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63 Cards in this Set
- Front
- Back
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A sonar transducer can be compared to which
of the following items? 1. Microphone 2. Amplifier 3. Speaker 4. Receiver |
Speaker
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What are the two main factors that affect the
velocity of sound in seawater? |
The temperature and salinity of the water.
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A sound wave traveling from an area of warm
water into an area of cold water will be affected in what way? |
It will bend toward the area of cold water
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Sonobuoys that transmit an acoustic pulse
and detect a resulting echo are classified as what type of sonobuoy? |
Active sonobuoys
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Sonobuoys equipped with an EFS system
have what capability? |
The capability of selecting channel, life and depth settings.
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What information can a DIFAR sonobuoy
provide that a LOFAR sonobuoy cannot? |
Submarine bearing.
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Which of the following sonobuoys provides
water temperature data? |
BT sonobuoys.
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The OTPI system provides what information
to the USW pilot? |
Sonobuoy bearing information with respect to aircraft heading.
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What type of naval aircraft employs the
AN/ASQ-13F dipping sonar system? |
The SH-60F.
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On a dipping sonar system, what component
generates and transmits sound energy into the water? |
The transducer.
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Signal strength lost as sound waves travel
through water is known by what term? |
Transmission loss
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Which of the following sea states causes the
greatest amount of absorption? 1. Whitecap waves 2. Large swells 3. Small swells 4. Calm |
Whitecap waves
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Sound waves in seawater travel how many
times faster than sound waves in air? 1. 8 2. 2 3. 10 4. 4 |
4
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Which of the following sea floor surfaces has
the least amount of signal loss? 1. Rocky 2. Muddy 3. Sandy 4. Smooth and hard |
Smooth and hard
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Multiple reflections of a sound wave is referred
to by what term? 1. Resounding 2. Reverberating 3. Scattering 4. Rumbling |
Reverberating
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Which of the following statements best describes
the effect of divergence on sound waves? 1. The wave spreads out and becomes weaker with distance 2. The beam converges and becomes stronger with distance 3. The beam divides with distance 4. The beam width remains the same with distance |
1. The wave spreads out and becomes weaker
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What is the most important factor affecting the
speed of a sound wave in seawater? 1. Salinity 2. Depth 3. Temperature 4. Frequency |
Temperature
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An increase in the salinity of seawater has what
effect on the sound wave? 1. Speed increases 2. Speed decreases 3. Scattering increases 4. Scattering decreases |
Speed increases
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According to the Doppler effect, when the
source of a sound wave is moving away from the receiver, what apparent change in the sound wave takes place? 1. The intensity increases 2. The wavelength decreases 3. The frequency decreases 4. The frequency increases |
The frequency decreases
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What are the three most common propagation
paths for sound waves? 1. Reflective, refractive, and direct 2. Direct, bottom bounce, and reflective 3. Bottom bounce, surface bounce, and reflective 4. Direct, bottom bounce, and convergence |
Direct, bottom bounce, and convergence
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What is the minimum number of sonobuoys
normally deployed during a USW mission? 1. 1 2. 2 3. 3 4. 4 |
3
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Acoustic data received from a sonobuoy is
transmitted to the sonobuoy receiver using (a) what frequency band, and (b) what type of modulation? 1. (a) VHF (b) FM 2. (a) VHF (b) AM 3. (a) UHF (b) FM 4. (a) HF (b) AM |
1. (a) VHF (b) FM
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Sonobuoys that transmit an acoustic pulse and
detect a resulting echo are classified as what type of sonobuoy? 1. Passive 2. Active 3. Ringing 4. Delay |
2. Active
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What are the three methods of deploying a
sonobuoy? 1. Pneumatic, free-fall, and cartridge 2. Pneumatic, free-fall, and hydraulic 3. Free-fall, hydraulic, and piston 4. Cartridge, hydraulic, and piston |
1. Pneumatic, free-fall, and cartridge
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Sonobuoy descent-retarding devices are necessary
for what reason? 1. To prevent ice build-up 2. To allow electronic circuits to activate 3. To reduce water entry shock 4. To allow visual tracking |
3. To reduce water entry shock
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How are sonobuoys activated?
