C3 - Use of Radar and ARPA for the safety of navigation (100)

100問 • 2年前

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1. Your vessel is underway making a speed of around 10 knots. At 1800 hours, you observed a target on your radar dead ahead at a range of 10 nautical miles. At 1812 hours the target is still dead ahead at a range of 8 miles. What is the status of the target?

•about dead in the water

2. How will you avoid the posiibility of errors in bearing when using mechanical bearing cursor in the opration of the RADAR?

•The center spot must be under the centre of the bearing cursor.

3. How long will it takes for the Radar to be fully operational (RUN STATUS) after switching ON from cold?

•Within 4 minutes

4. What ideas justify cause the SART to begin a transmission?

•After being activated, the SART responds to Radar interrogation.

5. What ca you expect from the ARPA target tracking system in auto acquisition mode?

•Small and weak targets may not be acquire

6. What is one good practice of a navigator fixing a vessel position by means of Radar?

•Can use radar information from one object to fix the position

7. The following are navigational systems that work with ARPA EXCEPT:

•Echo sounder

8. How should the signal from a Search and Rescue RADAR transponder appear on a RADAR display?

•A series of 12 equally spaced dots

9. Which of the following will cause the ARPA to emit either or both a visual and audible alarm?

•A tracked target entering your preset CPA/TCPA limits.

10. In calm and clutter free conditions, what is the minimum detection range for X-band radar if the target is a 10-meter tall SOLAS ship (more than 5,000 gross tonnage)?

•11 nm

11. An S-Band radar operates in which frequency band?

•2 - 4 GHz

12. When you are approaching a RACON fitted with a LIGHT, how would the RACON be identified on the radar?

•A coded signal triggered on the same bearing at a greater range than the light

13. What is the approximate wave length of an X-band radar operating on a frequency of approximately 9500MGHz?

•3 cm

14. What is the purpose of radar tracking of other ships?

•To receive information about ships in the vicinity

15. What do you call the target echoes that appear along a line?

•Timebase

16. Which of the following situation will cause the ARPA to emit a visual alarm, audible alarm, or both?

•A tracked target lost for one radar scan

17. What is a situation wherein a radar contact will remain stationary if your radar is on a relative motion display only?

•On the same course and speed as your vesse

18. You have set your ARPA limits defining dangerous targets as CPA range of 3 n.m. and time of CPA of 10 minutes. Which of the following would cause a dangerous target alarm to activate?

•When the acquired target has a CPA of 1.8 nm and a time of CPA of 10 minutes

19. Which of the following is included in the International Regulations for Prevention of Collision at Sea?

•Instructions on action to take while plotting a ship by radar

20. What caused the side echoes on the radar?

•Reflection from the side lobes of the radar beam.

21. In what time frame must an ARPA produce a true motion with 95% accuracy and true course and speed?

•3 minutes

22. With regard to ARPA, what does the "lost target" warning denotes?

•Target can no longer be plotted

23. In the charts, objects are sometimes marked "Racon". What is a Racon?

•A buoy or a lighthouse which is activated by a ship\'s radar and indicate this by a marker on the radar

24. What is the most accurate measurement a Radar can provide?

•Distance to a target

25. What is the IMO requirement for ARPA detection?

•Performance not inferior to the radar display

26. What is the term for the number of pulses sent out by the scanner in one second?

•Pulse repetition frequency

27. What is the range discrimination of a radar set of pulse length 60 meters?

30 meters

28. What ratio would a typical ARPA use before writing a target into the final switch register?

•5 returns to 10 pulses

29. How does height above sea level influence the radar range of detection of a target?

•Higher objects are detected further away than the lower objects

30. What is the minimum display area diameter in the performance requirements for all ships/crafts less than 500 gross tonnage?

•180 mm

31. You are underway at 5 knots and you observe from your radar a target with a range of 10 miles directly astern of you, twelve minutes later, the target is 8 miles directly astern of you. What is the estimated speed of the contact?

