NVSC 401: Exam 2

boost, midcourse, terminal

What are the missile flight phases?

midcourse

What is the longest missile flight phase?

active, semi-active, passive

What are the different types of homing?

command, self-contained, homing

What are the three different guidance types?

5 types: GPS, celestial, inertial, terrestrial, preset

How many types of self-contained guidance methods are there? What are they?

self noise

Is flow noise ambient or self-noise?

temperature, pressure, salinity

What are the three characteristics that affect the speed of sound in water? In order of precedence.

range

Muzzle velocity directly impacts what?

gravity (torpedo falling from aircraft, uses pull of gravity)

impulse (ejector-type, compressed air/gas, gun-type)

reaction (weapon provides its own thrust, rockets/missiles, rail, zero length, canister)

What types of launching systems we have gone over?

Reverb: RL > NL - DI, too much return from the backscatter of transmission

Noise: RL < NL - DI, not enough return due to noise in the environment

What is Reverb Limited Sonar? Noise-Limited Sonar?

5: drag, gravity, Coriolis effect, drift, wind

drag: force that acts opposite to projectile's motion

gravity: forces projectile to fly in parabolic trajectory back towards earth

Coriolis effect: due to the rotation of the earth

drift: due to spinning of projectile (curveball)

wind: no explanation needed for wind

How many exterior ballistics are there? What are they and describe them?

progressive, Ex: cannon

neutral, Ex: rifle

regressive/degressive, Ex: hand gun

What are the different types of propellants and give an example of each?

active sonar

Transducers are associated with what type of sonar?

Sound trends to slower speeds

Where does sound like to travel in terms of SVPs?

speed of sound decreases with depth

What does a negative gradient do to sound?

Direct Path, Half-channel, surface duct, sound channel, convergence zone, bottom bounce

Name 3 propagation paths.

Impact or Contact: senses physical contact, must impact target to detonate

Ambient: senses change in environment

Timer: detonates after preset elapsed time

Command: waits for a signal from control station

Proximity TDD: actuated by some influence of target

What are the different types of fuzes and describe them?

Detonator, Booster, Main Charge

What is the order in a High Explosive (HE) "Train"? In order of highest to lowest sensitivity.

mechanical, chemical, nuclear

What are the three different types of explosions?

blast, fragmentation

List the two types of conventional warheads.

Increasing the number of like-components in PARALLEL will increase the FUNCTIONAL RELIABILITY

How do we increase the functional reliability of our weapons?

Increasing the number of like-components in SERIES will increase SAFETY RELIABILITY

How do we increase safety reliability?

Contact mines

Command detonation

Influence mines

What are the three types of mine triggers?

Magnetic

Acoustic

Pressure

Or Combination

What are the three types of influence mines?

Cable cutting

Detonation by towed sled

Remotely operated robotic vehicles

What are the three current mine-clearing methods?

Air-delivered mines

Surface-delivered mines

Submarine-delivered mines

Asymmetric (civilian)

What are the different delivery methods for mines?

Asset protection

Interdiction

Attrition

Force multiplication

Terrorism

What are the strategies and tactics of mines?

civilians laying mines

What is asymmetric mine warfare?

Laying mines to obstruct shipping and merchants

What is interdiction?

Leave Norfolk, traverse the Atlantic Ocean, sail through the Straight of Gibraltar(STROG), enter the Mediterranean, go through the suez canal, into the red sea, then through the BAM, into the gulf of aden, into the indian ocean, through the straits of malacca into the south china sea, into the philippine sea, into the pacific ocea, through the panama canal, up the caribbean, back into the atlantic to complete the voyage.

Know how to get from Norfolk to Norfolk (circumnavigate the earth), going around the earth on a ship through the water and while hitting main ports.

Confidentiality, Integrity, Availability, Authentication, Non-repudiation

What are the 5 pillars of Cyber Security?

