[OSM-dev] Good explanation of latitude-to-pixel conversion?
David MENTRE
dmentre at linux-france.org
Sun May 25 14:59:30 BST 2008
Hello,
"Robert (Jamie) Munro" <rjmunro at arjam.net> writes:
> I don't understand. Why was it necessary?
According to the original poster, it improves the mapping by some 50
meters for some points, compared to projections made by a dedicated
software (proj4).
But I suppose all of this is quite subjective to the kind of projection
you are using and your purpose. And I'm certainly not a cartographer. :-)
> AFAICS, taking into account the variation of radius is *not* necessary,
> but can be done if you want to make the maths much harder for yourself.
The maths are not so difficult for Mercator projection but I agree are
more involved for other calculations. I have personally considered the
Earth a sphere when computing the distance between two points.
Sincerely yours,
david
--
GPG/PGP key: A3AD7A2A David MENTRE <dmentre at linux-france.org>
5996 CC46 4612 9CA4 3562 D7AC 6C67 9E96 A3AD 7A2A
More information about the dev
mailing list