默认题库 - 雷达及ARPA的使用

单选题

The description Racon beside an illustration on a chart would mean a（）.

A. radar transponder beacon
B. radar conspicuous beacon
C. radar calibration beacon
D. circular radiobeaco

单选题

The radar control that reduces weak echoes out to a limited distance from the ship is the（）.

A. sensitivity time control (sea-clutter control)
B. receiver gain control
C. brilliance control
D. fast time constant (differentiator)

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单选题

The radio waves used for radar are very short，only（）long.

A. a few centimeters
B. a few fathoms
C. a few meters
D. a few feet

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单选题

What will cause the ARPA to emit a visual alarm，audible alarm，or both?（）

An acquired target entering into a guard zone
B. A tracked target lost for one radar scan
C. A tracked target entering your preset CPA-TCPA limits
D. A target being initially detected within a guard zone

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单选题

Which general statement concerning radar is FALSE?（）.

A. Raising the antenna height increases the radar range
B. The ability of radar to detect objects is unaffected by weather conditions
C. Radar bearings are less accurate than radar ranges
D. Radar should be checked regularly during clear weather to ensure that it is operating properly

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单选题

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

A. She must use this equipment to obtain early warning of risk of collision
B. The use of a radar excuses a vessel from the need of a look-out
C. The radar equipment is only required to be used in restricted visibility
D. The safe speed of such a vessel will likely be greater than that of vessels without radar

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单选题

You are underway at 5 knots and see on your radar a contact 10 miles directly astern of you. 12 minutes later，the contact is 8 miles directly astern of you. What is the estimated speed of the contact? （）

A. Dead in the water
B. 1 knot
C. 10 knots
D. 15 knot

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单选题

You are underway in restricted visibility and hear a fog signal forward of the beam. Nothing appears on your radar screen. You must（）.

A. stop your engines
B. sound two prolonged blasts of the whistle
C. sound the danger signal
D. slow to bare steerageway

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单选题

The fitting of an efficient radar reflector is likely to considerably increase the ship’s probability of（）.

A. detection
B. being detected
C. the detective
D. the detected

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单选题

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

A. Starting with a dash and extending radially outward from the target
B. As a broken line from center of PPI to the target
C. Starting with a dot and extending radially inward from the target
D. Starting with a dash and extending to the right of the target

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