[mapserver-users] WMS help with dataline issues

[pcreso at pcreso.com]

A few possible approaches... for both vector & raster data



Try this at the clent side:



http://openlayers.org/dev/examples/wrapDateLine.html



I have also (in PostGIS) replicated vector data in the western hemisphere so the global dataset extends from -180 to 360.



Also, depending on whether or not you have polygons/linestrings crossing
 180, I've used the Postgis shift_longitude() function to resolve this 
serverside.



Also, take your +-180 raster map, with a tool like imagemagick, chop it 
in half at 180, & create an eastern hemisphere with an extent of 
0-180, and two western hemispheres, one with an extent from -180-0 &
 one from 180-360. In your map file set all three to status default so 
they are always on, or make them members of the same group so they can 
be de/selected as a single layer.



There are a few hacks around this, but not many definitive answers.

--- On Tue, 3/22/11, Tim Erwin <taerwin at gmail.com> wrote:

From: Tim Erwin <taerwin at gmail.com>
Subject: [mapserver-users] WMS help with dataline issues
To: mapserver-users at lists.osgeo.org
Date: Tuesday, March 22, 2011, 2:37 PM

I am using raster data from naturalearthdata which is in EPSG:4326 [-180 -90 180 90]. But when requesting data via openlayers with the map centred at 180E it only draws up to 180E. Below is one of the requests from openlayers: 


http://localhost/mapserv.cgi?map=naturalearth.map&LAYERS=NE1&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&FORMAT=image%2Fjpeg&SRS=EPSG%3A4326&BBOX=165,-30,215,20&WIDTH=256&HEIGHT=256


How do I get mapserver to render past 180E (or other options)? 

Regards,

Tim

######MAPFILE########

MAP
    NAME "NaturalEarth"
    IMAGETYPE      PNG24
    SIZE           800 600

    SHAPEPATH      "./data"
    EXTENT -180 -90 180 90
    DEBUG 3

    WEB
        METADATA
            "wms_title"                  "NaturalEarth WMS"
            "wms_srs"                   "EPSG:4326"

        END
    END

    PROJECTION
       "init=epsg:4326"
    END

    #
    # Start of layer definitions
    #
    LAYER
        NAME "NE1"
        DATA "NE1_HR_LC_SR_W_DR.tif"

        TYPE RASTER
        STATUS ON

        PROJECTION
           "init=epsg:4326"
        END

    END

END #mapfile


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