Super-Overlays

GeoWebCache can automatically convert your raster or vector data into super-overlays for integration with Google Earth.

What Are Super-Overlays?

Super-overlays are used to efficiently publish large sets of imagery. A super-overlay is a form of KML (the markup language used to interact with Google Earth) in which data is broken up into regions. This allows Google Earth to request only particular sections of the map when the view area (or zoom level) changes, as opposed to working with the entire dataset.

Generating a Super-Overlay

The following URL structure is used to generate a super-overlay.

http://EXAMPLE.COM:PORT/GEOWEBCACHE_PATH/service/kml/YOUR_LAYER.FORMAT.kml

where:

• EXAMPLE.COM:PORT is the url for your instance of GeoWebCache
• GEOWEBCACHE_PATH is the full path to your GeoWebCache instance (Examples: /geowebcache or /geoserver/gwc)
• YOUR_LAYER is the name of your layer (Example: topp:states)
• FORMAT is the format of the tiles (Examples: jpeg, png)

Omitting the FORMAT (YOUR_LAYER.kml) will set the format of the tiles to the default MIME type in the configuration.

More Information

For more information about super-overlays, please see Google's documentation.

See also an example of using GeoWebCache with Google Earth.