WMS (Web Map Service)

WMS (Web Map Service) is an Open Geospatial Consortium (OGC) standard protocol for serving raster images over the web. WMS is the most popular format you will encounter when accessing governmental or other public web data repositories. The images are usually backed by a GIS database and generated on demand, though the server may also be configured to serve pre-tiled data.

There are many options for WMS access, and many versions of WMS, and osgEarth only supports a small subset as described below.

WMSImage

CLASS: WMSImageLayer (inherits from ImageLayer)

Property	Description	Type	Default
url	Location of the WMS service	URI
format	Image format to generate, usually at a mime-type. Commonly supported formats include jpg and png (some WMS servers expect the mime-type format like image/jpeg or image/png instead)	string
layers	WMS LAYERS option (see specification) and requests the data be generated from a given layer or comma-separated collection of layers	string
srs	WMS SRS option (see specification) as exposed in the capabilities response, and refers to the spatial reference system of the image to generate	string
transparent	Hint as to whether the server should create imagery with a transparency channel (alpha). This requires the use of a format that supports alpha (like png)	boolean	false
crs	WMS CRS option (see specification) as used by later WMS versions as a refinement of the old SRS option.	string
style	WMS STYLES option (see specification) to request from the server	string
capabilities_url	Optionally specificy the URL osgEarth should use to request server capabilities. Usually this is devined automatically and you do not need to set it.	URI
wms_version	Expressly request a WMS version string from the server; usually you do not need this, but sometimes a WMS server requires it.	string	1.0.0

Example

<WMSImage name="Weather RADAR">
    <url>http://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n0r.cgi</url>
    <format>png</format>
    <layers>nexrad-n0r</layers>
    <srs>EPSG:4326</srs>
    <transparent>true</transparent>
</WMSImage>