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I'm having an issue with several WMS feeds that i'm looking at, where their bounding box seems wrong. I think i would assume the issue is with the provider, but there are multiple enough that i think that maybe the problem is with how i'm interpreting the data?

For example, take http://inspirepub.waterinfo.be/arcgis/services/risicokaarten/MapServer/WMSServer?SERVICE=WMS&REQUEST=Getcapabilities

if you look at the top level layer, the bounding box is:

<BoundingBox CRS="EPSG:4326" minx="50.638080" miny="2.539990" maxx="51.505965" maxy="5.936689"/>

which looks like the following imageenter image description here

which is the small grey box off the east coast of africa. I have the same problem withe these other three sites, all independent of each other:

https://geoservices.informatievlaanderen.be/raadpleegdiensten/GRB/wms?SERVICE=WMS&REQUEST=Getcapabilities

https://mercator.vlaanderen.be/raadpleegdienstenmercatorpubliek/tn/tn:tn_refpt_awv/wms?SERVICE=WMS&REQUEST=Getcapabilities

http://geo.gent.be/geoserver/wms?SERVICE=WMS&REQUEST=Getcapabilities

These all have the '.be' domain so i assume they should be in, or at least near belgium. Am i reading the data wrong here? Or is there something else going on that i don't understand?

  • Possibly something to do with reversed coordinates order with EPSG:4326 in WMS 1.3.0 viswaug.wordpress.com/2009/03/15/… – user2856 Feb 4 at 5:19
  • GeoJSON uses CRS:84 with coordinates in lon/lat order. EPSG:4326 has coordinates in lat/lon order, so yes you are reading the data incorrectly – nmtoken Feb 4 at 13:43
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You are reading the longitude and latitude in wrong order from the EPSG:4326 BoundingBox. If you read the whole response from that server you should notice that WMS version 1.3.0 tries to give this information explicitly with the GeographicBoundingBox so that users would not need to know the official axis order of each CRS. WMS 1.3.0 also recommends to show the CRS:84 bounding box which is the same as EPSG:4326 but with longitude-latitude axis order.

<EX_GeographicBoundingBox>
<westBoundLongitude>2.539990</westBoundLongitude>
<eastBoundLongitude>5.936689</eastBoundLongitude>
<southBoundLatitude>50.638080</southBoundLatitude>
<northBoundLatitude>51.505965</northBoundLatitude>
</EX_GeographicBoundingBox>
<BoundingBox CRS="CRS:84" minx="2.539990" miny="50.638080" maxx="5.936689" maxy="51.505965"/>
<BoundingBox CRS="EPSG:4326" minx="50.638080" miny="2.539990" maxx="51.505965" maxy="5.936689"/>
<BoundingBox CRS="EPSG:3857" minx="282750.376029" miny="6557522.159667" maxx="660869.210327" maxy="6711285.878825"/>
<BoundingBox CRS="EPSG:102100" minx="282750.376029" miny="6557522.159667" maxx="660869.210327" maxy="6711285.878825"/>
<BoundingBox CRS="EPSG:31370" minx="20733.769332" miny="147431.828672" maxx="260998.994426" maxy="245548.161006"/>
  • ok, that was what was mixing me up i guess, i thought the order was only determined by the WMS version, i didn't realize it could be variable based on the bounding box CRS value as well. – Phil Feb 4 at 14:04

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