Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Good news on this. Further experimentation revealed that it is possible to get reasonably good agreement between scales in OpenLayers and GeoServer using the following approach: - use OpenLayers NON-geodesic (nominal) scale calculation - set OpenLayers DOTS_PER_INCH to match the GeoServer value

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Thanks for the advice - and for the warning. Sigh On Tue, Feb 16, 2016 at 9:35 AM, Andrea Aime wrote: > On Tue, Feb 16, 2016 at 6:10 PM, Martin Davis wrote: > >> Thanks, Andrea. I suspected this might be the cause of the issue. >> >> Is

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

On Tue, Feb 16, 2016 at 6:10 PM, Martin Davis wrote: > Thanks, Andrea. I suspected this might be the cause of the issue. > > Is there a way to view the scale computed for a map request? That might > let us correlate the client (geodetic) scale to "OGC scale", so we can >

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Thanks, Andrea. I suspected this might be the cause of the issue. Is there a way to view the scale computed for a map request? That might let us correlate the client (geodetic) scale to "OGC scale", so we can translate between the two. On Tue, Feb 16, 2016 at 12:40 AM, Andrea Aime

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

On Tue, Feb 16, 2016 at 12:05 AM, Martin Davis wrote: > Are you suggesting that GeoServer computes the scale at a single known > point for all map request extents, no matter where on the globe they are > located?Does the OGC standard specify this? > The OGC standard

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Are you suggesting that GeoServer computes the scale at a single known point for all map request extents, no matter where on the globe they are located?Does the OGC standard specify this? If so, I guess that might explain the discrepancy between SLD scale and true image scale, at our

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Yes, we realize that's an issue. In our case we're only concerned with a relatively small area (the province of BC), so the variation in true scale across the area is not that large (around 20%). We realize that we won't get 100% correlation, but we'd like to at least get it looking right better

Re: [Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

Hi, I am not sure if I understood the problem but I wonder how the true scale suits together with Web Mercator. I guess that you do not expect that the tiles of the same zoom level would use different styles at equator than in Canada or Finland even the true scale differs a lot. -Jukka

[Geoserver-users] Scale discrepancy between Web Mercator and BC-Albers

We are displaying map images in Web Mercator, from a GeoServer with native CRS as BC-Albers (EPGS:3005). We are using an OpenLayers client to display the map images. We have confirmed that the geodetic scale displayed by OpenLayers is approximately the true scale of the map images (modulo the