Ac Flashcards
Classes of submarine
SS (K) SSN SSC SSP SSBN SSAN SSGN
SS (K)
Submersible Ship Killer
SSC
Submersible Ship Coastal
SSN
Submersible Ship Nuclear
SSBN
Submersible Ship Ballistic Nuclear
SSAN
Submersible Ship Auxiliary Nuclear
SSGN
Submersible Ship Guided Nuclear
SSP
Submersible Ship Propulsion (AIP)
Advantages of Nuclear
Range
Speed
Endurance
Disadvantages of nuclear
Constant noise sources
Advantages of diesel
Very quiet on batteries
Disadvantages of diesel
Must snort to recharge batteries
Seven propulsion modes
TR Turbo Reduction TE Turbo Electric DD Diesel Direct DR Diesel Reduction DE Diesel electric BE Battery Drive AIP Air independent propulsion
Snorting system
Page 5 Snort induction mast Engine exhaust into sea Crew compartment ventilation Engine room air intake
Temperature change in velocity
For every 1 degree Celsius increase in temperature per 100 m of water the acoustic velocity will increase by 3 m/s
Warmer is faster
Pressure changes to velocity
As depth increases the pressure grows for every 100 m increase in depth the velocity will increase by 2 m/s
Salinity
For every increase of 1 part per thousand the speed will increase by 1.1 m/s
HALT
High
Away
Low
Towards
Three layer Ocean model
Mixed Layer
Thermocline
Deep layer
Temperature X axis
Depth Y axis
Draw line
Page 8
Ambient noise
Any noise within the ocean that is not target related
Natural noise
Biological
Ice
Weather
Seismic
Man made noise
Shipping noise
Seismic surveying
Drilling
Active transmission
Choke point
Choke points are geographical features, above or below the surface of the sea that restrict the freedom of movement of a submarine.
English Channel
Straits of Gibraltar
Greenland island uk gaps
4 bottoms in order of reflectivity
Sand
Rock
Ooze
Mud and silt
SNELLS LAW
Simply explained as the HALT law rule which states that rays will attempt to retract away from high sound velocity and head towards lower sound velocity
Ocean floor diagram
Shelf Slope Rise Abyssal plain Deep tench Seamounts - guyots and pinnacles Mid Atlantic ridge
4 dimensions of a Lofar gram
Colour (bearing)
Time
Frequency
Intensity
Active sonar vs passive
Active - detects objects by transmitting sound and receiving an echo
Passive - sound received at a sensor produced from a source.
Sound definition
The periodic variation in pressure, particle displacement or particle velocity in an elastic medium
Reasons to surface
Emergency
Comms
Attack solutions
Recharge battery
Frequency
Number of complete waves lengths in a second.
Label Diesel engine
Make
