[josm-dev] Problems creating TileSource for ArcGIS REST API

[Josh Doe]

Ian,
I've tried various combinations of spatial references and haven't
quite got it working. I use the tileYToLat/tileXToLon functions which
give me decimal degrees in WGS84 (EPSG:4326), so I can't use
bboxSR=102113 without converting those coordinates. With the Proj4J
plugin I used EPSG:3857 (equivalent to ESRI:102113 and ESRI:102100),
and that eliminates the gaps but now there are slight shifts between
each tile, so clearly something is still awry. I thought setting
imageSR=102113 would fix the slight shifts, but then I don't get any
image returned.

Tobias,
I've found it very confusing to understand what spherical mercator is
and the various codes involved, so much so that I created a wiki page
on EPSG:3857 [1].

All,
One thing that bothers me in JOSM is the Mercator projection claims to
be EPSG:3857, however it gives values in radians, not meters which
EPSG:3857 uses. I'm not even sure what EPSG/ESRI/etc identifier
corresponds to to this, but I think we should change it to avoid
confusion (took me a while to realize it was "wrong").

Shouldn't we change this code to avoid confusion and to "be right"?
I'm guessing people use the projection, so we shouldn't "fix" it but
rather give it the correct code if we can find it or invent one,
probably via SpatialReference.org.

Thanks,
-Josh

[1]: http://wiki.openstreetmap.org/wiki/EPSG:3857

On Thu, Feb 17, 2011 at 12:35 PM, Tobias Wendorff
<tobias.wendorff at tu-dortmund.de> wrote:
> Am 17.02.2011 17:15, schrieb Ian Dees:
>>
>> Don't reproject your coordinates to Virginia, just tell ArcGIS that your
>> request bounding box is in Spherical Mercator projection by passing in a
>> projection id of 102113.
>
> Interesting information on this topic:
> http://forums.esri.com/Thread.asp?c=93&f=984&t=288073&g=1
>