1 - NGA

1
MI L-HDBK-850
g80d0dc fine-A tine of SfWfSd d-nctt
bafween my fvm pdnta en any !nafhenmticelFy
dafinad surface. Agaodadclkmfcfan aU@ecid,
in ganerat, h a Ens & rbtble curvature, and
usuauy Iii bafwaan the two ncirmsl sectibn fines
wttikh the two pohte determine. tf the M
t-1 pdnts are in naarfy the wna fslfiude,
the gacdaeb fbta may cross owe of the normal
eactbn lines. n should be nofed that, except
abng lhe Equator and abng the marfdtane, the
gaodesic llnalenot eptanacrsve end cennc4
Lw dghfed over directly. Hewcwer, for
conventkmal trfangulatkm the lengths and
dtiicna of gacdasic lines dtiar kmppreciabty
fmrn cm-responding pek’s d norrnel ~ion lines.
Also called gaodealc; geodetic Ilrm.
geodealc-sae geodesic line.
geodesy—lle science whkh deals with the
fb~inalion d the size and figure of the
Geodotlc Reterenco Systsim 1960 (GRS
BO)-Thta gaodatic reference systam was
ado@d by the XVII General Assembly of the
international Union ef &odesy and Geophysics
at Canberra, Australia in 1979. The GRS SO is
defined by the four fundamental mnetents:
aerni-mejor axis 6,378,137m, gravitatiomd
constent d the Earih (including Ihe atmosphere)
3,9S6.005 x 108 n# S-2, -nd degrae zonal
coaffiiienl 108,263 x l@, and anguler
relational velocii 7,292,115 x 10-11 radkms.
geodotlc ●td geophysical data (G6G)-
Infcrmat”mn or earth data, pertaining to the
sciences of geodesy and geophysics. Typicalfy
includes gravity infomralkm, geodetic peinf
posifiining data, datum definition, etc.
gciodotlc ●nd goophyslcal data
roductlo*The process of enhancing the
value of geodetii and geophysical data by
anefyais, evefuatien, computation, and
adjuatmant. The pmcaea includes (1)
transforming unadjusted survey data and
ebservafiona into an adjuafed form with reliability
afatemanfs; (2) establishing basic frameworks of
horizontal and va.ttiil cantml in advance of
-P. Chad, ad fargat rrwleriels pmducfion, snd
publiihmg d trig Iiita; and (3) arbsfyais,
evaluation, and campufalicn of geodetic and
!W@Yabl data obtained by awface, ahboma,
or tmteffife hschniquee to establish, exiend,
connect, and transform daturns and to relets
datum to the Dapamrranf of Defenea Workt
Geodetic System.
geodetic ●nomaly-Sea ●nomaly,
definiiicn 2.
geodetic ●dronomy-The branch of
gecdesy which Ufifiiee astronomic Obearvsfbns
to asfracf gecdatb Irkmnafiin.
goodetlc aztmuth mark-A rwked potnt
astsbfished in connection with a friengufatbn (or
tmverae) station to provide n starting azimuth for
dependent euwaya.
gaodetic ●zimuth-l%a angle between the
gacdefii meridian turd the tangent to the
geodesic fins at the chsarvar, measured in the
pklne peqmndiculet 10 Ihe allipaoid rrc.rmal of
the observer preferably cJockwiae from north.
Although older suweys, particularly by the Coasl
and Gaodatic Suwey (now National Geodetic
Survey), used sculh, the Daparfment of
Defense now uaas north.
geodatlc control data-information
concerning the pracise horizontal and vertical
geodetic bcetion of pints on the surface d the
Earth end ceiestkl bodies, includ@ points
obtained by phc.!ogmmmetric techniques.
geodatlc control—A system of horizontal
rmdlor vefiicsl mntrol statione that have been
esfeblishad and edjuslad by geodetic meihode
❑nd in which the shape and size of the Earth
(geeid) have baen considered in position
computat”mns.
geodatic coordinator—Tha quantities of
latitude, bngifude, and height (ellipse”@, which
define lhe posifiin of a point en the surface of
tha Earth with respect to tha raferance spheruid.
Also imprecisely called googrttphlc
coordinate.
gaodatlc
card.
geodetic
data sheet—See control data
datum—See datum, definition 2.
gaodatic equatOr-Tha line of zero geodetic
ktifude the uraaf circle described ly tb
semimejor asis d the reference alliisdd ea if ie
roteted about
aatronomlc
the minor asis.
●quator.
See also
103
geodetic he4ght-See ●lllpsoldel holght.