問題一覧
1
The figure below is an example of:
C. a SART
2
The purpose of the T/R CELL is to:
B. Protect the receiver during transmission.
3
The purpose of the gain control is to adjust:
A. the amplification of the target echoes
4
The tuning control adjusts:
A. the frequency of the receiver
5
When ducting occurs the radar beam:
B. carried long distances between air layers
6
Indirect echoes are caused by reflections from:
B. obstructions close to the scanner
7
Minimum range dependes mainly on:
C. pulse length
8
A vessel equipped with both a 10 cm and a 3 cm radar. One would expect the 3 cm radar to provide better:
A. range discrimination
9
The theoretical detection range of an object 81 metres high, from a ship with an aerial 16 metres above sea would be:
A. 29 miles
10
A small GRP vessel is considered a poor radar target mainly because:
A. GRP is transparent to radar energy
11
Range discrimination between two targets at about 8 miles on the display can beimproved by:
B. reducing pulse length
12
If an echo appears in a shadow sector you could check if it was a real echo by:
C. altering course
13
Increasing the sea clutter control:
B. reduces amplification of close echoes
14
A rasterscan radar differs from a analogue radar in that:
A. the screen is rectangular
15
The figure below could be an example of:
B. side echoes
16
The figure below is that used by the IMO to indicate:
B. short pulse
17
The figure below is that used by the IMO to indicate:
C. ships head up
18
The figure below is that used by the IMO to indicate:
B. scale illumination
19
The figure below could be an example of:
A. a multiple echoes
20
The figure below is that used by the IMO to indicate:
C. range
21
The figure below is that used by the IMO to indicate:
A. VRM
22
A higher screen resolution would mean that the display would be:
B. sharper and clearer
23
LCD means:
C. Liquid crystal display
24
A analogue radar differs from a rasterscan radar in that:
A. the display must be viewed through a hood in daylight.
25
Altering the range scale may automatically change the:
B. pulse length
26
Radar uses pulse transmission in order to:
B. detect close targets
27
The figure below represents the radar display of a vessel steering 270D. What type of display is it?
A. north-up
28
You have a radar target at a range of 7 miles on your starboard bow, when you hear a fog signal apparently forward of your beam. You must:
C. slow to mere steerage way
29
You are in restricted visibility and have plotted a target on your starboard quarter and determined that the overtaking vessel will pass at a CPA of 0.2 miles on your port side. You must:
C. alter course to port increase the CPA
30
You are in restricted visibility and have plotted a target on your port bow and determined that the approaching vessel is on a collision course. You must:
C. alter course to starboard or reduce speed or stop
31
You would expect rain to have a greater affect on a 3 cm radar than on a 10 cm radar
B. yes
32
Your radar has a beam width of 4°, you measure the relative bearing of a large headland fine on the starboard bow to be 123 T. What is the corrected bearing:
B. 125 degrees
33
Range discrimination is the ability of the radar to distinguish between two targets:
B. on the same bearing but slightly different ranges
34
Bearing discrimination is the ability of the radar to distinguish between two targets:
A. on the same range but slightly different bearings
35
Beam width distortion occurs because:
C. the radar beam is a finite width
36
Side echoes are caused by:
B. echoes from the side lobes of the radar
37
The strength or power of a radio wave is known as it’s
B. Amplitude
38
A 10 cm radar transmits in the
C. s band
39
Beam width distortion can be improved by
B. reducing the gain
40
The figure below is an example of:
C. mutual interference
41
The formula for echo-ranging principle is:
B. d = (t×s) / 2
42
The heading marker off switch is used to:
B. search for weak targets dead ahead
43
The energy used by radar to detect targets is in the form of a:
B. radio wave