[Qgis-user] Best practice when using UK national grid and GPS

[Saber Razmjooei]

Hi Jim,

Here is a full article on how projections (specifically the British
National Grid) work in QGIS and what you can do to improve your data
collection when using on-the-fly transformation:
https://merginmaps.com/docs/gis/projections/#projections

Kind regards
Saber


On Fri, 1 May 2026 at 19:36, Jim Jackson via QGIS-User <
qgis-user at lists.osgeo.org> wrote:

>
>
> QGIS version  3.40.6-Bratislava
> QGIS code branch Release 3.40
> OS Linux Devuan GNU/Linux 6 (excalibur) (basically Debian Trixie)
>
> Hi All,
>
> As a member of a community Archaeology Group, I'm using QGIS for recording
> archaeological features in the UK. I'm using Google Satellite,
> OpenStreetMap and National Library of Scotland historic basemaps, which
> (as
> I understand it) use EPSG:3857.
>
> I have an RTK GPS receiver for collecting data points which are in
> EPSG:4326.
> I
> also get UK National Grid data points from a colleague who has access to a
> total station.
>
> As I think I understand it, I need to set the project CRS to UK national
> grid EPSG:27700 to get sensible distance measurements However I then get
> occasional warnings "Used a ballpark transform from EPSG:27700 to
> EPSG:3857" indicated less than accurate transformations, and then I get
> lost!!!!
>
> Can anyone point me to a tutorial on how to set up QGIS in the UK to get
> accurate transformations in these circumstances (which can't be that
> unusual).
>
> Any advice and/or pointers where I've gone wrong gratefully received.
>
> Jim Jackson
>
>
> _______________________________________________
> QGIS-User mailing list
> QGIS-User at lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>


-- 

Saber Razmjooei

Co-Founder

lutraconsulting.co.uk

 [image: https://www.linkedin.com/in/saber-razmjooei/]
<https://www.linkedin.com/in/saber-razmjooei/>
<https://www.youtube.com/@LutraConsulting>
<https://github.com/lutraconsulting>

<https://www.lutraconsulting.co.uk/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20260504/0ef78224/attachment-0001.htm>