8-1A: Marine RADAR Systems

Question 1

8-1A1

Choose the most correct statement containing the parameters which control the size of the target echo.

A. Transmitted power, antenna effective area, transmit and receive losses, RADAR cross section of the target, range to target.
B. Height of antenna, power radiated, size of target, receiver gain, pulse width.
C. Power radiated, antenna gain, size of target, shape of target, pulse width, receiver gain.
D. Magnetron gain, antenna gain, size of target, range to target, wave-guide loss.

Answer 1

ANSWER A
The size and signal strength of a RADAR target echo may be determined by the target cross sectional area, range to the target, transmit and receive path losses, RADAR antenna effective area, and your transmitter power output. Some of the other answers look pretty good, but go with answer A, and look at the drawings to see why distant small targets appear and disappear on the display! Antenna effective area are the key words in the correct answer!

Question 2

8-1A2

Which of the following has NO effect on the maximum range capability?

A. Carrier frequency.
B. Recovery time.
C. Pulse repetition frequency.
D. Receiver sensitivity.

Answer 2

ANSWER B
Maximum range of a RADAR system IS influenced by peak poiwer output, receiver sensitivity, pulse repetition frequency, and the RADAR band frequency of operation. But the question asks what has NO effect on maximum range, and that would be RECOVERY TIME. Recovery time is associated with the MINIMUM range calculations as a period of time where the receiver is unable to receive the echo, a function of the TR tube to respond to within 6 dB of normal sensivity at the conclusion of the transmitter pulse. Recovery time would not factor in maximum range capability.