National Oceanic and
Atmospheric Administration
United States Department of Commerce

Basic WMS Requests

Last modified: Tue, 03/14/2017 - 00:19
Through a web browser, you could make GetMap and GetCapabilities requests.

The WMS service of LAS (Armstrong 1.1 and up) was implemented based on OGC WMS standard version 1.1.1.

WMS base URL

If the URL of a LAS server is:

http://porter.pmel.noaa.gov:8922/wms/servlets/dataset

The WMS of this LAS server has a base URL prefix:

 http://porter.pmel.noaa.gov:8922/wms/wms_servlet?

You could use this base URL in a WMS client, or make WMS requests through a web browser.

GetCapabilities

A GetCapabilities request provides information about a WMS service, such as image formats it can serve, list of one or more map layers available in the service etc. This example shows the minimum number of parameters needed to make a successful GetCapabilities request.

http://porter.pmel.noaa.gov:8922/wms/wms_servlet?REQUEST=GetCapabilities&VERSION=1.1.1&SERVICE=WMS

where

GetMap

A GetMap request retrieves a map from the WMS server. It allows the client to specify layers, the spatial reference system, the geograpic area, time values, and other parameters. The following example shows how to make a GetMap request.

http://porter.pmel.noaa.gov:8922/wms/wms_servlet?VERSION=1.1.1&REQUEST=GetMap&LAYERS=coads_climatology_cdf:airt&STYLES=ferret_default&WIDTH=640&HEIGHT=320&FORMAT=image/png&SRS=EPSG:4326&BBOX=-180.0,-90.0,180.0,90.0&EXCEPTION=application/vnd.ogc.se_xml&DIM_COADS_CLIMATOLOGY_CDF_TIME=15-Jan

where

  • http://porter.pmel.noaa.gov:8922/wms/ is the LAS base URL
  • http://porter.pmel.noaa.gov:8922/wms/wms_servlet? is the WMS base URL
  • VERSION=1.1.1 is the WMS request version
  • REQUEST=GetMap is the request name
  • LAYERS=coads_climatology_cdf:airt is the layer request in the servive, i.e., variable 'airt' in dataset 'coads_climatology_cdf'
  • STYLES=ferret_default is the style reference, another option is ferret_contour
  • WIDTH=640&HEIGHT=320 are the width and height of the requested image in pixels
  • FORMAT=image/png is the requested image format
  • SRS=EPSG:4326 is the spatial reference value
  • BBOX=-180.0,-90.0,180.0,90.0 is the bounding box in SRS coordinates of the map
  • EXCEPTION=application/vnd.ogc.se_xml isthe format in which exceptions are to be reported by the WMS
  • DIM_COADS_CLIMATOLOGY_CDF_TIME=15-Jan is the time dimensional value