[josm-dev] projection Mercator, set EPSG 3785 instead of EPSG 3857

[Tobias Wendorff]

Am 08.03.2011 18:07, schrieb Sebastian Klein:
> In 3857 you start with WGS84 coordinates and blindly apply the spherical
> formula. This is exactly what we do.

I agree with the other points, but not with this one. When "drawing"
with JOSM's mercator projection, we're not creating WGS84 coordinates.
We're creating coordinates, which lay on the sphere.

That's okay for EPSG:3857, but what happens on imports?
When importing GPX coordinates or GPS data into JOSM, we're working
with *real* WGS84. So, we've got mixed those two up.

Actually, it's a question, how JOSM handles the data. From what
I've figured out, it just handles the WGS84 data as spherical
data. JOSM projects them using Pseudo-Mercator. That's what I
wanted to show with my calculations.