The term squitter describes a random data broadcast that can happen either on purpose or due to noise. In aviation, Mode-S transponders play a crucial role by automatically sending out periodic burst transmissions known as squitters. These transmissions are self-generated and do not rely on requests from secondary surveillance radar (SSR) systems.
The information shared in these burst transmissions serves multiple important purposes. One key application is the Airborne Collision Avoidance System (ACAS). Squitter data provides details about an aircraft’s location and vertical speed, helping other aircraft identify potential conflicts in the air.
Another significant use of squitter data is in Automatic Dependent Surveillance Broadcast (ADS-B). An extended squitter consists of messages that relay an aircraft’s identification, GPS position, projected trajectory, and navigation system status. This information is vital for air traffic controllers to track aircraft accurately and ensure safety in the skies.