WMS GetCapabilities

From Earth Science Information Partners (ESIP)

< Interoperability of Air Quality Data Systems

WMS Document

WMS Service Checkers

  • ESA WMS Checker - Will test GetCapabilities (returns original GetCapabilities or error message) and in separate step GetMap (returns map or error)
  • mapmatters.org - Catalogues WMS Services and offers optional monitoring of performance and availability. For all services and layers the site presents meta data from the GetCapabilities, map previews and optional statistics.

WMS Time

Each layer should have time in begin_time/end_time/periodicity (pg 68 of WMS 1.1.1 Documentation)

  • Example: Daily data taken at noon since April 15 1995 (periodic interval): 1995-04-22T12:00Z/2000-06-21T12:00Z/P1D

WMS Style

Image size should only include portion of image with data. Decoration should be handled separately

  • Common error in WMS is to include decorations (margins, legends, ...) in the bbox size. This causes the data to not be properly geocoded.

Example WMS Layers

WMS Viewers

WMS GetCapabilities Layer Description

We used NASA NEO WMS as an example of a well-behaving WMS and have updated our WMS GetCapabilities to model it. We use WMS GetCapabilities plus additional metadata to create ISO 19115 Air Quality Community Catalog metadata records. Below is a valid WMS layer and it includes the Keyword list for 4 facets that we currently search by with a "controlled vocabulary": Domain, Platfrom, Dataset, DataType.

Sample WMS Layer:

<Layer queryable="0">
 <Title>OMI_AI_G:Column Amount Ozone</Title> 
 <LatLonBoundingBox minx="-180" miny="-90" maxx="180" maxy="90" /> 
 <Dimension name="time" units="ISO8601" /> 
 <Extent name="time" default="2007-05-12T00:00:00Z">2004-08-17T00:00:00Z/2009-05-28T00:00:00Z/P1D</Extent> 
<MetadataURL type="TC211">
 <OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://capita.wustl.edu/DataspaceMetadata_ISO/DataFed.OMI_AI_G.Ozone_adv.xml" xlink:type="simple" /> 
 <OnlineResource xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://webapps.datafed.net/browser.aspx?dataset_abbr=OMI_AI_G&param_abbr=Ozone_adv" xlink:type="simple" /> 

Look at Machine tags - may be able to use. Current facets (Domain, Platfrom, Dataset, DataType, ...)and allowed values are:

  • Domain: Aerosol, Demographic, Emission, Fire, GIS, Meteor
  • Platform: Satellite, Model, Network
  • Format: Grid, Point, SeqImage, Arrow, Table Traj, Vector
  • Parameter: Develop ontology
  • Vertical
  • Temporal: Monthly, Daily
  • Dif to ISO
  • Dif to GetCapabilities

ISO Record from OGC GetCapabilities:
ISO 19115 Record Generated from GetCapabilities Layer above

Catalog search of ISO Records:
Faceted search in AQ catalog

Below is a table with the fields for GetCapabilities mapped to ISO 19115 Doc (to edit):

Here is the sample ISO template with GetCapabilities: http://capita.wustl.edu/DataspaceMetadata_trial/OGC_ISO.Template.xml