1 - NGA

11/10 peg adjustment—See peg
esfjrxetmsmt.
Eerth fixed coordinate eyeterrt-An y
inordinate system in which the axes are
afatiinary wtih respect to the Earth.
Eatlh Inductor compasa-A compasa
depending for ite Irrdlcatione upon the caurenf
generated In a coil revolving In tha Earfha
rnagnetlc fiefd.
Earth Inductor-An Inslrumenl designed tor
use in magnetic surveys to delermhre magnetic
dip. In principal, lhe instrument is a small
dynamo by which the electrical flow can be
introduced to the cdl of the Instrument. The
presence or abaense of current is indicated by a
ga!vanometer which provides for direct reading
of rnagrratic dip.
Earth Rersourcee Obeervetlon System
Dsta Center (EROS or EDC)-A user
,. .,.. cervices and eaies office established by the US
Department of fnlerior. EDC also processes
LANDSAT data using the EROS Dighal Imaging
Proceaaiw System (EDIPS) and the EROS
Diiital Image Enhancement System (EDIES).
Earth aatelllW-A body thaf orbits about the
Earth; epectficafly, an erlificlal seteltite placed m
Otmf.
Eatih tide-A periodic movement of the
Earth’s crust caused by tide-prcducing forces of
the Moon and Sun.
Earih-centered elltpeold—A referenCe
ellipsold whoee geometric cemer cofncldes wlfh
the Earth’s center of gravity and whose
semimlrwr axis coincides wnh the Earth’s
rotational axis.
easement curve—See eplral curve.
eaet point—See prime verflcal plane.
●eming-1. (grid) Eaefward (that Is left to right)
readlrrg of grid vafues on a map. See elso talee
eaatlng. 2. (plane eurveylng) See
deperture, definition 1.
ebb tld-The porlion of the tide cycla
MIL-HDBK-850
79
E befween high water and the followi~ bw water.
Also celled talllng fldsr.
eccentric anomtrly-See ●nomaly,
definition 3.
stccentrlc error-Cemerirrg error.
eccentric reduction—(trlanguleflon) The
correction which rraJef IM applied to e dlracfion
observed by an instrument with effher the
Instrument or sfgnal (swlrrg), or both, amentric,
to reduce the observed value to what if vmufd
have been ii there had been no eccarrfrldfy.
Also called eccentricity corractlon.
eccentric slgnaf-A signal (target) which is
not in the same veriical line with the station
which if represents.
eccentric etatlon-A survey point over whii
an instrument is cantered and obsenrafkms
made, and which la net in the same vertical tine
with the stal”mn which it represents and to which
fhe observations will be reduced before being
cumbinad with observations al other stations. In
ganeral, an eccentric station is established and
occupied when ff Is impracticable to occupy the
station center, or when If becomes necessary in
order to see points which are not visbie from the
station center.
eccentricity correcflon-ilriangulation) See
sccentric reduction.
eccentricity of alldedeThe distance
between fhe center of figure of the index POlnts
on an alidade and the center of figure of Ihe
graduafed circle. See also eccentricity of
Instrument.
eccentricity of clrcla-The distance between
the center of figure of a graduated circie and ifs
center of rotation. See also eccentricity of
instrument.
eccentricity of elllpsa-The ratio of the
distance between the center and a focus of an
ellipse to the Iengfh of ifs semimajor asis.
eccentric It y of instrument—T h e
combination of emerhriciiy of circle and
eccentricity of al!dade.