Electronic Navigation Flashcards
Which statement concerning the operation of radar in fog is TRUE?
Select one:
a.
Navigation buoys will always show up on a radar.
b.
A sandy beach will show up clearer on radar than a rocky cliff.
c.
Small wooden boats may not show up on radar.
d.
Radar ranges are less accurate in fog.
c.
Small wooden boats may not show up on radar.
The description “RACON” besides an illustration on a chart would mean a __________?
Select one:
a.
radar calibration beacon
b.
circular radio beacon
c.
radar conspicuous beacon
d.
radar transponder beacon
d.
radar transponder beacon
What should you apply to a Fathometer reading to determine the actual depth of water?
Select one:
a.
Add the draft of the vessel.
b.
Subtract the draft of the vessel.
c.
Subtract the sea water correction.
d.
Add the sea water correction.
a.
Add the draft of the vessel.
What does not contribute to the accuracy of a GPS?
Select one:
a.
Position satellite errors
b.
Ship’s speed
c.
Atmospheric variations
d.
Satellite and receiver clock timing errors
b.
Ship’s speed
When using GPS (Global Positioning System) you may expect your position to be accurate within a radius of…
Select one:
a.
20 meters
b.
50 meters
c.
10 meters
d.
100 meters
a.
20 meters
The highest level of navigational accuracy is provided by __________.
Select one:
a.
NAVSAT
b.
DPPS
c.
DSPS
d.
DGPS
d.
DGPS
The modified civilian system that approaches military precision in global positioning is called _________________.
Select one:
a.
PGPS
b.
DGPS
c.
GPS
d.
CGPS
b.
DGPS
Which of the following is NOT a limitation of radar?
Select one:
a.
Radar may be used at night in low visibility conditions.
b.
Mechanical and electrical failures
c.
Radar transmission is line of sight
d.
Minimum and maximum range settings.
a.
Radar may be used at night in low visibility conditions.
Which general statement concerning radar is FALSE?
Select one:
a.
Radar bearings are less accurate than radar ranges.
b.
The ability of radar to detect objects is unaffected by weather conditions, especially dense rain.
c.
Raising the antenna height increases the radar range.
d.
Radar should be checked regularly during clear weather to ensure it is operating properly.
b.
The ability of radar to detect objects is unaffected by weather conditions, especially dense rain.
A fathometer shows the depth from __________________.
Select one:
a.
the waterline to the bottom
b.
the keel to a hard bottom
c.
the bottom of the vessel to the seabed
d.
the waterline to a soft bottom
c.
the bottom of the vessel to the seabed
All modern depth sounders can measure the __________.
Select one:
a.
average depth from the waterline to hard bottom
b.
depth of the water below the location of the transducer
c.
actual depth of the water
d.
average depth of the water to a soft bottom
b.
depth of the water below the location of the transducer
An electronic depth finder operates on the principle that __________.
Select one:
a.
radio signals reflect from a solid surface
b.
pressure increases with depth
c.
sound waves travel at a constant speed through the water
d.
radar signals travel at a constant speed through the water
c.
sound waves travel at a constant speed through the water
You are approaching a RACON it may be identified on the radar by __________.
Select one:
a.
a dashed line running from the center of the scope.
b.
an audible signal when the sweep crosses.
c.
a circle appearing on the scope.
d.
a coded signal appearing on the same bearing at a greater range.
d.
a coded signal appearing on the same bearing at a greater range.
In modern depth indicating equipment the sonic or ultrasonic sound signals are produced electrically by means of a(n)…
Select one:
a.
transmitter
b.
amplifier
c.
transducer
d.
transceiver
c.
transducer
What would give the best radar echo?
Select one:
a.
A 300-foot freighter, bow on.
b.
A 100-foot fishing vessel with a radar reflector in its rigging.
c.
A 300-foot freighter, beam on.
d.
The beam of a three masted sailing vessel with all sail set.
c.
A 300-foot freighter, beam on.
