問題一覧
1
Which mode of ARPA that when it is used properly, it will produce greater accuracy?
Ground Stabilized
2
Which of the following has the most effect on the size and shape of radar small targets?
Pulse length
3
What is the common radar frequency ranges of bands used in coastal radar systems?
3-30 MHz
4
What is the ability of the radar set to clearly distinguish two targets, on the same range and slightly different bearings, as two separate targets from the PPI?
Bearing discrimination
5
In calm and clutter-free conditions, what is the minimum detection range for S-band radar of the target is a 4-meter tall small vessel with radar reflector meeting IMO Performance Standards?
3.7 nm
6
Given the alteration of your own ship's course and speed required, from where can the desired Closest Point of Approach (CPA) be obtained?
Radar plot
7
What is the minimum acquired radar target capacity in the performance requirements for all ships/crafts of 500 gross tonnage an upwards but less than 10000 gross tonnage?
30
8
What is the minimum size of the vessel that requires 9GHz radar system to be fitted?
300 GT
9
What caused the presentation of coral attols or a chain of island as a long line rather than as an individual target?
The effects of beam width
10
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.
11
Which determine the minimum range at which a target can be detected?
Pulse length
12
In a radar system constant, what is the typical pulse repetition frequency?
500 to 3000 pulses per second
13
What is the modulation frequency of most radar systems?
Between 60 and 500 Hz
14
What is the major component of a radar system which amplifies the weak echoes received thus retaining its distinct shape?
Indicator
15
Which of the following do radar bearing discrimination mainly depends on?
Horizontal beamwidth
16
What is the minimum acquired radar target capacity in the performance requirements for all ships/crafts of less than 500 gross tonnage?
20
17
Which of the following condition will happen if you turn on the fast time constant differentiator control on the radar?
There is a better appearance definition
18
Identify the correct manual plot vector label that best represents an ARPA relative vector information?
r-m
19
What must be the size of the radar beam to provide accurate target reading?
Narrow in the horizontal plane.
20
What is the approximate wavelength of an X-band radar operating on a frequency of approximately 9500MGhz?
3 cm
21
What would be the effect of attenuation in radar performance?
Reduced detection ranges.
22
What should be the range accuracy of a typical radar?
Within 1.5% of the range scale in use
23
When is the transmitted signal of the SART will be most conspicuous on the radar screen?
When the receiver is not fine tuned
24
Which of the following phrases is the correct way of conveying a message?
You have permission to enter the fairway.
25
What is the pulse length of a typical radar?
0.05 to 1.25 microseconds
26
What ratio would be used by a typical ARPA before writing a target into the final switch register?
5 returns 10 pulses
27
What is the typical figure for minimum radar range?
25 meters
28
What is the name of the movable guide line used to measure direction on a radar?
Cursor
29
In calm and clutter free condition, what is the minimum detection range for X-band radar if the target is a 5-meter tall SOLAS ship ( less than 5000 gross tonnage)
8 nm
30
Which of the following has the most effect on the size and shape of a small radar targets?
Pulse length
31
From which of the following does an ARPA builds up the track history of a target?
Series of its range and bearings
32
For all ships/crafts of 500 gross tonnage and upwards but less than 10,000 gross tonnage, what is the radar minimum operational display area in the performance requirements?
250 mm
33
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
34
When using ARPA fitted radars in heavy rain, the following actions should be taken EXCEPT.
Use the 3 cm radar instead of the 10 cm radar.
35
Which of the following is the approximate time a radar pulse travel out to and the echo return from a target at 24 miles?
400 microsec
36
In calm and clutter free conditions, what is the minimum detection range of X-band radar if the target is a 4-meter tall small vessel with radar reflector meeting IMO Performance Standards?
5 nm
37
Which is the MOST correct statement containing the parameters which control the size of radar target echo?
Transmitted power, antenna effective area, transmit and receive losses, RADAR cross section of the target, range to target.
38
You are approaching a sea bouy which emits a racon signal. This signal is triggered by which type of radar?
3 cm
39
An indirect radar echo is caused by the reflection of the main lobe of the radar beams off the observers vessel. Which of the following is NOT a characteristics of an indirect echoes?
They always appear on a bearing of 90 degrees from the true bearing of the contact
40
How would you show your understanding the correct phrase of conveying a message?
Can I use the shallow draft fairway at this time.
41
What should be the typical radar range discrimination?
Not less than 50 meters