Web Map Service
A Web Map Service (WMS ) is an interface to retrieve excerpts of maps on the World Wide Web. The WMS is a special case of web services.
The WMS Implementation Specifications
The specification of the Web Map Service was written by the Open Geospatial Consortium ( OGC). It describes the parameters that need to be named in a request or can. Next, it specifies how the WMS server generate the cut and possibly the substantive preparation of the map from such a request.
According to the specifications of the OGC WMS server can visualize the requested map from raster or vector data. In terms of a distributed geographic information system (GIS ) is a WMS has only the ability to report the necessary meta-information to the visualization of spatial data, and for a general query to the underlying factual data. The result, so the card is returned by the WMS usually in a simple raster graphics format, depending on the structure but also various other file formats such as Scalable Vector Graphics ( SVG) or Web Computer Graphics Metafile ( WebCGM ) can be created as for example, is necessary for temporary data with a time reference as a movie. Therefore, the user can make a Web Map Service to address fundamentally via their web browser, in which the card can then be displayed. Thus, the Web Map Service is a component of Web GIS.
Technical background of an OGC-compliant WMS
An OGC -compliant WMS - that is, a Web Map Service that meets the specification of the Open Geospatial Consortium - has three functions that can be requested by a user. Here, so far the communication on the Hypertext Transfer Protocol (HTTP ) as possible. The three functions are sent as HTTP requests from the user to the WMS and are at an OGC-compliant WMS:
Embedding of a WMS into modern geographic information systems
Sometimes a WMS is not used as the sole service in a GI system, but as a component in a complex of various services GIS in which it is only necessary for the display of a map. Accordingly, there are a number of other specifications of the OGC that govern inter alia, access to the underlying spatial data ( Web Feature Service for vector data and Web Coverage Service for raster data) and various other standards in this context.
A WMS is without an intermediary client that gives the user the ability to change the map area ( for example, by moving the map or into the map or zoom out ), barely efficiently.
Enhanced with a tile cache is a WMS to Web Map Tile Service ( WMTS ), Web Map Service caching (WMS -C) or Tile Map Service ( TMS).