Flashcards in Radar Deck (53)
Can the frequency of radar pulses transmitted per second affect the radar’s maximum range?
Does the Collision Regulations give any preference to ships equipped with radar?
Does the ships trim affect radar minimum range?
Yes, it may introduce obstructions and blind sectors. Only at short distance.
How can the Beam Width Distortion be minimized?
Reduce the setting of the Gain control.
How can the horizontal extent of a “Blind Sector” be accurately determined?
By turning the ship through 360 degrees and determining when a strong echo disappears and reappears on the radar screen..
How does radar antenna height influence on sea clutter?
High antenna height results in more sea clutter displayed on the screen.
How is the amplifier protected from the transmitted pulse?
By the Transmitter/Receiver switch.
IMO resolution 477 applies to all ships built after?
Is it a requirement to have the HM-suppress button spring loaded?
Yes, it is a IMO requirement.
Marine radar bearing accuracy is generally?
Good, but not as good as the range rings.
Marine radar range accuracy is generally?
Good, but the range rings are better than the VRM.
The action taken to avoid collision in reduced visibility should be:
Positive, in ample time and avoiding a series of small alterations.
The actions required by the Collision Regulations can be ignored when:
The radar must be able to operate in relative wind speeds up to?
The reflection of radar pulses is similar to that of?
We have normal transmission of radar waves when the radar horizon is?
10% longer than the visible horizon.
What is known as “Side Lobes” with reference to marine radar?
Unwanted lobes of energy transmitted outside the main radar transmission beam.
What is sometimes known as a Coded Racon?
A racon which displays a Morse code on the radar screen..
What is the correct setting for the “Gain” control?
A little noise (speckled effect) remaining visible on the screen.
What is the correct type of radar display to be selected when at sea?
Always use a compass stabilized display either True Motion or Relative Motion to suit experience and environment.
What is the effect of error in own ships speed, when completing a plot?
Error in the targets course and speed.
What is the effect of gyro error?
All bearings will be wrong.
What is the effect of Sub-refraction?
Distance to the radar horizon is reduced.
What is the fundamental principle of a marine radar?
Detection of other objects outside own ship.
What is the main content of Rule 19 in the Collision Regulations?
The conduct of vessels in restricted visibility.
What is the main disadvantage of true plotting?
Collision risk (CPA) can only be found by completing the plot.
What is the main function of the antenna?
To transmit the radar signals and receive echoes from objects.
What is the main function of the receiver?
Amplify the incoming signals.
What is the main purpose of plotting?
Obtain information about whether danger of collision exists, CPA, TCPA, target course and speed.