ADS-B Compliance is here now and you need to be in compliance. ADS-B or Automatic Dependent Surveillance-Broadcast is a primary technology supporting the FAA’s Next Generation Air Traffic Control System, or NextGen. This shifts an aircraft’s separation and air traffic control from ground-based radar to satellite-derived positions. Most importantly ADS-B Out broadcasts an aircraft’s WAAS-enhanced GPS position to the ground, where it is displayed to air traffic controllers. It’s also transmitted to aircraft with ADS-B receivers, either directly or relayed by ground stations, to allow self-separation and increase situational awareness.
There are two paths to compliance, 978UAT or 1090ES. A universal access transceiver, or UAT, operates on 978 MHz (978UAT). UAT equipment costs generally are lower, and this frequency receives free weather information (Not all UATs support the optional ADS-B In.)
The 1090ES datalink uses a Mode S Extended Squitter transponder (1090MHz: “ES” refers to ADS-B information appended to the Mode S data).