[mapserver-users] mapserver scalebar
gislars+list at googlemail.com
Fri Sep 16 06:41:38 EDT 2011
I have an issue with the mapserver scalebar. Hopefully it is just my
understanding thats wrong.
My data is epsg:4326 which is also used for displaying the map requested
When I embed a scalebar, the length of it isn't correct. It show an
value about as twice (200+ meter) the right value (~120 m).
The region I'm displaying is in northern europe about 55.8 latitude.
My mapfile looks like this:
IMAGECOLOR 255 255 255
COLOR 0 0 0
SIZE 100 3
COLOR 0 0 0
I'm using MapServer 5.6, data comes from shapefiles and Postgis-DB.
It is quite important to have an scalebar rendered in the image so the
user can estimate the objects length.
I also tested the scalebar from OpenLayers and for epsg:4326 its also
wrong. When I use epsg:3857 with the geodesic=true option the scalebar
in OpenLayers looks correct. Whereas MapServer is still wrong.
Is MapServer able to calculate an correct scalebar for 4326?
Should I use an other projection?
In which cases does MapServer create a reliable scalebar?
Thank you in advance for any hints.
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