[OSM-talk] quality of drawn way

[Mike Collinson]

At 11:36 AM 11/05/2007, Nick Burch wrote:
>On Fri, 11 May 2007, Mike Collinson wrote:
>>Arriving recently in the UK and applying the same principle to NPE, I find it is only possible to align very, very locally. I'm not familiar with the stretch properties of map paper over time but the size and local randomness of the misalignment makes me suspect that it is due to inaccuracy in the original survey and not paper or scanning artifacts.
>
>Were you using the wms server, or the gpx tracer? I'm pretty sure that the wms server isn't correctly projecting the maps, and so is introducing extra distortions (eg there are areas where the gpx tracer gives no calibration errors, but the wms one has bad ones still)
>
>So far, I haven't been able to get anyone to admit to running the NPEmap wms server on dev, so no-one has fixed it :(
>
>Nick
>(Who just feeds the wms server the npemap tiles, and has no idea what it does after that)

I use the out-of-the-box JOSM settings, I'm not sure what alternatives you are referring to. GPS traces from my own GPX files (also uploaded and marked public), OSM data directly downloaded, Landsat http://onearth.jpl.nasa.gov/wms.cgi?request=GetMap&layers=global_mosaic&styles=&srs=EPSG:4326&format=image/jpeg and NPE data from http://nick.dev.openstreetmap.org/openpaths/freemap.php?layers=npe.  JOSM is set to EPSG:4236 projection.

Mike