[OpenLayers-Users] Coordinates shifted after upgrade from 2.10 to 2.11 / 2.12

[Joel Leininger]

We use 2.11 and also track Maryland State Plane values in our site, and
everything works well. However, our Maryland NAD83(m) is EPSG:2804, and
NAD83(f) is EPSG:2893. Could that be the source of your problem? Those
coords put me at the insn of Peachtree and Comus Rds in Montgomery
County, and they look fine.

Here's our site which offers real-time coord updates in a number of
systems as one pans around:

www.martenet.com/archives

You might want to compare what we have with yours.

-J.

On Tue, 2013-02-26 at 12:03 -0500, Jay Parsons wrote:

> Hello,
> 
> I am new to this list.  We have been using OpenLayers for several years, 
> but recently discovered an issue with the coordinates being shifted by 
> around 500 ft (150 m) after upgrading from 2.10 to 2.11, and the problem 
> still seems to exist in 2.12.
> 
> We are using a subclassed XYZ layer (subclassed to allow the origin to 
> be outside of the extents of the tiles, which our tile set requires) to 
> hit ArcGIS but otherwise it's straightforward - the display projection 
> is EPSG:4326 (plain lat/long) and the base layer projection is 
> EPSG:26985 (Maryland State Plane, which is a Lambert projection that 
> requires a custom definition for proj4js).
> 
> Positioning the mouse cursor over a particular intersection of roads on 
> the map using first OpenLayers 2.10 and then again using 2.11 reveals:
> 
> 39.24226, -77.32623  (OpenLayers 2.10)
> 39.24332, -77.32737  (OpenLayers 2.11)
> 
> Plugging the first numbers into Google Earth, they are correctly aligned 
> with the roads.  The second numbers are shifted and incorrect. 
> (Interestingly I usually see it shifted to the southeast, although in 
> this case it seems to be shifted to the northwest by the same distance). 
>   The offset is glaring at 1:16K, still quite visible at 1:32K, and 
> minor but visible at the 1:64K scale.
> 
> All of our vector objects are offset by a similar amount, but the mouse 
> position control vs. the base layer also illustrates it without 
> introducing vector layers as a potential suspect.
> 
> I could be wrong but I doubt that the problem is with the app-level code 
> because the difference is apparent by simply switching the OpenLayers 
> library.
> 
> I'm not sure if this is the same issue as Ticket #3640 
> (http://trac.osgeo.org/openlayers/ticket/3640) as there is not a lot of 
> information given in that ticket, but the order of magnitude of the 
> error looks about the same.
> 
> Any info or insight would be appreciated.  Thanks.
> 
> Jay
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