[OSM-talk] db and user statistics update

80n 80n80n at gmail.com
Fri Jan 19 10:57:27 GMT 2007


On 1/19/07, Johnny Doe <uucp1 at yahoo.com> wrote:
>
>
> --- "Robert (Jamie) Munro" <rjmunro at arjam.net> wrote:
> >
> > I know the author of the WMS-C
> > layer will probably
> > say Christopher Schmidt will say "But my projection
> > is right and yours
> > is wrong", but in fact they are both wrong.
>
> I doubt that your (and probably everybody else')
> GPS receiver uses a spheric Earth model
> to calculate the latitude and longitude from
> geocentric coordinates.
> WMS-C Mercator definition based on WGS84 ellipsoid
> is consistent with the measured lat/long data.


Can anyone explain why a simple spheric model is not sufficient?  Does it
result in cracks somewhere on the planet?  Are lat and lon coordinates
incorrect for someone's street somewhere?  Is the distance between two
points distorted in some way?

There have been several discussions on this subject but I've not seen any
explanation of why either one works better than than the other.

80n


____________________________________________________________________________________
> Be a PS3 game guru.
> Get your game face on with the latest PS3 news and previews at Yahoo!
> Games.
> http://videogames.yahoo.com/platform?platform=120121
>
> _______________________________________________
> talk mailing list
> talk at openstreetmap.org
> http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk/attachments/20070119/1cee53f5/attachment.html>


More information about the talk mailing list