問題一覧
1
To ensure that a RACON signal is visible in the 3cm. radar, one should ensure that the
rain clutter control should be placed on low if nece
2
As per Solas V regulations safety of navigation a ships of 10,000 gross tons and above shall be fitted, with radar capable of operating in the:
9 GHz frequency band
3
The common frequencies used in merchant radar are approximately:
3,000 and 9,000 mega cycles
4
What does an automatic identification system (AIS) transponder use to transmit and receive information broadcasts?
156.525 MHz, 161.975 MHz and 162.025 MHz
5
If the Radar scanners of one vessel are in the same horizontal plane as the cargo deck of the other during transfer operations, which type of radar emissions would pose a greater danger of the induced ignition of flammable vapors?
a 10 cm radar
6
Which is the most accurate position by radar fixes?
radar range and visual bearings
7
This type of radar enhance to maximum visibility in marginal weather condition
S-Band
8
Echoes in radar from two or more targets close to each other at the same range may emerge to form a single echo. The ability of a radar to separate this is called:
resolution in bearing
9
The ability of a radar to separate targets close together on the same bearing is called:
resolution in range
10
Which is the most accurate position by radar fixes?
radar range and visual bearings
11
This type of radar enhance to maximum visibility in marginal weather condition.
S-Band
12
Echoes in radar from two or more targets close to each other at the same range may emerge to form a single echo. The ability of a radar to separate this is called:
resolution in bearing
13
The ability of a radar to separate targets close together on the same bearing is called:
resolution in range
14
The characteristics on which bearing resolution depends is:
horizontal beam width
15
Which indicates that your radar needs maintenance?
Serrated range rings
16
Which radar control is used to shorten all echoes on the display and reduces the clutter caused by the snow or rain?
fast time constant
17
When navigating in coastal waters which of the following is not considered as a factor?
Radar is only supplement to visual fixing
18
Raster‐scan chart data is:
a digitized "picture" of a chart in one format and on
19
This may occur when a strong echo is received from another ship at close range
multiple echoes
20
This is the decrease in the strength of a radar wave resulting from absorption, scattering and reflection by the medium as it passes the atmosphere.
Attenuation
21
The unit which sends returning target echoes to the receiver is the:
scanner unit
22
What do you call the marker in the radar PPI which the operator can put in any direction to watch the incoming target?
Guard Zone
23
The difference in intensity of the illumination of the radar scope between radar images and the background of the screen.
contrast
24
In confined waters which of the following equipment becomes more reliable in obtaining vessel's position?
Radar X band and visual method
25
An identification of ships, coastal areas and other targets, good range and range resolution are important because they:
help indicate maximum detail
26
Most commonly, ship's radar operates in the:
X-Band
27
Which of the following is the best to obtain vessel's position during poor visibility?
Radar
28
Which bridge equipment is used in determining the distance to and direction of objects by sending out a beam of microwave radio energy and detecting the return reflections?
RADAR
29
While underway, a vessel over 100,000 gross tons with an automatic identification systems (AIS) is expected to broadcast all of the following information every 1 to 10 seconds EXCEPT:
name of vessel
30
On a relative motion radar, the closest point of approach (CPA) of a contact is determined
after the contact has been marked at least twice
31
When may the automatic identification system (AIS) be switched off?
At the Master's professional judgement
32
This radar unit performs a dual function both in transmission and reception
scanner
33
Navigation at coastal waters, radar is generally used to supplement
Visual fixing
34
The intensity of the election beam in the C.R.T. is controlled by:
varying the potential on the grid
35
The minimum range at which a target can be detected is basically determined by which of the following?
pulse length
36
The transmission time duration of a single pulse of radio‐frequency energy is a function of the
pulse length
37
In marine navigation, radar signal is
pulse modulated
38
PPI display of a radar means:
plan position indicator
39
The description "Racon" beside an illustration on a chart would mean a:
radar transponder beacon
40
Which of the following is NOT recommendable to obtain vessel's position as radar target?
Floating aids
41
Which of the following is correct concerning RAMARK?
RAMARK is a radar beacon which transmits either c
42
This is defined as the radar control that reduces weak echoes to a limited distance from the ship
sensitivity time control (sea‐clutter control)
43
The scattering and absorption of the energy in the radar beam as it passes through the atmosphere is called:
attenuation
44
Which is the name of movable, radial guide line used to measure direction in the radar?
VRM
45
Countries are producing unique digital charts based on their interpretation of IHO standards:
S‐57 standards
46
Which device emits a characteristic signal when triggered by a ship's radar?
RACON
47
This safety device when activated in a distress situation responds to radar interrogation by transmitting a swept frequency signal which generates 12 blips code on a radar screen
Search and rescue radar transponder
48
Which term refers to the combination of a Radar transmitter and receiver?
transceiver
49
Spoking would be indicated on the radar receiver by
random, pie‐shaped wedges on the PPI
50
In ARPA, which of the following is TRUE?
successive bearings of a pip in radar does not neces