Acoustics Flashcards
What does SS K stand for?
Submersible ship killer - Hunter killer submarine conventionally powered
What does SSC stand for?
Submersible ship coastal - conventionally powered
What does SSP stand for?
Submersible ship air independent propulsion
What does SSN stand for?
Submersible ship nuclear
What does SSAN stand for?
Submersible ship auxiliary nuclear
What does SSBN stand for?
Submersible ship ballistic missile nuclear
What does SSGN stand for?
Submersible ship guided missile nuclear
Name the advantages/ disadvantages of a nuclear submarine?
They offer advantages of range, speed, and endurance.
The disadvantage is the requirement to constantly be running the nuclear reactor causing noise
Name advantages and disadvantages of a diesel submarine?
Diesel submarine in battery mode is quieter than a nuclear powered submarine
Limited endurance is a disadvantage and submarine has to surface for air known as snorting
There are 7 propulsion modes, names them?
Turbo Reduction Turbo Electric Diesel direct Diesel reduction Diesel Electric Battery drive Air independent propulsion
Name 6 components on the Turbo Reduction engine (nuclear)
Pressuriser Reactor Main coolant pump Steam generator Turbo generator Motor generator Main turbine Electrical propulsion motor Main condenser Battery Reduction gearing
What is the definition of sound?
Sound is defined as a periodic variation of pressure, particle displacement or particle velocity in an elastic medium
How does temperature, depth and salinity effect AV acoustic velocity
1 degree Celsius increase in temperature increased AV by 3m/s
100 m in depth increases AV by 2M/S
1 part per thousand increase in salinity increases AV by 1.1m/s
What does HALT stand for?
High away low towards
Name the three layers of the ocean model?
Mixed Layer
Thermocline
Deep water
What is the definition of ambient noise?
Ambient noise is defined as any noise within the ocean is not target related
What are the two categories of background noise?
Natural noises
Man made noise
Natural noise can be further divided as follows into four categories, what are they?
Biological
Ice
Weather
Seismic
Man made noise can be further divided as follows into what four categories?
Shipping noise
Seismic surveying
Drilling
Active transmissions (military or civilian)
What is the definition of a chokepoint name three examples?
Chokepoints are geographical features, above or below the surface of the sea, they restrict the freedom of movement of a submarine.
The English Channel
The straits of Gibraltar
Greenland-Iceland-UK Gaps
Describe the ocean bottom topography?
Continental shelf - shallows Continental slope - abrupt drop Continental rise - change to angle Ocean trench - deep area Seamounts (jagged or flat top) Abyssal plain - bottom of sea flat Mid-Atlantic ridge
What are the three main requirements of an acoustic detection system?
Good penetration (active) or sensitively (passive)
High resolution
High data rate
Name the elements of an airborne acoustic detection system?
1st Detection
Detection - amplification - demodulation
2nd Processing
Fourier Analysis
3rd Display
Display ADU - Headset audio
A low-fat gram comprises of 3 dimensions and you can process a 4th, what are they?
Time, frequency, and intensity.
Colour (bearing)
What is the definition of Doppler?
Doppler is the apparent change in frequency due to relative motion between a source and a receiver
What does DSCPA stand for?
Doppler shift closest point of approach
What are the six pieces of information that can be gained from a CPA - closest point approach
Speed Range Bearing Track F0 Depth
What is the formulae for calculating speed from CPA
Speed = 1450 x (Fmax-Fmin) divided by F0
F0 = Fmax + Fmin divided by 2
What do the following acronyms stand for? EFR Cyl CFR S/C CSR ERPM R:R SRPM SR BR
Engine firing rate Cylinders Cylinder firing rate Stroke cycle Cylinder shaft rate Engine RPM Reduction ratio Shaft RPM Shaft rate Blade rate
What are the main operating statics for the SSQ-53F DIFAR Size Depth & drop time Battery life Channels
Size A Depth 90ft = 40 seconds 200ft = 65 seconds 400ft = 100 seconds 1000ft = 180 seconds Battery life 0.5, 1, 2, 4, and 8 hours Channels 1-99 except 57, 58 and 93
What does DIFAR stand for? And what is it’s use?
Directional frequency analysis and recording.
They are the primary passive buoy in use in the UK and their allies
The SSQ53G is similar to the SSQ53F, except for what feature?
It’s has a GPS capability
What are the main operating statics for the SSQ-36B Bathy Size Depth & drop time Battery life Channels
Size A
Depth 2625ft and 5ft per second
Battery life 12 minutes
Channels 1-99
What are the main operating statics for the SSQ-62D/E DICASS Size Depth Operating life Channels
Size A
Depth shallow 50ft, 150ft and 300ft
Deep 90ft, 400ft and 1500ft
Operating life 50 ping seconds or 60 mins
Channels
1-99 except 57,58, and 93
A- 6.5khz
B- 7.5khz
C- 8.5khz
D- 9.5khzWhat does DICASS stand for?
And what does it do?
Directional command activated sonobuoy system
The primary active sonobuoy in use they’re able to detect and localise a Submarine
What are the main operating statics for the SSQ-125 MAC Size Depth Battery life Channels
Size A
Depth 65ft, 175ft, 300ft and 500ft
Battery life 8 hours or 140 ping seconds
Channel 96
What does MAC stand for?
Multi static active coherent
