[Merkaartor] Problems with data alignment when panning

[David Fawcett]

Chris,

The WMS URI is http://geoint.lmic.state.mn.us/cgi-bin/wms?

The layer is under >Statewide and is called 2008 Color...

The SRS is EPSG:26915 and the image format is jpeg.

Here is the custom SRS entry in Projections.xml:
  <Projection name="UTM 15N NAD83 (epsg:26915)" >+proj=utm +zone=15
+ellps=GRS80 +datum=NAD83 +units=m +no_defs </Projection>

I couldn't figure out how to view the bbox in Merkaartor, but here is
an OSM url that fits the area pretty closely:
http://www.openstreetmap.org/?lat=47.74746&lon=-90.33634&zoom=16&layers=B000FTF

It seems as though the shift occurs when moving multiple pans in one
direction.  I have been able to get it back in alignment by moving
around and returning to the scale at which the download was done.

Please let me know if there is anything else that I can do to track it down.

David.

On Wed, Dec 9, 2009 at 10:06 AM, Chris Browet <cbro at semperpax.com> wrote:
> Could I have:
>
> - The settings of the WMS you're using;
> - The BBOX of the area of the png
> - The projection you're using (if not default)
>
> Thanks
> - Chris -
>
> On Wed, Dec 9, 2009 at 15:24, David Fawcett <david.fawcett at gmail.com> wrote:
>>
>> I am using the new 1.4 binary recently created for Mac OSX.
>>
>> My basemap layer is a WMS in a local UTM Zone.  I line the OSM data up
>> with the image, but after I pan around using the arrow keys, the data
>> does not align with the image anymore.  Is this a known issue?
>>
>> The problem is additive, increasing with additional pans.  If I zoom
>> out a few levels and go back to the original start point, I can get
>> alignment again.
>>
>> I put an image demonstrating the issue at:
>> http://www.flatlandmaps.com/images/bad_align2.jpg
>>
>> This is a case where the alignment has shifted multiple times.  I
>> haven't tested it fully, but I would say that it almost always shifts
>> to the south.
>>
>> David.
>>
>> _______________________________________________
>> Merkaartor mailing list
>> Merkaartor at openstreetmap.org
>> http://lists.openstreetmap.org/listinfo/merkaartor
>
>
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