De colored circles are measuring units. The numbers in the circles are the currently measured sound levels. As more sound is measured, the spheres grow and become more dark. Click on a circle for a graph. Red airplaines are climbing, blue ones are in decent. Green airplaines fly at high altitude (transit). Also viewable in Google Earth (use latest Google Earth version if you experience difficulties).
1. Where does this information orginate?
Airplanes broadcast this information (beaconds) to let everybody know where they are, so that mid-air collisions can be avoided. The received beacons are stripped from all information not necessary for this application. Anyone who buys a receiver for a few hundred euros can receive a lot more information from airplaines without any delay. More information about transponders.
2. Is the data complete and accurate?
Not all airplaines are equipped with a transponder that sends out the proper information (Mode S). Most small airplaines don't have a transponder at all. Sometimes a transponder send out signals that deviate from their actual position so that an airplaine seems to land just besides the landing strip.
3. Why does the Google Earth application stop after half an hour?
We try to limit this service (and traffic) to computers with people that actually look at the screen.
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- Technique
- Aviation products
