Mines!

Survivability

1 - susceptibility x vulnerability

P(y)

A lateral range curve depicting the performance of an MCM system against a particular mine threat, that is, the probability of success against a particular mine at abeam (athwartship) distance (y).

Three principal signatures

Acoustic (and/or seismic) Magnetic Pressure

Acoustic backscatter

Acoustic energy reflected back to the sonar receiver by the seas surface, bottom, and particulates in the water column

Clutter

All echos above the set threshold of the detection sonar

How sonar works

An electric impulse from a transmitter is converted into a sound wave by the transducer and propagated into the water. When this wave strikes an object, it is reflected, creating an echo. The returning echo is received by the transducer and converted back into an electric signal. The signal is then amplified, processed in the receiver l, and sent to the display.

Reverberation

Background noise on the sonar display created by bottom roughness and sediment

Bn

Composite probability of prosecution Bn = Pri x Pi x Prn x Pn Reacquisition for identification Identification Reacquisition for neutralization Neutralization Bn = Pn for influence minesweeping

Four phases of mine hunting

Detection Classification Identification Neutralization

Father of MCM tactical theory

Dr. Rufus king reber

mu

Fraction of undetectable mines

MCM tactical philosophy

Hunt when you can, sweep when you must Minehunting performance is not predicated on the internal firing mechanisms of the mine

Exploratory Objective

Intended to confirm the presence or absence of mines within a mine threat area

MDA

Mine danger area Established around a mine location and searched to a relatively high percentage clearance

MTA

Mine threat area

MILCO

Mine-like contact

MILEC

Mine-like echo: a sonar echo determined to be mine-like

NSMWDC

Naval Surface and Mine Warfare Development Center

NOMBO

Non-mine bottom object

P

Percentage clearance achieved by applying an MCM system to the area of interest - for a particular mine threat

PSRR

Progressive sequence reduced risk

J

Runs per track

B value

The characteristic (detection, search, actuation, or cutting) probability within the characteristic width

A value

The characteristic (detection, search, actuation, or cutting) width

Susceptibility

The inability to avoid a man-made hostile environment, such as a mine. Probability of being hit

Vulnerability

The inability to withstand a man-made hostile environment, such as a mine explosion. Probability of being damaged if hit

Mine exploitation

The process of either recovering and reserving safe a mine or acquiring a mine by another means, and exploiting the mine and it's sensors to determine the countermeasures necessary to safely sweep or hunt the mine

SDNE

The standard deviation of navigational error As a platform transits along a track, it wanders about its intended track due to GPS errors, steering inaccuracies, and the continually changing forces of wind, current, and sea. The SDNE is a measure of the ability of an MCM system and it's operating platform to adhere to the intended track through a minefield.

Attrition objective

To continue removing mines as they are added to the mine field so that the danger to transiting ships and MCM platforms is minimal

Reconnaissance objective

To estimate the boundaries of a mines area and to estimate types, settings, and quantities of mines

Breakthrough objective

To minimize the threat to critical ship traffic which must pass through a mine field, in the limited time for MCM operations

D

Track spacing

Basic components of sonar

Transmitter Transducer Receiver Display

Clearing objective

Used to remove or neutralize all mines (or a high percentage of mines) from the assigned area

Environmental factors that affect influence sweeping

Water depth Bottom topography and roughness Bottom composition Underwater and surface obstacles Magnetic minesweeping environment (e.g. electrical conductivity) Acoustic minesweeping environment (e.g. attenuation) Sea state Climate and weather Wind

Environmental factors that effect minehunting

Water depth Water density SVP (sound speed profile; dependent on water temperature, depth, and salinity) Sea state Bottom composition Bottom topography Tidal streams and currents Wind and weather conditions Biologics (such as marine life and sea grass) Bottom clutter Water clarity Optical attenuation

Sonar acronym

sound navigation and ranging