1 - NGA

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MAD Operrstlonal Effecflveness Charm
@fOE)-Deiailed information on geomagnetic
fiald Intensftlea In ocean areas, Used in plannlng
tactical AntiSubmarine Watfare (ASW)
oparallons. Magnetic anomalies are color coded
to assist in setting sensitivity on Magnatic
Anomafy Detaction (MAD) equipment.
MAD Plannlrrg Charta (MADPC)—
Intormatlon on geomagnetic total-field
Intenaffkrs for selacfed ccean areas. Used as a
planning base for An!lSubmerine Warfare
(ASW) op’atlons. Magnetic anomaliea are color
coded to assist in datermlning the effectiveness
of Magnetic Anomaly Detection (MAD)
equipment for a given erea,
magazine—(aerial camera) A component in
the aerial camera sysfem. If serves to ho!d the
exposed and unexposed film and includes the
film drive mechanism and film tlanenlng device
(platen).
magenta contact scmcm—A contact film
screen composed of msgema dyed dots 01
variable density used for making hafflone
negatives.
msgnatic amplltude-Amplilude relative to
magnetic .eaat or west. Sea also amplitude.
msgnetlc annual change—The amounf of
magnetic secular change undergone in 1 year.
Also caflad annual change; annusl
mEgnetlc change; annuel rate; annuaf
rate of change. See also mag netlc
sacular change.
MagnOtlC annual varlatlon—The small
regufar fluctuation in the Earth’s magnetism,
havfng a perbd of 1 year.
. .
magnsmc varlatlon.
Also called annual
mrrgnatlc anomaly-See local magneilc
anomaly.
magnatlc azimuth—At the point of
obsewafion, the angle between the vertical
ptene through the observed objecf and the
vertical plane In which a traely suapanded,
SymfnStfiCally magnetized needle, influenced by
no tranSleM arltficisl magnetic disturbance, will
come 10 rest. Magnalic azimuth is generally
MI L-H DBK-850
151
M
reckoned from megnalw ncrlh (O”) clockwise
through 360”, Such an azinufh shoufd be
marked as being magnetic, and the date of ifs
appfiiability should be given. Magnetk ezlrrwfhs
are frequently measured wffh two Wlfd T-O
Iheodolites in rxmnactiin with compass rose
surveys.
magnetic bearing-l. (navigation) Bearing
relative 10 magnetic north: mmpaaa bearing
correcfed for deviafbn. 2. (swwaylrsg) Bearing
relative 10 magnefic north or south, and staled
in an east or weat dtrectbn. The compasses
included with the engineer transit and the 1minute
theodolite can be used fo read magnetic
bearings. Also called compass baarlng.
magnetic chart-A speciaf purpose map
depicting the dislributbn of one ot the magnalic
elements, as by bogonlc lines, or of fts secular
change.
magnetic compasa—A compass depending
upon the anraction of Ihe magnelism of the
Earth for its directive tome.
msgnetlc dally veriaUon-The transient
change in the Earth% magnetic Iiekd associated
with the apparenf daily motions of the Sun and
Moon. In most places the solar dally variation
follows approximately a consisfenf pattern,
affbough with appreciable and unprediiabfe
changes in form and amplitude.
magnatlc declination-(JCS) The angle
between fhe magnetic arnj geograpfskef
meridians at any place, axpressed in degrees
east or west to indicate Ihe dlrectbn OJmagnetic
noflh from true nonh. In naufkal and
aeronautkal navlgaflon the term msgnetlc
variation Is used instead of magnatlc
decllnaflon, and Ihe angfe is termed
varlatlon 01 the compass or megnetlc
varlatlon. Magnetic decfinatlon Is not
otherwise synonymous with magnetic variation,
which refars to regular or irmgufar change with
lime of the magnefic declination, dip, or
intensify. [Because of bcal attraction, Ihe
magnetic declination of two close fXJnt6 may
differ by severaf degrees.] See also Magnetic
varlatlon.
Imagnetfc
devlatlon—See Oevlatlon.