The Google Earth API is expected to be shut down at some point in the near future. As of this writing it is still working. We have been investigating what alternatives exist for those wishing to create applications that work with Google Earth. If you just wish to control the view in Google Earth then one possibility is via the Liquid Galaxy protocol. For more advanced applications it may be possible to take advantage of the fact that Google Earth has a built-in browser used to render its popups. We already demonstrated a mini-application that shows a Google Map in a popup and had a look at a more advanced application, OpenForis, that makes great use of popups.
To try it out download this KML file. Switch to historical imagery and find an interesting location. You should see a popop at the bottom left of the screen. First check the Google Earth timeline toolbar to see what dates are available and choose two dates that you are interested in. Enter the two dates in the popup as well as the altitude in km. Use the same date format as shown on the timeline toolbar. For best results you can use the ‘eye altitude’ shown at the bottom right corner in Google Earth. Click the ‘Update’ button.
Next, move the view slightly, which will cause the network link to refresh. You should now see a tour in the network link. Play the tour. For best results set the tour to repeat .
Let us know in the comments if you encounter any bugs.
Our next task will be to work out how to estimate the correct eye altitude given a particular set of view coordinates.