•15 knots

32. Indicate three important target data which can be received from radar tracking of other vessel.

•Course, speed and risk of collision

33. Which of the following statements concerning operational requirements for the radar system is TRUE?

•A mininum of four independent parallel index lines, with a means to truncate and switch off individual lines, should be provided.

34. What are the two most important pieces of input information required to operate the ARPA accurately?

•Speed and heading.

35. From which of the following does an ARPA builds up the track history of a target?

•Series of its range and bearings

36. What is one cause of a radar bearing error?

•Misalignment of the center of the trace on the display

37. According to Rule 19 of the COLREGs, what must be your action if you detect another vessel by radar alone?

•Determine if risk of collision exists

38. In what time frame an ARPA should present a steady state tracking the motion of a target with the following accuracy values ( 95% probability values)?

•Within 3 minutes

39. What is the pulse length of a typical radar?

•0.05 to 1.25 microseconds

40. The following are navigational system that work with the ARPA EXCEPT:

•Echo sounder

41. Which part of the ship must the radar transceiver be kept from at a safe distance?

•Magnetic compass

42. Which of the following has the most effect on the size and shape of radar small targets?

•Pulse lenght

43. By radar alone, you detect a vessel ahead on a collision course, about 3 miles distant. Your radar plot shows this to be a meeting situation. Which action should you take?

•Turn to starboard

44. From where are the radar target ranges obtained?

•The range marker

45. What is the radar control to be adjusted so that echoes from rain can be reduced?

•Differentiator control

46. How does a RADAR distinguish separate targets on the same bearing but having small difference in range?

•Radar range resolution ability

47. In radar principles, when would second trace echoes are more likely to occur?

•A high P.R.F. is used.

48. Which radar control that shortens all echoes on the dispaly and reduces clutter caused by rain or snow?

•Fast time constant (Differentiator)

49. Which of the following situation will cause the ARPA to emit a visual alarm, audible alarm, or both?

•A tracked target lost for one radar scan

50. What is dangerous with opeating the ARPA in mixed mode over time?

•Forgetting that this actually is a mixed mode

51. When using the ARPA in heavy rain, which action should you take ?

•Increase the FTC setting to reduce close-in spurious signal

52. Which of these factors would cause blind sectors on the PPI?

•The beam of radar energy is obstructed by a mast

53. How can a rescue personnel detect that a SART is transmitting in the immediate vicinity?

•The SART's blips on the PPI will become arcs and eventually become concentric circle

54. What is the radar control that shortens all echoes on the display and reduces clutter caused by rain and snow?

•Fast time constant (Differentiator)

55. Which of the following radar presentation feature can be used to advantage for position fixing?

•An off-centered display

56. Under COLREGs Rule 7, what is included in the proper use of radar to determine risk of collision?

•Radar plotting or equivalent systematic observation.

57. How often does ARPA extracts range and bearing information?

•Every scan

58. What is called as the rate at which two moving objects approach or separate from each other?

•Relative speed

59. What is the function of the heading flash when the sweep line is momentarily intensified on the PPI presentation?

•To inform the operator of the dead-ahead position on the PPI scope.

60. If your vessel while proceeding North at 15 knots, observed by radar a stationary target, what would be the approximate direction and rate at which the pip would move on your PPI scope?

•South at 15 knots

61. You are scanning the radar screen for a buoy fitted with racon. How should this signal appear on the PPI display?

•Starting with a dash and extending radially outward from the target

62. What should be the range accuracy of a typical radar?

•Within 1.5% of the range scale in use

63. An indirect radar echo is caused by a reflection of the main lobe of the radar beams off the observers vessel. Which of the following is NOT a characteristics of indirect echoes?

•They always appear on a bearing of 90 degrees from the true bearing of the contac

64. When radar display is set so that your vessel appears at the center of the screen and the heading is set to always point to zero degrees , The observed bearings can be defined by which of the following?

•Relative

65. Which radar control is used to adjust the intensity of the illumination of the radar between radar images and background of the screen?

•Contrast

66. The ship's speed indication on the ARPA display can be set manually but does not change with changes in the vessel's speed. What other indication would point to a related equipment failure?>

•"LOG OUT" is displayed on the ARPA indicator

67. How is a true motion shown in a radar display?

•A target's actual movement.

