Web Map Service (WMS)
Overview
Web Map Service (WMS) is a standard protocol developed by the Open Geospatial Consortium (OGC) for serving georeferenced map images over the internet generated by a map server using data from a GIS database. WMS returns rendered images (PNG, JPEG, GIF) rather than raw data, making it suitable for displaying pre-styled map layers in web applications.
Key Concepts
GetCapabilities is an operation that returns metadata about the WMS service, including available layers, supported formats, and coordinate systems. GetMap is the primary operation that returns a map image based on specified parameters (layers, extent, size, format). GetFeatureInfo is an optional operation that returns attribute information about features at a specific location. Layers are named collections of geographic features available from the service. Styles define how features are rendered visually (colors, symbols, line widths).
Request Parameters
| Parameter | Description |
|---|---|
SERVICE | Service type (WMS) |
VERSION | WMS version (1.1.1, 1.3.0) |
REQUEST | Operation name (GetMap, GetCapabilities) |
LAYERS | Comma-separated list of layer names |
BBOX | Bounding box coordinates |
WIDTH / HEIGHT | Image dimensions in pixels |
FORMAT | Output format (image/png, image/jpeg) |
CRS / SRS | Coordinate reference system |
Appendix
Created: 2025-12-13 | Modified: 2025-12-13