[PROJ] "Local" projection method?

[Luí­s Moreira de Sousa]

Hi Nyall,

while I am not an oracle, I never before seen this projection called that way. It is one of the oldest projections used in cartography, was called different names in history, but "Local" is the first I see. Currently, the extensive CRS database from ESRI does not include a single system composed by a "Local" projection, although it contains many with "Orthographic".

My best guess is ESRI having used the term "Local" referring to a particular parametrisation of the Orthographic. It might be helpful to contact the company about this.

Regards.

--
Luís

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, September 24, 2020 1:54 AM, Nyall Dawson <nyall.dawson at gmail.com> wrote:

> On Thu, 24 Sep 2020 at 09:33, Nyall Dawson nyall.dawson at gmail.com wrote:
>
> >
>
> > I've been trying to research exactly what this "Local" projection means.
> > There's some documentation for it here:
> > https://pro.arcgis.com/en/pro-app/help/mapping/properties/local.htm
>
> There's also this comment:
> https://community.esri.com/thread/245500-the-local-projection-and-its-matehamtics#comment-898492
>
> "EPSG is planning to add the Local projection to its registry. I've
> been slowly, very slowly writing up the mathematics so that it can be
> published in the 7-2 Guidance Note. I'm hoping to finish it up over
> the holidays."
>
> But that's the last mention I can find relating to this promised write up...
>
> Nyall
>
> PROJ mailing list
> PROJ at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/proj