2009년 12월 5일 토요일

OGC WMS Operation Quick Reference

웹을 통해 지도 형식(이미지-png, jpg, gif 등)으로 GIS 데이터를 접근하기 위한 인터페이스

WMS 클라이언트는 어떤 GIS 데이터를 원하며 지도에 어떤 형식으로 표현될 것인가를 지정(SLD)하고 서버는 클라이언트의 요청에 맞게 지도를 구성하고 이를 반환

◎ WMS operation

 Request Response Description
 GetCapabilities XML 서비스 가능한 레이어의 메타정보 반환
 GetMap Image 요청한 레이어의 공간정보를 이미지로 반환
 GetFeatureInfo XML 요청한 위치의 피쳐 정보를 반환
 GetLegendGraphic Image 요청한 레이어의 범례정보를 이미지로 반환
 GetStyle XML 요청한 레이어의 스타일 정보를 반환
 PutStyle XML 요청한 레이어의 스타일 정보를 등록

◎ Basic WMS

A basic WMS shall support the basic service elements, the GetCapabilities operation, and the GetMap operation.


○ GetCapabilities

The purpose of the mandatory GetCapabilities operation is to obtain service metadata, which is a machine-readable (and human-readable) description of the server's information content and acceptable request parameter values.

예)

http://hostname/wmsservice?VERSION=1.3.0&REQUEST=GetCapabilities&SERVICE=WMS&

 

○ GetMap

The GetMap operation returns a map. Upon receiving a GetMap request, a WMS shall either satisfy the request or issue a service exception.

예)

http://hostname/wmsservice?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&LAYERS=Oceans,Countries,Cities&STYLES=&SRS=EPSG:4326&BBOX=-124,21,-66,49&WIDTH=600&HEIGHT=400&FORMAT=image/png&TRANSPARENT=True


 ◎ Queryable WMS

A queryable WMS shall satisfy all the requirements for a basic WMS, and shall also support the GetFeatureInfo operation.


○ GetFeatureInfo

GetFeatureInfo is an optional operation. The GetFeatureInfo operation is designed to provide clients of a WMS with more information about features in the pictures of maps that were returned by previous Map requests. The canonical use case for GetFeatureInfo is that a user sees the response of a Map request and chooses a point (I,J) on that map for which to obtain more information.

예)

http://hostname/wmsservice?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetFeatureInfo&SRS=EPSG:4326&BBOX=-117,38,-90,49&WIDTH=600&HEIGHT=400&QUERY_LAYERS=States&X=200&Y=150&


◎ Operation 구현 참고

http://www.opengeospatial.org/standards/wms

http://www.opengeospatial.org/standards/sld

http://www.opengeospatial.org/standards/symbol

http://www.opengeospatial.org/standards/gml

http://www.opengeospatial.org/standards/sfa

http://www.opengeospatial.org/standards/common