1 - NGA

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‘N” or “S” to Indicate whether it is north or south
of the Equator. Aiso called mld-latltude.
mlddhz crrdhtate-Tl?e distance trorn the
mickile poirsl of a chord 10 the middle point 01
lhe mrreaponding circuler arc,
middle point (MP)-Thai point on a circular
wrve which is equidistant from Ihe two ends of
the curve.
mlddletone-in haMtone, any neutral tone
intermediate between the highlights and
shadows of an ori~inaj and the resulting
reproductbn. Ateo, !he tones in a reproduction
between the highlights and Ihe shadows.
mileage chart-A chart showing distances
between various points.
millta~ city map—See city products.
SSZlllti3W geOgmphy—(JCS) The specialized
field oi geography dealing with natural and man.
made physical features Ihal may affecl lhe
planning and COnducl 01 mililary operations,
MIL-HDBK-850
MllltItry grid reterence syslem (MGRS)—
1. The alphanumeric posilion reporting system
used by U.S. Military. 2.(JCS) A syslem which
uses a standard-scaled @d square, based on a
point of origin on e map projection of the Earths
surface In an accurate and consistent manner 10
permit either position referencing or Ihe
~mpu!at~n Of direction and dislance between
gnd positions. See also mllltary grid.
mllltary grid—(JCS) Two sets 01 parallel fines
Interaectisg at right angles and forming squares;
tha grid is superimposed on maps, charts, and
other SImllar representations of lhe Earth%
auriace In an accurate and consistent manner 10
permit Iderrtlficatlon of ground Iocallons with
reapecf 10 other locations and Ihe computation
of diection and distance 10 olher poinls. See
81S0 mllltary grid reference system.
Mliltnry Inetallatlon map (MIM)-D M A
maps constructed rrom one or more standard
series maps and overprinted with information
such as fire zones. training areas and range
Iaciliiles. M [Ms are constructed only for major
camps, posts, and areas which are used
extenaiWly for training and research. Produced
at 1:50,000 acals.
mlllta~ level—A compact ruggedized version
of the dumpy level developed specifically for
163
military use. It k primarily used for thfrd-ordar
levelin~, but has a samnd.order capability.
m)ln.?ry stsndard (h91L.STD)-in
acmrdance with the basic policy of the
Department of Defansa, Defense
Standardization and Spacifi@ion Program,
military standards are issued Ior the
comprehensive presentation of engineering
praclices (including test IrSefhods), procedures,
processes, codes, safety requiremema,
symbols, abbreviations, nomenclatures, type
designations and characteristics Ior siandard
equipmams or items, either singly or In tamifies.
Military standarda ara afso used fo cover overall
characlaristics of famifies o! end hems or major
components. These characteristics Irmlude, as
applicable, envelope dimensions, performance
ratings, primary structural features, and data
required Ior interchangeability of components.
mlllemap-A quantitative disirlbution map on
which there are 1,000 dots, representing the
quanlity depicted; each dol therefore represents
1/1 ,000 of the Iotal, and is located as accurately
as possible accordfW 10 the available evidence.
mllligal—A unit of accalera!bn equal to
1/1 ,000 of a gal, or 1/1 ,000 centimaler per
second per second, Thk unit is usad in gravity
measurements, being approximately onemilliontfl
of the average gravity at fhe Earths
surlace, Such maasuremenf includas the
componant of camrifugal acceleration in the
direction of the gravitational acceleration.
milllgause-Unit 0! magnetic !orca equsl to
0.001 gauss (oersled) or 100 gammas.
mine eurvey-A survey to delannine the
positions and dimensions 01 underground
passages of a mine; also, of the natural and
artificial features (surface and underground)
relaling to the mine. The data include both
horizontal and vertical positiorsa, lengths,
directions, and slopes of tunnels; topographic
and geologic characteristics of the particular
vicinity; ownarshtp ot the land and ot the mine.
mineral survey-A survey made to mark the
iegal boundaries of mineral deposits or orebaaring
formations on the pwbfic domain, whera
the boundaries are 10 be determined by Ilnes
other than the normal subdivision of the pubflc
lands.
Mlnlmelfy Redundant Topology (MINI.
TOPO)—Ttre internal digital spatial data