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Radar — Navigation B — Instruments, Mashit 30

17 questions on radar, from the Navigation B — Instruments exam of Mashit 30. Range, discrimination, controls and detecting risk of collision. Every question is shown with its correct answer, as in the official question pool.

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Questions on Radar

  1. What do you need to check whether there is a risk of collision with a vessel nearby? A hand-bearing compass, a watch, at least 3 bearings of the vessel being checked, and the ability to judge the range.
  2. What is radar used for? All of the above.
  3. Can aircraft and rain clouds be detected by radar? Yes, but only at heights within the vertical beamwidth of the radar.
  4. What does the detection range of a radar depend on? The antenna height, the transmitter power, and weather and atmospheric conditions.
  5. What is the GAIN control on a radar used for? To reduce or increase receiver sensitivity.
  6. In heavy rain, can small vessels and a marina entrance be detected on radar, and which control on the control panel should you use? Yes, but it depends on the size and material of the objects and on how heavy the rain is; the right control is Anti-Clutter Rain or FTC.
  7. The quality and detection range of an object on radar depend on: All of the above.
  8. What do you need to detect a risk of collision on radar? All of the above.
  9. STAND-BY mode on a marine radar: The radar neither transmits nor receives, but the screen is "warm" and ready for immediate use.
  10. What is the difference between a RADAR REFLECTOR (the first) and a SART (the second)? All of the above.
  11. On the radar, 2 targets that are physically close to each other lie on the same bearing. When will they be better distinguished? When the transmitted pulse length is shorter.
  12. What is the effect of the bending of radar waves? Answers b and c are correct.
  13. What is radar used for? Collision avoidance, navigation, route planning, and search and rescue.
  14. In heavy rain, can small vessels and a marina entrance be detected on radar, and which control on the control panel should you use? Yes, but it depends on the size and material of the objects and on how heavy the rain is; the right control is Anti-Clutter Rain or FTC.
  15. Choose the statement about marine radar that is most correct: On short range scales we select a short pulse to separate close objects well, and we also get better bearing accuracy; on long range scales we prefer a longer pulse for good echoes from small objects, but bearing accuracy is poorer.
  16. What do the quality and detection range of an object on radar depend on? All of the above.
  17. When can you tell from the radar that your vessel is at risk of collision? When the target's bearing stays steady and the range decreases.

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