1. Atmospheric pressure switch during descent 2. Saltwater battery activation 3. Command signal from the operator 4. Preset timer |
2. Saltwater battery activation
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What happens to the sonobuoy after the battery
dies? 1. It sinks to the bottom 2. A recovery pinger activates 3. A recovery float deploys 4. It remains in place and decomposes |
1. It sinks to the bottom
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Sonobuoys equipped with an EFS system have
what capability? 1. Unlimited battery life 2. Electromagnetic pulse protection 3. Frequency discrimination 4. Selectable channel, life and depth settings |
4. Selectable channel, life and depth settings
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A LOFAR sonobuoy uses what type of
hydrophone? 1. Unidirectional 2. Omnidirectional 3. Hybrid 4. Reactive |
2. Omnidirectional
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Under most situations, what type of sonobuoy
is best for initial detection? 1. DIFAR 2. LOFAR 3. VLAD 4. DICASS |
2. LOFAR
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What information can a DIFAR sonobuoy
provide that a LOFAR sonobuoy cannot? 1. Submarine bearing 2. Submarine depth 3. Submarine size 4. Water temperature |
1. Submarine bearing
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Which of the following sonobuoys is designed
for long-range submarine detection in deep water? 1. LOFAR 2. DIFAR 3. VLAD 4. DICASS |
3. VLAD
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DICASS sonobuoys operate on the same
principle as what other electronic system? 1. INS 2. IFF 3. TACAN 4. Radar |
3. TACAN
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DICASS sonobuoys are commanded to ping by
what source? 1. A UHF signal from the USW aircraft 2. A VHF signal from a surface ship 3. Apreset timer located within the sonobuoy 4. A range proximity switch located within the sonobuoy |
1. A UHF signal from the USW aircraft
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An EER sonobuoy is typically used in conjunction
with what other sonobuoy for long-range detection? 1. DICASS 2. VLAD 3. LOFAR 4. DIFAR |
2. VLAD
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What are the two special-purpose sonobuoys?
1. BT and DIFAR 2. BT and DLC 3. DLC and DIFAR 4. DLC and LOFAR |
2. BT and DLC
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What information does a BT sonobuoy provide?
1. Salinity 2. Pressure versus depth 3. Water temperature at sea surface 4. Water temperature versus depth |
4. Water temperature versus depth
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The ARR-78 sonobuoy receiver is capable of
simultaneous reception of up to what number of sonobuoys? 1. 5 2. 10 3. 20 4. 99 |
3. 20
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The ARR 84 sonobuoy receiver is used in the
SH-60 series helicopter for what reason? 1. Accommodation of weight restrictions 2. Rotor nulling circuitry 3. Higher signal to noise ratio 4. Less sonobuoy monitoring requirements |
1. Accommodation of weight restrictions
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What component of the sonobuoy-based sonar
system extracts acoustic target information from both active and passive sonobuoys? 1. Sonobuoy receiver 2. Power supply 3. Data display 4. Spectrum analyzer |
4. Spectrum analyzer
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The OTPI system works in conjunction with
what other aircraft system? 1. DF 2. VOR 3. TACAN 4. ACLS |
1. DF
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The OTPI system provides what information to
the USW pilot? 1. Distance to the sonobuoy 2. Sonobuoy bearing with respect to true north 3. Sonobuoy bearing with respect to aircraft heading 4. Sonobuoy depth |
3. Sonobuoy bearing with respect to aircraft
heading |
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Dipping sonar systems use what type of sonar
detection? 1. Active only 2. Passive only 3. Active and passive 4. Active and array |
3. Active and passive
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What distinct advantage does a dipping sonar
have over a sonobuoy based system? 1. Low operating cost 2. Operator control of the search depth 3. Longer operating time 4. Search area increased |
2. Operator control of the search depth
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In addition to active and passive sonar modes, a
dipping sonar provides what other information? 1. Water salinity and temperature 2. Water pressure salinity 3. Communications and water temperature 4. Communications and water pressure |
