Avionics Practice Test: Surveillance Systems, Mapping and Multimode Radars — Flashcards

Surveillance Systems, Mapping and Multimode Radars topics include: Electronic scanned array radar, primary and secondary radar, modes s system, traffic alert, collision avoidance system and weather radar.

Multi-mode radars are radars that can operate in multiple modes at the same time. They are typically used for military applications such as search and track operations or air defense missions.
The Mode S system is a secondary surveillance and communication system that supports Air Traffic Control (ATC). It is a Secondary Surveillance Radar process that allows selective interrogation of aircraft.

An aircraft collision avoidance system (ACAS) is a family of airborne devices that help pilots avoid mid-air collisions. ACAS works independently of ground-based air traffic control (ATC) and can help a variety of aircraft types. 
ACAS uses various technologies and sensors to detect an imminent crash, including: Radar, Laser (LIDAR), Cameras, GPS sensors. 
ACAS warns pilots of the presence of other aircraft that may pose a collision threat and recommends a maneuver to reduce the risk if it's imminent. Pilots must use the system and respond to resolution advisories to achieve its full safety benefits. 
In Europe, ACAS/TCAS is estimated to reduce the risk of mid-air collisions by about 5.

Related Test: Aircraft Maintenance Practice Test: Weather Radar