Final answer:
The correct answer is d) RADAR-VIS, which is not a secondary method of radar identifying an aircraft. Mode 3/A (IFF), Mode S, and ADS-B are all commonly used methods, but RADAR-VIS is not a recognized term in the radar industry.
Step-by-step explanation:
Physics - High School Level
The correct answer to the question is d) RADAR-VIS. Radar systems use different secondary methods to identify aircraft. Mode 3/A (IFF), Mode S, and ADS-B are all commonly used secondary methods, but RADAR-VIS is not a secondary method of radar identification.
Mode 3/A (IFF)
: IFF stands for Identification Friend or Foe and is a system that enables radar systems to distinguish between friendly and hostile aircraft. It uses a unique 4-digit code called a squawk code to identify aircraft.
Mode S
: Mode S is an enhanced version of the IFF system. It allows aircraft to transmit additional information such as flight identification, altitude, and speed.
ADS-B
: ADS-B stands for Automatic Dependent Surveillance-Broadcast. It is a system that allows aircraft to broadcast their position, speed, and altitude to other aircraft and air traffic control.
RADAR-VIS
: RADAR-VIS is not a valid secondary method of radar identification. It is not a recognized term or acronym in the radar industry.