Working with WMS: Difference between revisions
Brian Wilson (talk | contribs) m New page: == Find out what a WMS service can do == Start with the basic URL http://wms.oregonexplorer.info/ImageX/ecw_wms.dll? Then add the capabilities request http://wms.oregonexplorer.info/Im... |
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== Resources == | |||
This GeoServer page has a good description of WMS services. https://docs.geoserver.org/stable/en/user/services/wms/reference.html | |||
The (somewhat dry technical) standard is at OGC is here: https://www.ogc.org/standards/wms | |||
and the reference/demo server is here: https://www.ogc.org/standards/wms/quickstart | |||
== Find out what a WMS service can do == | == Find out what a WMS service can do == | ||
Start with the basic URL | Start with the basic URL, this is the OGC reference server. This will just return a (relatively useless) informational message. | ||
http://metaspatial.net/cgi-bin/ogc-wms.xml | |||
Then add the GetCapabilities request (note these are not supposed to be case sensitive, so REQUEST=request) | |||
http://metaspatial.net/cgi-bin/ogc-wms.xml?request=GetCapabilities&service=wms | |||
This will return an extensive XML file with the capabilities of the server listed. | |||
== Find out about a layer == | |||
Plucking the name of a layer from a GetCapabilities request, I can ask for more information on that layer. | |||
If I omit the version I get an error. | |||
This does not return information on layer 1 alas. It just gives me the top level info again. Oh well I press on. Fix this later | |||
https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&LAYERS=1&REQUEST=DescribeLayer&VERSION=1.3.0 | |||
== Get information from a queryable layer == | |||
=== | https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetFeatureInfo&LAYERS=1&STYLES=&SRS=EPSG:4326&BBOX=-124.1,46.3,-123.35,-45.77&WIDTH=1&HEIGHT=1&QUERY_LAYERS=1&INFO_FORMAT=HTML&X=-123.817605&Y=46.181317 | ||
== Setting the SRS == | |||
I can add the SRS like this: | In my case, the default for this server is to return its images in "EPSG=4326" which is unprojected WGS84. | ||
If I want Oregon state system "EPSG=2992" I can add the SRS like this: | |||
https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&SRS=EPSG:2992 |
Latest revision as of 22:13, 28 February 2020
Resources
This GeoServer page has a good description of WMS services. https://docs.geoserver.org/stable/en/user/services/wms/reference.html
The (somewhat dry technical) standard is at OGC is here: https://www.ogc.org/standards/wms and the reference/demo server is here: https://www.ogc.org/standards/wms/quickstart
Find out what a WMS service can do
Start with the basic URL, this is the OGC reference server. This will just return a (relatively useless) informational message.
http://metaspatial.net/cgi-bin/ogc-wms.xml
Then add the GetCapabilities request (note these are not supposed to be case sensitive, so REQUEST=request)
http://metaspatial.net/cgi-bin/ogc-wms.xml?request=GetCapabilities&service=wms
This will return an extensive XML file with the capabilities of the server listed.
Find out about a layer
Plucking the name of a layer from a GetCapabilities request, I can ask for more information on that layer. If I omit the version I get an error.
This does not return information on layer 1 alas. It just gives me the top level info again. Oh well I press on. Fix this later
https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&LAYERS=1&REQUEST=DescribeLayer&VERSION=1.3.0
Get information from a queryable layer
https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetFeatureInfo&LAYERS=1&STYLES=&SRS=EPSG:4326&BBOX=-124.1,46.3,-123.35,-45.77&WIDTH=1&HEIGHT=1&QUERY_LAYERS=1&INFO_FORMAT=HTML&X=-123.817605&Y=46.181317
Setting the SRS
In my case, the default for this server is to return its images in "EPSG=4326" which is unprojected WGS84. If I want Oregon state system "EPSG=2992" I can add the SRS like this:
https://gis.blm.gov/arcgis/rest/services/vegetation/BLM_Nat_AIM_Terrestrial/MapServer/WMSServer?SERVICE=WMS&SRS=EPSG:2992