3. Communications and water temperature
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The electrical interface between the sonar set
units mounted in the helicopter and the submerged sonar transducer is provided by what component of the ASQ-13F dipping sonar set? 1. Power supply 2. Multiplexer 3. Dome control 4. Sonar data computer |
2. Multiplexer
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What unit of the ASQ-13F converts sound
energy to electrical signals? 1. Receiver 2. Computer 3. Transceiver 4. Transducer |
4. Transducer
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A submerged sonar transducer is used to
transmit and receive voice signals to and from other USW helicopters, submarines, or similarly equipped surface ships during what ASQ-13F mode of operation? 1. BT 2. UVC 3. Active 4. Passive |
2. UVC
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What information can a DIFAR sonobuoy
provide that a LOFAR sonobuoy cannot? 1. Submarine bearing 2. Submarine depth 3. Submarine size 4. Water temperature |
1. Submarine bearing
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Which of the following sonobuoys is designed
for long-range submarine detection in deep water? 1. LOFAR 2. DIFAR 3. VLAD 4. DICASS |
3. VLAD
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DICASS sonobuoys operate on the same
principle as what other electronic system? 1. INS 2. IFF 3. TACAN 4. Radar |
3. TACAN
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DICASS sonobuoys are commanded to ping by
what source? 1. A UHF signal from the USW aircraft 2. A VHF signal from a surface ship 3. Apreset timer located within the sonobuoy 4. A range proximity switch located within the sonobuoy |
1. A UHF signal from the USW aircraft
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An EER sonobuoy is typically used in conjunction
with what other sonobuoy for long-range detection? 1. DICASS 2. VLAD 3. LOFAR 4. DIFAR |
2. VLAD
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What are the two special-purpose sonobuoys?
1. BT and DIFAR 2. BT and DLC 3. DLC and DIFAR 4. DLC and LOFAR |
2. BT and DLC
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What information does a BT sonobuoy provide?
1. Salinity 2. Pressure versus depth 3. Water temperature at sea surface 4. Water temperature versus depth |
4. Water temperature versus depth
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The ARR-78 sonobuoy receiver is capable of
simultaneous reception of up to what number of sonobuoys? 1. 5 2. 10 3. 20 4. 99 |
3. 20
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The ARR 84 sonobuoy receiver is used in the
SH-60 series helicopter for what reason? 1. Accommodation of weight restrictions 2. Rotor nulling circuitry 3. Higher signal to noise ratio 4. Less sonobuoy monitoring requirements |
1. Accommodation of weight restrictions
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What component of the sonobuoy-based sonar
system extracts acoustic target information from both active and passive sonobuoys? 1. Sonobuoy receiver 2. Power supply 3. Data display 4. Spectrum analyzer |
4. Spectrum analyzer
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The OTPI system works in conjunction with
what other aircraft system? 1. DF 2. VOR 3. TACAN 4. ACLS |
1. DF
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The OTPI system provides what information to
the USW pilot? 1. Distance to the sonobuoy 2. Sonobuoy bearing with respect to true north 3. Sonobuoy bearing with respect to aircraft heading 4. Sonobuoy depth |
3. Sonobuoy bearing with respect to aircraft
heading |
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Dipping sonar systems use what type of sonar
detection? 1. Active only 2. Passive only 3. Active and passive 4. Active and array |
3. Active and passive
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What distinct advantage does a dipping sonar
have over a sonobuoy based system? 1. Low operating cost 2. Operator control of the search depth 3. Longer operating time 4. Search area increased |
2. Operator control of the search depth
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In addition to active and passive sonar modes, a
dipping sonar provides what other information? 1. Water salinity and temperature 2. Water pressure salinity 3. Communications and water temperature 4. Communications and water pressure |
3. Communications and water temperature
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