Confidentiality

Protection of information from disclosure to unauthorized individuals, systems, or entities (data-oriented)

Integrity

Protection of information, systems, and services from unauthorized modification or destruction (data-oriented)

Availability

Timely, reliable access to data and information services by authorized users (service-oriented)

Authentication

The ability to verify the identity of an individual or entity (entity-oriented)

Non-repudiation

The ability to correlate, with high certainty, a recorded action with its originating individual or entity (entity-oriented)

C.) Is composed of specific frequencies

Narrow band sonar:

A.) Is used to refine the bearing of a contact

B.) Looks at the entire sound spectrum

C.) Is composed of specific frequencies

D.) Looks at a wide range of the EM Spectrum

A.) Active transmissions from an Ally

Semi-active Homing utilizes:

A.) Active transmissions from an Ally

B.) Its own active transmissions

C.) Sensing the target characteristics (i.e., video, IR)

D.) Its own active transmission AND target characteristics

visual; Ex: scope sighting, wake

infrared detection; Ex: diesel exhaust, IR "wake"

radar; Ex: sail broach, periscope (APS-153 on MH-60R is designed for this)

magnetic anomaly detection; MAD on P-3 Orion is designed for this

What are the four non-acoustic detection threats to a submarine? Give an example of each

Draw.

Be able to draw:

Surface Duct

Convergence zone

Bottom Bounce

Direct Path

Sound Channel

Need > 200 m depth excess

What are the requirements for a convergence zone to exist?

Ambient: Biological, ocean traffic, seismic, hydrodynamic

Self-noise: machinery noise ("hull noise"), flow noise, cavitation

What contributes to ambient noise? self-noise?

Up Doppler: increase in frequency -> decreasing range

Down Doppler: decrease in frequency -> increasing range

Determine a qualitative assessment for frequency based on doppler. (be able to use doppler?)

narrow band

composed of specific frequencies or rangers

broad band, Ex: propellers

wide range of frequencies

direct path Ex: pumps/motors

simplest propagation path, direct contact, close ranges

bottom bounce

propagation path that needs relatively smooth, hard bottom, beam bounces back towards surface, beam directed at rough bottom will not be reflected well

surface duct

propagation path where sound waves are trapped in the isothermal mixed layer near the ocean surface, reflecting off the surface and refracting back upward at the thermocline (google)

positive velocity gradient at the surface - refracts sound back toward surface

half channel

propagation path where cold isothermal water causes positive velocity gradient from surface to bottom

sound channel

propagation path that has the longest range path available, only loss is absorption, and will have a negative over positive gradient

convergence zone

propagation path that requires > 200 m depth excess, sound beam goes so deep that it bends up, and the amount of depth excess determines zone width

In lesson 10, slide 22

Draw and label critical depth

What is beamforming and why is it important?

self-noise

noise generated by own ship

ambient noise

noise generated by environmental and external factors

hydrophone

converts sound to electrical impulse

transducers

converts sound to electrical signal and converts electrical signal to sound

boost phase of flight

phase when weapon receives launch signal to when weapon is in stable flight toward target

midcourse phase of flight

inputs may require to bring missile on course and stay there, longest phase in distance and time

terminal phase of flight

flight phase that has high accuracy and fast response to target's evasive maneuvers

preset

self contained guidance: path is predetermined, prior to weapon launch

Global Positioning System (GPS)

self contained guidance: satellite based navigation system

Celestial

self contained guidance: references position to fixed stars and adjusts

inertial

self contained guidance: senses weapon movement and makes adjustments

terrestrial

self contained guidance: compares actual terrain with predicted flight path and adjusts accordingly

active homing

AMRAAM is ______ homing, transmitter and receiver is on the missile

chemical

Which type of explosion is the most relevant to the US?

detonator ignites booster, booster ignites main charge, main charge detonates, producing destructive power

Explain the High Explosive Train

semi-active homing

SPARROW is _________ homing, has receiver and ally paints target and missile homes in

passive homing

SIDEWINDER is _________ homing, input from outside, using the data solely, no signals in missile

surface duct

Positive over negative gradient SVP results in what?

Active

In some sonar applications, the same transducers are used for both the source and the receiver functions. This would be useful in which type of sonar?

reception/receiving

Hydrophones are designed only for _______________.

radar

Active sonar most closely resembles the operation of what other system we have discussed?

decrease

If a target is moving away from you, what would you expect frequency to do (doppler)?

bearing

frequency, specific

Broadband displays shows ________ vs. time. Narrowband displays show _______________ vs. time. Narrowband is composed of __________ frequencies.

negative, positive

A sound channel is produced when water with a __________ gradient overlays a ________ gradient.

longitudinal

Sound acts like a ____________ wave.

propagation range, propagation speed, resolution

The form of energy to be used in an underwater sensor is to be determined by what three factors?

range, accuracy

Muzzle velocity is desired to be constant for each round in order to determine ______ and _______ of the gun system.

True

(T/F) Muzzle brakes are a method of reducing the force of recoil.