Term
|
Definition
- Deny submarine capabilities
- Safe shipping route
- Protect land targets & assets
- Locate - Track - Prosecute |
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Term
| Aim of Tactical Oceanography |
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Definition
- Determine Unit Size / Disposition & Speed / Route
- Detect friendly submarines
- Emission Control Policy
- Develop Tactics
- Discover vulnerabilities |
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Term
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Definition
- Current Speed
- Wave Height |
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Term
| What are the Oceanography aspects? |
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Definition
- Physical Characteristics
- Chemical Composition
- Geological Composition
- Marine Biology |
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Term
| Aim of Oceanology (Naval Interests) |
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Definition
- Composition of the ocean
- Factors that change or influence the ocean composition
- Effects of the ocean in sound propogation |
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Term
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Definition
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Term
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Definition
-Dissolved solids and gases
- Material in suspension
- Acidity |
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Term
|
Definition
- Ocean floor landscape and composition
- All bottom composition
- Relief features |
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Term
| Define the Afternoon Effect |
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Definition
| Solar heating produces a transient negative thermocline at the surface. It is so named because the maximum effect normally occurs during the afternoon, though it may occur at other times of the day. It results in the refraction of acoustic energy away from the surface and may therefore degrade hull mounted sonar(HMS) performances. - Upper 200 ft. - |
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Term
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Definition
- Plant life
- Animal life
- Effects of habitat on life
- Sedimentation
- Physical and chemical changes in environment
- Other factors that affect or disturb marine organisms |
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Term
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Definition
- Production
- Transmission
- Effects on the environment |
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Term
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Definition
PCGBMO
Physical
Chemical
Geological
Biological
Meteorological
Ocean Acoustics |
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Term
| Primary Concerns of Military Oceanography |
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Definition
Determining means of utilizing ocean in means of offence or defence.
- Ocean Acoustics
- Physical Oceanography
- Geological Oceanography |
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Term
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Definition
- Near shore (coastal)
- Most difficult and complicated conditions to analyze
- Complicated landscape (Ocean floor, and structures) |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
- Transverse
- Longitudinal
- Torsional |
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Term
| What type of vibrational frequencies are found on the ocean surface? |
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Definition
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Term
|
Definition
| Motion of particles is perpendicular to the direction of the wave. ~~~~~~~ |
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Term
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Definition
| Travel in the same direction. (Slinky going horizontal) ==== |
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Term
|
Definition
| Moves around the length of an object (Unbalanced washing machine) |
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Term
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Definition
| Leading edge of a wave at which point maximum compression is occurring at a given moment. |
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Term
| Describe Sound Production |
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Definition
| Source -> Medium -> Detection |
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Term
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Definition
| A line that is drawn 90° to a wave front |
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Term
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Definition
| Any element that vibrates (energy) |
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Term
|
Definition
| Any medium that has elastic qualities |
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Term
|
Definition
Object receives wave
Absorbs only part of the wave |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
Temperature change
A region where a significant gradient of temperature exists. There exists Permanent, Seasonal and Transient thermoclines. |
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Term
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Definition
| Vertical movement of water caused by changes in density due to temperature and salinity. |
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Term
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Definition
| Depth at which sound can reach maximum speed in upper mix layer. (~300 ft.) or meters, idk. |
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Term
|
Definition
Area at which pressure and temperature drop (~1000 ft.)
A negative temperature gradient which forms below the surface mixed layer and/or seasonal thermocline. The gradient within the thermocline is appreciably greater than the temperature gradient below it. as indicated in the name it is a permanent ocean feature which is deepest near the equator and rises as latitude increases. |
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Term
|
Definition
- "Drop-off"
- Pressure is most dominant factor here |
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Term
|
Definition
- Wind
- Convection
- Advection
- Upwellings
- Downwellings |
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Term
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Definition
| - Waves - Wind Strength - Wind duration - Current mix layer depth - Water density below mix layer |
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Term
|
Definition
- Increased in density of surface water resulting in overturn of water mass. - # heat loss to atmosphere - Ignition mix layer depth - Water density below layer
https://www.youtube.com/watch?v=xaa9h_GAflg |
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Term
|
Definition
| The process of transfer of air and water by predominantly horizontal movement. |
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Term
|
Definition
- Cold water to Top
- Driven by wind and Coriolis Effect |
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Term
|
Definition
| - Hot water to Bottom - Coriolis Effect |
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Term
| Oceans comprise what % of the water on the planet |
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Definition
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Term
| Ice Caps and Glaciers comprise what % of the water on the planet? |
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Definition
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Term
| Effects of Bottom Composition |
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Definition
- Reflection
- Absorption
- Scattering (Reflecting)
- Attenuation (Combination of absorption and scattering)
- Reverb |
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Term
| Dominant water masses in Pacific |
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Definition
| Alaskan Gyre Kuroshio Current California Current Ross Sea |
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Term
| Dominant water masses in Atlantic |
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Definition
(ALL WARM CURRENTS)
Sargasso Sea
Golf Stream
Labrador Sea
Cold Shelf
Slope Waters |
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Term
| What are Transition Waters? |
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Definition
| Area where dominant water masses meet from Pacific to Atlantic (Hot to Cold) vice versa |
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Term
|
Definition
Boundaries between adjacent water masses that have different physical characteristics.
