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

Josh Doe josh at joshdoe.com
Thu Feb 17 20:39:19 GMT 2011


Ian,
Thanks for the fast response. I believe I tried that, but to make sure
I tried it again, and it doesn't work. For some reason with
imageSR=102113 I get a blank (white) image. For fun I also tried the
equivalent imageSR=102100 with no luck. You can see the request is
blank here [1], while clearing imageSR results in an image, though not
of the right projection. To be honest I don't really understand how
the imageSR relates to the bbox and bboxSR.

Is it possible this instance of the ArcGIS server can't reproject the
image to this SR? I'm outside of my knowledge area if you haven't
guessed already. :)

Thanks,
Josh

[1]: http://gismaps.virginia.gov/arcgis2/rest/services/VBMP2006_2007/MapServer/export?bbox=-77.310791,38.794768,-77.308044,38.792627&size=256,256&bboxSR=4326&imageSR=102113&format=jpg&f=html
[2]: http://gismaps.virginia.gov/arcgis2/rest/services/VBMP2006_2007/MapServer/export?bbox=-77.310791%2C38.794768%2C-77.308044%2C38.792627&bboxSR=4326&layers=&layerdefs=&size=256%2C256&imageSR=&format=jpg&transparent=false&dpi=&f=html

On Thu, Feb 17, 2011 at 3:16 PM, Ian Dees <ian.dees at gmail.com> wrote:
> Use bboxSR=4326 (to specify the bounding box in 4326) and imageSR=102113 to
> get the image back projected to Spherical Mercator.
> The imageSR parameter may be called something else, but I do know that an
> output projection option exists somewhere.
>
> On Thu, Feb 17, 2011 at 2:09 PM, Josh Doe <josh at joshdoe.com> wrote:
>>
>> 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
>> >
>
>



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