GROL Marine Electronics and Radar Systems

Question 1

What is the primary frequency band used by marine radar systems?

Accepted Answer

X-band (9–10 GHz)

Answer

HF (3–30 MHz)

Answer

VHF (30–300 MHz)

Answer

AM broadcast band (535–1705 kHz)

Question 2

What does ARPA stand for in marine radar terminology?

Accepted Answer

Automatic Radar Plotting Aid

Answer

Advanced Radio Position Antenna

Answer

Auxiliary Radar Processing Amplifier

Answer

Automated Range and Position Analyzer

Question 3

Which type of radar display shows the ship's own position at the center with north always pointing up?

Accepted Answer

True motion display

Answer

Relative motion display

Answer

Head-up display

Answer

Course-up display

Question 4

What is the purpose of the sea clutter (STC) control on a marine radar?

Accepted Answer

To reduce echoes caused by wave returns close to the ship

Answer

To increase transmitter power near land

Answer

To eliminate interference from other radar stations

Answer

To adjust the antenna rotation speed

Question 5

What is the typical pulse repetition frequency (PRF) for a short-range marine radar setting?

Accepted Answer

1,500–4,000 Hz

Answer

100–200 Hz

Answer

500–800 Hz

Answer

10,000–20,000 Hz

Question 6

What is the function of the magnetron in a conventional marine radar transmitter?

Accepted Answer

To generate the high-power microwave pulses

Answer

To amplify received radar echoes

Answer

To rotate the antenna

Answer

To convert AC power to DC for the display unit

Question 7

In marine radar, what does 'minimum range' refer to?

Accepted Answer

The closest distance at which the radar can detect a target

Answer

The farthest distance the radar can reliably detect a target

Answer

The range at which beam power is reduced by half

Answer

The distance at which sea clutter is automatically suppressed