- Found in all oceans
- Vary in size and density |
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Term
|
Definition
- Surface winds
- Earth's rotation
- Differences in water density |
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Term
|
Definition
| A circular movement of water formed along the edge of a permanent current, between two adjacent currents flowing counter to each other, and when currents or tidal streams flow past obstructions. |
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Term
| Internal Waves happen where? |
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Definition
| Between layers of water masses. |
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Term
|
Definition
| Total amount of solid materials in grams dissolved in one Kg of seawater. Expressed in parts per thousand ‰ |
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Term
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Definition
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Term
| Effect of the Horizontal Profile (TEST) |
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Definition
| Contributes to sonar bearing errors in long range sensors. (Whatever that means.) |
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Term
| What is a major influence of horizontal profile |
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Definition
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Term
| What is Refraction (TEST) |
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Definition
| Bending of a sound wave. *BONUS : Sound rays will refract towards lower resistance* |
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Term
|
Definition
Sound waves take the path of least resistance. Sound is Lazy.
Sound rays will refract towards lower resistance. (Upper mix layer) |
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Term
|
Definition
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Term
|
Definition
Positive \
Negative /
Isometric | |
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Term
| Types of Sound Paths (TEST) |
|
Definition
5 Basic Sound Paths
2 Sound Channels
Paths :
- Direct Paths
- Bottom Bounce
- Half Channel Sound Propagation
- Multipath Sound Propagation
- Convergence Zone
Chanel:
- Surface Sound Chanel (Ducting)
- Subsurface Sound Channel |
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Term
|
Definition
| Sonic Layer Depth : The depth near the surface of maximum sound velocity. |
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Term
|
Definition
| The sound ray that becomes horizontal at SLD |
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Term
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Definition
| A zone in which little sound from a particular source can penetrate, usually as a result of refraction of the sound rays. |
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Term
| Conjugate Depth required for 50% POD (Probability of Detection) |
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Definition
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Term
| Conjugate depth required for 80% POD (Probability of Detection) |
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Definition
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Term
| Subsurface Sound Channel (TEST) |
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Definition
Negative SV gradient overlies a positive SV gradient below. (Can't read my notes.) TO CLARIFY
Usually a horizontal layer within the ocean, where the sound speed at the layer boundaries is greater than that within the layer. this results in refraction which continues a portion of the transmitted energy within the layer. in a sound channel, propagation loss is less, due to the absence of reflection loss and the reduction of spreading. |
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Term
| Types of Subsurface Sound Channels |
|
Definition
Shallow Sea Channel (Tactical)
Deep Sea Channel (SOFAR) whatever that stands for) |
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Term
|
Definition
(Tactical)
- Found in permanent thermocline.
- Associated with fronts and eddies |
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Term
|
Definition
(CZ)
Upper boundary is formed at SLD
Form positive SV gradient due to pressure (Deep sea)
Minimum 400m depth excess
Lower boundary is formed at the SV below channel axis |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
(FOM) TL = (SL - NL + DI - DT + TS) / 2
DIVIDED BY 2(Active Sonar, comes back) |
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Term
|
Definition
| (FOM) TL = SL - NL + DI - DT |
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Term
|
Definition
| (FOM) Max allowable transmission loss between the source and receiver that will still give an average operator a 50% POD (Probability of Detection) |
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Term
|
Definition
Source Level
Loudness (intensity) in dB's |
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Term
|
Definition
| Sonar Performance Figures |
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Term
|
Definition
Noise Level
All noise (ambient and self noise) |
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Term
|
Definition
| Total noise after we eliminate every frequency recognizable. |
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Term
| What is the dominant noise in the ocean? |
|
Definition
Long distance shipping noise
Lower frequencies 60Hz spectrum |
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Term
| What is considered Heavy Shipping |
|
Definition
| 4+ cargo ships or tankers (big ships) closer than 30nm (nautical miles) |
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Term
|
Definition
The ability of a sensor to narrow its sensitivity arc therefore increasing the signal/noise ratio.
