[mapserver-users] mapserver scalebar

[Lars Lingner]

Am 16.09.2011 13:05, schrieb Rahkonen Jukka:
> Hi,
> 
> A meter based scalebar cannot work very well with epsg:4326 because
> the more north you go the narrower is the 1 degree slice in east-west
> direction. Therefore you will have a different scale in the top of
> the map and in the bottom. Some estimate could be done according to
> the latitude in the middle of the image, in your case ~120 m.
> However, the scale is also different in the east-west and south-north
> directions. Use a coordinate system like UTM and the scalebar will be
> right. EPSG:3857 has the same trouble with scale changing according
> to latitude, though in a bit different way. Lappland is not as wide
> as in this map, not to mention the gigantic Svalbard
> http://osm.org/go/1mH7
> 

Thank you Jukka. With your explanation I can understand the problem.
Even better: with an UTM based projection the scalebar has the right
size and values.

Have a nice weekend.


Lars