Where To Begin With KML

KML stands for Keyhole Markup Language. It is an eXtensible Markup Language (XML), that used to create content for Google Earth and other geobrowsers. It was initially developed by Keyhole Inc., who where purchased by Google Inc. in 2004, and then by Google themselves. In 2008 the Open Geospatial Consortium (OGC) ratified KML as an international standard, and the official reference specifications are now under OGC's control. However, new KML, such as functions in the Google Earth 5 Tour Function, continue to be developed by Google using namespace extensions.

 

Getting Started with KML

KML stands for the Keyhole Markup Language and is the international standard code used by Google Earth to generate and display content. Many KML features can be created and edited through the Google Earth interface, but its full abilities are unlocked through direct editing of the code.


  • A good place for both code monkeys and others who wish to learn KML at the text editor level is The KML Handbook by Josie Wernecke.

  • Google's code pages offer tutorials on basic and advanced KML features and documents with additional information on key elements in KML.

  • For more examples of KML illustrated using the GE plugin, see Roman Nurik's KML Interactive Sampler.

Editing KML

Some popular free or shareware text editors:

       jEdit (download)
       <oXygen/> (download)
       Crimson Editor (download)

When editing a KML file and viewing the effects of changes in Google Earth, there are two useful tricks to remember:

  1. Cut/Copy/Paste can be used to take a KML file in "Places" and view the code in a text editor. The reverse can also be done; code can be pasted diectly into "Places" and the KML objects it creates will appear in the 3D browser.

  2. If the same file is open in both Google Earth and a text editor, when changes are saved in the latter, the view in Google Earth can be updated by using "revert" (right-click on the filename).
 

Links

KML Tools

KML Colors - a pallette of KML (ααbbggrr) codes and their HTML and RGB equivalents

Photo Overlay creator - this program creates <PhotoOverlay> 2D rectangles, or as images projected onto cylinders and spheres creating virtual panoramas. It also optimizes large (megapixel) PhotoOverlays for low bandwidth environments.

Screen Overlay Maker - a tool to make a <ScreenOverlay>, which cannot be done directly in Google Earth.

EarthPlot and Paint - a toolset for creating <GroundOverlay>s using various image files or freehand shape drawing.


KML Examples

Google Earth Gallery
Google's collection on user-created KML. Files a grouped into several broad categories: Featured, Popular, Educational, Travel, Fun, Sky and Ocean.

Google Earth Library
A collection of KML optimised for use in Google Earth. Covers a range of subjects but has a particular interest in mapping, especially topographic and geologic maps.

Google Earth Blog - Science Archives
Frank Taylor's blog post on interesting and innovative KML visualing scientific data.

KML Archive
A collection of the "best" Earth Science KML created by university researchers, government agencies, citizen scientists and others. This project is still in beta development.