WOW. |
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Term
|
Definition
| Directivity Index Rule : Every time directivity of a sensor is halved DI increases by 3dB. |
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Term
|
Definition
| (DT) Amount of signal over background noise that is required for an average operator to have a 50% POD (Probability of Detection) |
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Term
|
Definition
(TS) Measurement of reflectivity of a target when exposed to active sonar transmission.
Depends on:
- Target size
- Target Shape
- Roughness (surface of target)
- Type of construction
- Target Aspect (Whatever that means) |
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Term
|
Definition
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Term
|
Definition
Decrease of sound intensity with range resulting in combined effect of :
- Spreading loss
- Absorption
- Scattering
- Refraction (Reflection) |
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Term
| How long is the towed array? |
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
| Why is Pre-Sail Planning important? |
|
Definition
| Reduce possibility of Marine Mammal (MM) encounters and casualties. |
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Term
| How long must the waters be monitored for before performing activities? (Marine Mammals, MM) |
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Definition
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Term
| What steps do we take to mitigate MM activity? |
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Definition
Ramp-up Procedures (Get the fuck out of here)
Monitor Ocean 30 mins. prior to activities |
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Term
| Order the best ways of spotting MM |
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Definition
1) Visual
2) UWT (below 2 knots) Underwater Telephone
3) Passive Sonobuoys
4) CANTASS
5) HMS Passive |
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Term
|
Definition
| The law which governs the angle relationship between an incident ray and a refracted ray as a result of a change in wave speed |
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Term
|
Definition
| An effect resulting from the Earth's rotation that causes particles in motion to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. |
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Term
|
Definition
| A layer bounded by the sea surface and the Sonic Layer Depth (SLD) |
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Term
|
Definition
| Usually a horizontal layer within the ocean, where the sound speed at the layer boundaries is greater than that within the layer. This results in refraction, which confines a portion of the transmitted energy within the layer. in a sound channel, propagation loss is less due to the absence of reflection loss and the reduction of spreading loss (cylindrical instead of spherical) |
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Term
| Name the 3 type of vibrations |
|
Definition
- Transverse
- Horizontal
- Torsional |
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Term
| What are the 5 effects of bottom composition |
|
Definition
- Reflection
- Absorption
- Scattering
- Attenuation
- Reverb |
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Term
| What are the requirements for afternoon effect to occur? |
|
Definition
- Strong Solar Heating
- Little or No Wind
- Little or No Cloud |
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Term
| What are the three types of sound velocity Gradient |
|
Definition
- Positive \
- Negative /
- Isometric | |
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Term
| What are the five basic sound paths that can exist in the ocean? |
|
Definition
- Direct Path
- Bottom Bounce (BB)
- Half Channel Sound Path
- Multi-Path
- Convergence Zone |
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Term
|
Definition
| Sound rays travel from source to receiver by more than one sound path. ex : BB and DP |
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Term
| What is the general rule for Annulus width? |
|
Definition
| CZ annulus is 10% of its range |
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Term
|
Definition
| The residual acoustic background noise in the se after identifiable sources have been eliminated. It is produced by distant shipping, marine life, precipitation, sea state, distant storms, seismic activity, ice movement, turbulence, currents, industrial activity and thermal motion. It does not include self noise. |
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Term
| What are the 5 main processes involved in heat redistribution |
|
Definition
- Upwellings
- Downwellings
- Convection
- Advection
- Wind Mixing |
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Term
| What are the 3 types of sound |
|
Definition
- Subsonic
- Sonic
- Ultrasonic |
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Term
| Name the 3 layers of ocean model |
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Definition
| - Mix Layer - Permanent Thermocline - Deep Ocean |
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Term
|
Definition
| A region where a significant gradient of temperature exists. There exists Permanent, Seasonal and Transient thermocline. |
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Term
|
Definition
| The production of light by living organisms and bacteria within the sea; it is normally induced by mechanical stimuli such as the passage of ships or submarines. |
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Term
| What are the 3 factors affecting SV profiles? |
|
Definition
- Temperature
- Density
- Salinity |
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Term
|
Definition
| The difference between critical depth and bottom depth, i.e., the amount of water below the bottom of the deep sound channel. A depth excess of at least 400m is required for good CZ propagation. |
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Term
|
Definition
| A periodic variation in pressure, particle displacement, and particle velocity in an elastic medium. |
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Term
| The sum total of all noise present in the ocean at any given time after all identifiable noise has been removed is? |
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Definition
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|
Term
| Area where little or no sound energy will enter? |
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Definition
|
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Term
| What are the factors Affecting SV profiles? |
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Definition
| - Temperature - Density - Salinity |
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Term
| The rising of colder bottom water towards the surface driven by surface winds and corilois effect is : |
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Definition
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Term
| Name 2 of the conditions for CZ |
|
Definition
- Must be a Negative SV gradient below SLD
- Water column deep enough to form positive SV gradient due to pressure.
