - back in 2016 @gregrs approached the OS (it's listed >>> on the wiki page for trigpoints), and their response at that time was >>> positive: >>> >>> https://wiki.openstreetmap.org/wiki/User:Gregrs/Ordnance_Survey_triangulation_stations/Licence_emails >>> >>> I'm starting with the presumption that that still holds - but we should >>> indeed verify that before an import, no doubt in the import proposal page >>> phase. >>> >>> Graham >>> >>> On Tue, 9 Jun 2026 at 13:19, Chris Andrew <[email protected]> wrote: >>> >>>> Hi, Graham. >>>> >>>> Just for wider knowledge, I'm doing some work at the moment, along >>>> similar lines, but in support of an app, not a bulk import. >>>> >>>> Stating the obvious, before any bulk imports are considered, the source >>>> data licensing would need to be checked. >>>> >>>> I suspect people have been round this bouy a few times, so I'll step >>>> back, now. >>>> >>>> Chris >>>> chris_debian >>>> >>>> On Tue, 9 Jun 2026, 12:01 , <[email protected]> wrote: >>>> >>>>> Send Talk-GB mailing list submissions to >>>>> [email protected] >>>>> >>>>> To subscribe or unsubscribe via the World Wide Web, visit >>>>> https://lists.openstreetmap.org/listinfo/talk-gb >>>>> or, via email, send a message with subject or body 'help' to >>>>> [email protected] >>>>> >>>>> You can reach the person managing the list at >>>>> [email protected] >>>>> >>>>> When replying, please edit your Subject line so it is more specific >>>>> than "Re: Contents of Talk-GB digest..." >>>>> Today's Topics: >>>>> >>>>> 1. Revisiting OS trigpoints - viability of importing? () >>>>> >>>>> >>>>> >>>>> ---------- Forwarded message ---------- >>>>> From: Graham Whaley <[email protected]> >>>>> To: [email protected] >>>>> Cc: >>>>> Bcc: >>>>> Date: Tue, 9 Jun 2026 11:55:01 +0100 >>>>> Subject: [Talk-GB] Revisiting OS trigpoints - viability of importing? >>>>> Hello, >>>>> first time poster here. I've done a very few small submissions to OSM >>>>> in the past (user gwhaley), and just restarted updating small items around >>>>> my location (having spotted some new bins and benches etc. appearing). >>>>> >>>>> During that work I realised the trigpoints near me are not in OSM, >>>>> which led me down the path to this very useful wiki page from @gregrs >>>>> around 2016: >>>>> >>>>> https://wiki.openstreetmap.org/wiki/Ordnance_Survey_triangulation_stations >>>>> and a small related discussion on the list around 2019: >>>>> https://lists.openstreetmap.org/pipermail/talk-gb/2019-July/023176.html >>>>> >>>>> This inspired me to grab the current datasets and do some crunching. >>>>> I've posted my code and findings on github at: >>>>> https://github.com/grahamwhaley/OSM_UK_trigpoints >>>>> >>>>> I'd like to discuss if the community think it is viable to import a >>>>> bunch of OS trigpoint data? I think it is. I don't think we could automate >>>>> every trigpoint found in the OS data (see below and/or the github page for >>>>> details), but I think there is scope to import the vast majority of OS >>>>> trigpoints as nodes. Of course any import would follow the path of >>>>> following the import guidelines, writing an import plan and >>>>> approaching/announcing to the wider community before any automation >>>>> occurred. I'd also fully expect to do some dry runs and some smaller >>>>> region >>>>> imports before doing the bulk of the data. I'd also gladly welcome any >>>>> help, reviews etc. >>>>> >>>>> I'll drop a few statistics here... >>>>> >>>>> - The OS trigpoint database has 6081 'live' pillars >>>>> - The OSM database has 2804 items purporting to be trigpoints - 2560 >>>>> after some filtering >>>>> - The OS benchmark data (which gives us FlushBracket numbers) has >>>>> 3703 useable entries >>>>> >>>>> After some data crunching and filtering (see the github page - but I >>>>> fully expect to adapt and refine the current code), we end up with the >>>>> 6081 >>>>> OS nodes being classified into the following groups: >>>>> >>>>> - 60 OS entries that seem to align with existing OSM entries so likely >>>>> need no or little change >>>>> - 4440 potential 'new' OSM trigpoint entries - entries from the OS >>>>> data that do not seem to align with any existing OSM nodes >>>>> - 246 'editable' entries, where an OS entry nearly aligns with an OSM >>>>> entry, but we could 'coerce' the OSM entry to match the OS entry >>>>> - 1335 entries that could do with human review - the OS and OSM >>>>> entries are both similar and different (for example, might have matching >>>>> names but different FB numbers), and we could try and figure out why and >>>>> what to do in each instance. >>>>> >>>>> I have some ideas about how to proceed, but obviously would like >>>>> community input. My overview thoughts are: >>>>> >>>>> - Adding the 4440 'new' OS trigpoints feels like the least risk, as >>>>> it would not be trying to duplicate or modify any existing OSM nodes >>>>> - The 'editable' nodes might be moderately easy to apply after a >>>>> fairly thorough human review of the changes. >>>>> - The 1335 entries that could do with human review - maybe we can get >>>>> them on a >>>>> site like/similar to Survey Me or FHODOT to make them accessible for >>>>> ongoing community review. >>>>> >>>>> Many thanks, >>>>> Graham >>>>> >>>>> _______________________________________________ >>>>> Talk-GB mailing list >>>>> [email protected] >>>>> https://lists.openstreetmap.org/listinfo/talk-gb >>>>> >>>> _______________________________________________ >>>> Talk-GB mailing list >>>> [email protected] >>>> https://lists.openstreetmap.org/listinfo/talk-gb >>>> >>> _______________________________________________ >>> Talk-GB mailing list >>> [email protected] >>> https://lists.openstreetmap.org/listinfo/talk-gb >>> >> _______________________________________________ > Talk-GB mailing list > [email protected] > https://lists.openstreetmap.org/listinfo/talk-gb >
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