WMS GetCapabilities

< Interoperability of Air Quality Data Systems

WMS Document

• WMS Documentation

WMS Service Checkers

• FGDC WMS Status Checker - Checks the WMS GetCapabilities and GetMap for function in one step (returns XML)
  • You may be able to call the FGDC WMS Service Checker as a service now. You can replace the getCapabilities link with any GetCapabilities and it returns html or xml - Here is the URL:
    • http://registry.fgdc.gov/statuschecker/services/rest/index.php?url=http://webapps.datafed.net/AIRNOW.ogc?SERVICE=wms&REQUEST=GetCapabilities&VERSION=1.1.1&REQUEST=GetCapabilities&type=wms&formattype=xml
    • http://registry.fgdc.gov/statuschecker/services/rest/index.php?url=http://webapps.datafed.net/AIRNOW.ogc?SERVICE=wms&REQUEST=GetCapabilities&VERSION=1.1.1&REQUEST=GetCapabilities&type=wms&formattype=html

• ESA WMS Checker - Will test GetCapabilities (returns original GetCapabilities or error message) and in separate step GetMap (returns map or error)

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

• Datafed Airnow
• CIESIN
• NASA NEO WMS

WMS Viewers

• ESIP Stresa WMS Demo
• ESRI Previewer
• DataFed Browser

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">
 <Name>Ozone_adv</Name> 
 <Title>OMI_AI_G:Column Amount Ozone</Title> 
<KeywordList>
 <Keyword>Domain:Aerosol</Keyword> 
 <Keyword>Dataset:OMI_AI_G</Keyword> 
 <Keyword>Platform:Satellite</Keyword> 
 <Keyword>DataType:GRID</Keyword> 
 </KeywordList>
 <SRS>EPSG:4326</SRS> 
 <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">
 <Format>text/xml</Format> 
 <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" /> 
 </MetadataURL>
<DataURL>
 <Format>text/html</Format> 
 <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" /> 
 </DataURL>
<Style>
 <Name>data</Name> 
 <Title>Data</Title> 
 </Style>
<Style>
 <Name>default</Name> 
 <Title>Default</Title> 
 </Style>
 </Layer>

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