Did you know that you can now track aircraft on a radar screen or map just like air traffic controllers but with much more information. You can look up the aircraft registration, its manufacturer and model and where it’s flying to and from. All from the comfort of your armchair or even at the airport

All this is possible with the advent of ModeS/ADS-B data transmitted at 1090 MHz and the increasing range of low cost receivers to translate the broadcast data.

The fundamental concept of Mode S is the assignment of a unique ICAO 24-bit address to an aircraft. This address is often referred to as ModeS or Hex code.

Mode S is a Secondary Surveillance Radar technique that permits selective interrogation of aircraft by means of the unique 24-bit address, thus avoiding the risk of confusion or mis-identification due to overlapping signals

Radarspotting is highly addictive so be warned!