68. What is the minimum size of the vessel that requires 9 GHz radar system to be fitted?

•300 GT

69. Which statement is TRUE concerning risk of collision?

•Proper use shall be made of radar equipment to determine risk of collision is developing

70. What should you do to ensure that the RACON signal is displayed on the radar?

•Turn off the interference controls of the radar

71. Short range resolution or pulse length will have what kind of an effect on the appearance of targets on the radar scope?

•Targets will appear shallower in depth

72. Which of the following has the most effect on the size and shape of small radar targets?

•Pulse length

73. Your vessel is making 10 knots . After several observation of a target, it remain in the same position relative to yours, what could be the possible analysis of the situation?

•The target is on the same course and speed as your vessel

74. You are using a radar which your own ship is shown at the center, and the heading flash always points to 0degree. If bearings are measured in relation to the flash, what type of bearings are produced?

•Relative bearing

75. You are underway making 10 knots through the water, and after several observation a target remain in the same position relative to yours, what could be the possible conclusion of the scenario?

•The target is on the same course and speed as your vessel

76. What circuit controls the suppression of sea clutter

•STC circuit

77. If your vessel, while proceeding South at 10 knots, observed by a radar a vessel proceeding South at 10 knots, what would be the approximate direction and rate at which the pip would move on your PPI scope?

•Stationary

78. Which mode of the ARPA that when it is used properly, it will produce greater accuracy?

•Ground stabilized

79. If there is another ship overtaking you close to starboard, and you have three radar targets bearing 90 degrees relative at ranges 0.5miles, 1.0miles and 1.5 miles. In this case what are the unwanted echoes?

•Multiple echoes

80. What must be the size of the radar beam to provide accurate target bearings?

•Narrow in the horizontal plane.

81. In what time frame must an ARPA produce a relative motion with 95% accuracy and CPA/TCPA?

•1 minute

82. Trial maneuver in ARPA fitted on vessels of over what tonnage

•10,000 gt

83. What must be the minimum activated AIS target capacity of an ARPA?

•40 targets

84. What is the factor in determining a radar maximum range?

•Receiver sensitivity

85. When navigating in thick fog with the radar on, which action should you take?

•Station a look-out as low down and far forward as possible

86. What do you call a radar display which is oriented so that north is always at the top of the screen?

•Stabilized display

87. Which statement is TRUE concerning a vessel equipped with operational radar?

•She must use this equipment to obtain early warning of risk of collision

88. What would mean the description "Racon" beside an illustration on a chart?

•Radar transponder beacon

89. What do you call the marker in the radar PPI which the operator can put in any direction to watch the incoming target?

•Guard zones

90. What is the radar control used to reduce sea clutter?

•Sensitivity time control

91. It is a device for transmitting coded signal in response to a signal interrogated by radio direction and ranging equipment from the vessel.

•RACON

92. Which of the following has the most effect on the definition of small target on the radar display?

•Horizontal beam width

93. When on automatic tracking operation, how would the two targets presented by ARPA may swap information?

•When passing close together.

94. What should you do in order to ensure that a RACON signals displayed on the radar

•Turn off the interference controls on the radar

95. According to the requirement of the Rules, which factor to be taken into account when determining safe speed?

•The location of vessels detected by radar

96. What happened when radar waves are trapped in the atmospheric duct?

•Increase of radar range

97. What should be done in order to ensure that the RACON signal is visible on your 3 cm radar?

•Rain clutter control should be off but, if necesssary may be on low

98. What is the purpose of the function "Anti-sea clutter" in the radar?

•Reduce the sea echoes

99. How can risk of collision can best be assessed if your vessel is underway in restricted visibility?

•Watching the targets radar bearing and range

100

100. What is the radar presentation feature which is useful in radar pilotage?

•True motion

C1 - Plan and conduct a passage and determine position (200)

Joedz Padin · 100問 · 2年前

C1 - Plan and conduct a passage and determine position (200)