I'm playing at the moment a little bit with SDR. One of the nice things is that you can use it to receive ASD-B information. This is a system that send (beside other information) the position and altitude of an aircraft. This capability is part of future traffic control systems, just in case you are wondering why aircrafts are doing this. However: The information is unencrypted and anybody can receive it. You just need a RasPi, an antenna and a DVB-T stick with a certain chipset and a program called dump1090.
However i thought "Joerg, you have access to the raw data of your own receiver. Let's play with that". And this is the result. It's 24h worth of air traffic from the 19.7.2016 17:00 to the 21.7.2016 17:00. You can click on it to get the fullsize result.