• 1. OGC, WMS and WFS
  • 1.1. Terms
  • 1.2. OGC
  • 1.3. WMS
    • 1.3.1. What WMS is
    • 1.3.2. GetMap
    • 1.3.3. GetCapabilities
    • 1.3.4. GetFeatureInfo
    • 1.3.5. Free Mapservers
    • 1.3.6. SLD
    • 1.3.7. Unit-Summary
  • 1.4. WFS
  • 1.5. Summary
  • 1.6. Self Assessment
  • 1.7. Glossary
  • 1.8. Bibliography
  • 1.9. Metadata

1.3.7. Unit-Summary

Web Map Service is a standard that provides a standard interface for querying and accessing map layers from a mapping server.
WMS defines the following operations:

1. How to get and provide information about what types of maps a server can deliver (GetCapabilities)
2. How to request and provide a map as a picture or set of features (GetMap)
3. How to get and provide information about the content of a map such as the value of a feature at a location (GetFeatureInfo)

The result of a GetMap request is a raster image as it is shown in the image below:

Result of a GetMap request (UMN MapServer)

The result of a GetCapabilities request is a GML file that contains all map service metadata. The following image shows an extract of a GetCapabilities GML file:

Result of a GetCapabilities request (UMN MapServer)

The result of a GetFeatureInfo request is an XML file as well.

Keep in mind that a Web Map Service is usually not invoked directly. More often, it is invoked by a client application that provides the user with interactive controls. Nevertheless, you are able to request a map with a browser as we did in this unit.

Update: 26.1.2012 (eLML) - Contact - Print (PDF) - © CartouCHe 2004-2007 (Creative Commons) - layout based on YAML