ADS-B is a civil aircraft tracking and telemetry standard that the FAA has ruled will replace transponders by 2020. Like a transponder, it’s used to identify air traffic, but with far more more information, such as altitude, heading, speed, and GPS location. The protocol also supports delivery of weather, terrain, and notices to aircraft. The ADS-B signals from aircraft in the sky are intended for receipt by both air traffic controllers on the ground and by other aircraft in the vicinity.
All of this almost adds up to a mesh network of aircraft and ground stations. The ground stations use it to manage air traffic and aircraft with ADS-B displays in their radio stacks use it to avoid collisions with each other, the ground, and adverse weather. The usage and protocols are very specific, but it’s almost an internet in the sky. It’s certainly very close to making aircraft part of the internet of things.
Richard Osgood and Hack-a-Day aren’t into the IoT angle yet, they’re in pure mind blown mode about how easy it is to receive the signals. Richard’s how to video demonstrates that ease, and his pointers to software (Zadig, ADSBSharp, and ADSBScope) are more than helpful. This software radio tuner looks to be about right, but I haven’t tested it myself. Meanwhile, Flip That Bit and IK1ZYW have both shared pictures and diagrams of their 1090MHz-optmized antennas for ADS-B reception.