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|
Term
| When the sound rays travel directly from source to receiver, which sound path is it? |
|
Definition
|
|
Term
|
Definition
| The number of waves passing by a given point in a particular unit of time. It is usually defined by the number per second, for which the unit is Hertz (Hz), previously defined as cycles per second. |
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Term
|
Definition
| The depth near the surface of maximum sound velocity. |
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Term
| The depth at which the mixing ceases to occur is referred to as : |
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Definition
|
|
Term
| The number of cycles completed in a unit of time is : |
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Definition
|
|
Term
| A region in water column where sound speed first decreases with depth to a minimum value, then increases is referred to as : |
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Definition
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|
Term
| The ........... Is a permanent feature of the deep ocean. The upper boundary of the deep ocean. The upper boundary of the DSC is formed at the SLD, where decrease in sound speed begins to produce a negative sound speed gradient. |
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Definition
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Term
| It can be defined as the intensity of the signal of interest reported as though it had been measured at a standard distance from the signal generator. The distance is usually one yard or one meter and reported in decibels is : |
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Definition
|
|
Term
| It's the interface between 2 different water masses : |
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Definition
|
|
Term
| The multiples of the fundamental frequency is : |
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Definition
|
|
Term
| The level of signal or noise measured over a particular frequency band is : |
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Definition
|
|
Term
|
Definition
Rotation : Clockwise
Diameter : 100-200nm
Depth : 300-500m
Speed : 5km / day
Life Span : 6 mo. |
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Term
|
Definition
Rotation : Counter-Clockwise
Diameter :
Depth :
Speed :
Life Span : 1-4 years |
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|
Term
| General rule for Annulus Width is : CZ annulus is ...% of its range. |
|
Definition
|
|
Term
Give the relationship between SV and Temperature
An Increase of 1 degree |
|
Definition
|
|
Term
Give the relationship between SV and Salinity
An Increase of 1%o Salinity |
|
Definition
|
|
Term
Give the relationship between SV and Depth
An Increase of 100m |
|
Definition
|
|
Term
The depth of mixed layer depends on :
|
|
Definition
Wind Strength
The density gradient below the mixed layer
The MLD
Duration of wind |
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Term
| The portion of the water column from the base of the permanent thermocline or pycnocline to the ocean floor. Water temperature are relatively uniform throughout is : |
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Definition
|
|
Term
| What is the combination of ambient noise and self noise received at the sensor? |
|
Definition
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|
Term
| Can extend to about 300m in mid-latitudes. Subject to mixing by waves and thermohaline circulation. |
|
Definition
|
|
Term
| Below SLD, form positive SV gradient due to pressure, minimum 400m depth excess, are 3 of many conditions for what? |
|
Definition
|
|
Term
| The horizontal movement of water due to ocean currents. Can also be generated by surface currents known as wind drift currents is? |
|
Definition
|
|
Term
|
Definition
| The total noise that is produced by a sonar platform or the equipment within it. |
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Term
| Occurs when a positive gradient exists above SLD |
|
Definition
|
|
Term
| Sound rays travel from source to receiver by more than one sound path |
|
Definition
|
|
Term
| Reflection, Absorption, Scattering, Attenuation, Reverberation are : |
|
Definition
| The effects of bottom composition |
|
|
Term
| The 2 phases in a sound wave |
|
Definition
- Compression ^
- Rarefaction V |
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|
Term
| A Surface Sound Channel occurs when : |
|
Definition
| A positive gradient exists above SLD |
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Term
| Dominant Pacific Water Masses |
|
Definition
Alaskan Gyre,
Kuroshio Current
California Current
Ross Sea |
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Term
| What are the three methods of obtaining a SPF while at sea? |
|
Definition
XSV Probe
XBT probe using the MK-8F bath recorder set to XSV (Laptop)
Databases (ARP) |
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Term
| What characteristics can cause modifications to the thermal structure of a water mass? |
|
Definition
- Season
- Latitude
- Ocean Currents |
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