1 - NGA

Ilthograpfrlc copy—A graphic reproduced
by the lithographic precess. Also called
Iltho COpy.
Ilthographlc drafting—See Iuschlng.
lithography—A planographlc method of
printing based on the chemical repulsion
between grease and waler to separate the
printing from rronprinting areas. See also
offset Illhogrephy;
photolithography.
lithosphere-The solid part of lhe Earth or
other spSflal body. Distinguished from the
efmosphera and the hydrosphere.
local adjustment—See station
ad]uatmen!.
local apparent tlma—The apparant solar
time for fhe meridian of the observer.
local sefronomlc tlma—Mean time
reckoned from the upper branch of the
bcal maridian.
Iocel attraction—See local magnetic
anomaly.
Iocsl chart-A large-scale aeronautical charf’
designed tor contact fiighl in a congested
area.
local clvll time—See local mean time.
local coordinate system—A right-handed
rectangular coordinate system of which the
z-esis coincides with the plumb fine through
the origin
local datum—The point of reference of lhe
oeodetic control used exclusively in a small
iirea. Usually iden(ifiad by a pro-per name.
local horlzcm—See epparenl horizon.
local trour angle-Anguler distance wesl 01
the bcal celestial meridian; the arc of Ihe
celestial equator, or the angla at the
celestial POle, belween the upper branch 01
the local celestial meridian and Ihe hour
circle of a point on the celeslial sphere,
measured westward from Ihe local celestial
meridian through 360”.
MIL-HDBK-850
145
local lunar time-The arc oj the celeslla)
squalor, or the angla at Ihe celasiial pie,
between the bwer branch of the kx.al
calestial meridian and lhe hour clrcfe of the
Moon, measured westward from the lower
branch of the bcal csfestlal mertcfian
through 24 hours; focal hour arrgla 0! the
Moon, exprasaad in lime unffs, PIUS 12
hours. See also Greenwich lunar time.
IOIX31 magnatlc anomaly-Abnormal or
irregular variation of the Earth’a rnegnafii
field extemfing over a ralalivaly small araa,
due to local magnetk inlluencas. Also
called anomaloua megnetlc varlatlon;
local attraction; local magnatlc
disturbance; magnetic anomaly.
local mean time-l. (JCS) The time
interval elapsed since tha mean WI%
transit of the observets amemaridian. 2.
The arc of the celestial equator, or the
angle at the celestial pole, between the
lower branch of the local celestial meridian
and fhe hour circle of the mean sun,
maasured westward from the lower branch
of the bcal celestial meridian through 24
hours: local hour angle of fhe mean sun,
expressed in time units, plus 12 hours.
Called local cIvII tlmo in United stales
terminology irom 1925 through 1952. See
also local aawonomlc time:
Universal Time.
local merldlan-The meridian through any
particular place or observer, serving as the
reference for local time. Also called
reference meridian.
Iocel eldereal time-The local hour arwle
of the vernal equinox, expressed in time
units. Locel stiareaf lime at the Greerrwich
maridlan is called Greenwich aldereal
time.
local tlma-1. Time based upon the local
meridian as reference, as contrasted with
that based upon a time zona mesidlan, or
the meridian of Greenwich. 2. Any time
kept locally.
local vertbal—The direction of the
acceleration of gravity, aa opposed to tha
normal 10 a reference eurlace.
Iocatlon survey-The establishment on the
ground of points and fines in positions