A, OGC Web services specifications
In distributed GIS, interoperability aspects, some organizations (such as OGC, UCGIS, etc.) is to develop appropriate standards and some pilot projects, which developed a series of OGC specifications in terms of spatial information Web Services.
1.OWS service system
In OWS service system, the main part as follows:
- Geographic Data Services: providing services for spatial data; mainly the WFS (vector data services), the WCS (raster data service), the result returned is usually geographic service data with the spatial reference system.
~ Map depicts the services: the depiction of spatial data, there are WMS (map service). Wherein the map may be combined together by a plurality of layers, each map can be described by the map SLD. Map services are usually the result of vector graphics or raster graphics
~ During the processing services: find, index, and other geographic data services, mainly Geocoder (geo-coding services o), Gazetteer (Gazetteer service), Coordinate Transfer Service (coordinate conversion service), etc.
~ Posted registration services: providing registration services for various services, in order to discover the service. Wherein the service includes registration data types, data instance, service type, service instances. Registration registration service provides each registration, update and lookup services.
~ Client application: the basic applications of the client, such as a map display, map browsing and other value-added services. (OpenGIS Services Framework in the client application, also known as client applications, client-server application called application server-side, they are on the network server rather than on the user's desktop or handheld device.)
2.OGC approach to service
OGC has developed a lot of geographic service standards, it is generally provided in two ways: based on HTTP calls for service and style SOAP (XML-based call) Web services.
Like other Web services, the core of the geographical information can also be expressed with the interface, the same services must implement the same interface, you can have inheritance relationships between interfaces.
