[OpenLayers-Users] reprojection issue
michael.ocleirigh at rivulet.ca
Wed Jun 10 13:04:58 EDT 2009
I had a similar type of problem with WMS in OpenLayers when showing a
layer served through Geoserver. i.e. The features were offset
incorrectly when reprojected onto a Google Maps base layer.
My source layer is in the NAD 83 UTM Zone 17N EPSG:26917 projection. But
in order to get it to reproject to the Google EPSG:900913 properly I
needed to first convert the layer into standard NAD 83 degree unit
I see that EPSG:32632 is similar to 26917 in that its unit is meter.
Can you try converting the layer into the appropriate WGS84 degree
projection first and see if that helps?
> Hi Jan,
> Unless I am very much mistaken, http://www.dmap.co.uk/utmworld.htm
> shows Tunisia to be squarely in UTM 32 N. I have ArcGIS and my
> landsatt data for the region all fall into UTM 32 N, which is why I
> believe this is in fact the case.
> UTM Zone 32 N is also EPSG:32632
> http://spatialreference.org/ref/epsg/32632/ so I still don't know what
> going on.
> UTM coordinates are arbitrary cartesian points, which basically could
> end up anywhere which is why the UTM zone is needed for the origin.
> The only thing I can think is that yes, there is some issue with the
> projection, but I don't know what.
> On Wed, Jun 10, 2009 at 12:38 PM, Jan Martin
> <janmartin3 at googlemail.com <mailto:janmartin3 at googlemail.com>> wrote:
> Hi Nicholas,
> your assumption regarding your source UTM Zone beeing UTM 32N is
> Your coordinates are from Tunisia. And Tunisia is UTM 32S, not UTM
> But as you can see here EPSG:32632 is the right result of a
> conversion from UTM Zone 32S to EPSG:
> Question remains why your coordinates from Tunisia are displayed
> in Algeria.
> I wonder if it is OK to just use EPSG:32632 as a projection for
> your data, or if one would have to do math on the coordinates to.
> After all your coordinates have been recorded in *WGS84, UTM 32S.*
> On Wed, Jun 10, 2009 at 6:08 PM, Nicholas Efremov-Kendall
> <n.e.kendall at gmail.com <mailto:n.e.kendall at gmail.com>> wrote:
> Hello all,
> I believe this is more of a gis question, than for OpenLayers,
> but the problem manifests itself in openlayers and I'm having
> some trouble diagnosing it. Jan provided me with some very
> helpful assistance, which led me to the conclusion that my
> projection was wrong. I'm trying to display gps point
> originally recorded in UTM 32N. I had mistakenly believed this
> was EPSG 22332, but 36232 is actually what I was going for. My
> problem is this: I have the points overlaid on a wms server
> (thanks to Jan) but they're in the wrong spot. However, when I
> change the EPSG code, the points don't move. Does anyone have
> a suggestion for why they don't move? and or for how to crack
> this nut.
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