1 - NGA

trlsngulatlon aystenr-lhe main schema, or
nd,dprbrwya fafbnee ndfhaaudfbry
Cfetions. nterrdna shrrmaf ethafmmawwkof
Ifwayefem ardfaliadaf sav+maf* to
prrwiauafy aatsbfiahad triangulation stations of
equal or higher order. See also survey neL
definition 1.
trlangubtlon thoodolffe-$ee direction
Inatrumont thoodollte.
trbngufaflon tower-A afrudure ussd 10
elevste the Iirm of sight atxxe intwvening
obetecles. Usually wnsists of two independent
efruduras, one within the ofhan the osnter
sfwhtre s+portri the Umcdofiie end the outer
.stndure s-s the observer and the slgnel.
See also Bilby steel towor.
MIL-HDBK-850
bpogmpM ‘ survey,
es a hydrographic
wfmn it rmy baccxne )mown
or topogmphlc ●lgnal.
gmphy oM4ned by sirnuhanaous eXPSMe Of
ttwee cameras Syetemefkany I&$ezad m the Sit
vrrhisb cftimdo varb@nga r@aemtafivefo
trbngulatlon ststlon+JCS) A pcint on the each other m csder to mvar a wide f~. See
Eartfr* pasifii bdebrminad~.
elso fan camera photography.
trisngutefion. At60 cstfed bfg point.
trig control-see field control.
Mg doealor-A dafaUad reoud on the
ftfangufatti of en ems, giving the coordkwtse
d the triarrgldatbrr afationa.
trfg llst+fCS) A list pdiehed by serfairr Army
Urine Wtlidl itsludL9J e3eentbI HOrrrdii d
accumfefy bmted rwvay poirda. [A pibfidion
mntaining sII availebb puaibud data and
etavatii wffh the raspedva daacr@bne of
horizonfet andkv vettkad control points, uauatfy
arranged asawding to lhe focatiin of the cantml
points within the hits of map .shaefs of targsecele
eark.]
trig point-See trlnngulatlon atatlon.
trigorromatrlc Iavding-lhe determination
of dtfferencee c4 abvefiorw from observed
triangulation-l+ method of surveying in whiih verficat englea wmbined wffh Iangfha of lines. A
the sfeficns era @rrts on the. Ground whkh are. . ,fype of indiued bvekg.
IOcsfad et the vertices of a chain or network cd
triangtas. The angles 04 the trisngfes ere
measured instmmarrtaily and the .eidEs are
dwimd by canputetion from selected sides
wtriih are termed bime Ilnas, the lengths O}
whfc+r am obtafnad from direcd meeeurarnants
on the gmurxf. See ebo ●ralytfcsl thma.
point msectfon redlal triangulation; arc
triangulation; ●raa trlangulatlon; besa
neti dlmet radial Mangulatfon; firetordor
trlwrgutatlon; flare trlangulatlon:
graphical radial trlanguletlon; handtomplot
trlangulatlon; Ieocentar
trlangulatlon; mechanical-templet
triwrgutmtion; rmdlr-point trlangulatlon;
phototrlangulatlon; radial trlangulatlon:
‘ satellite trlenguletlon; second-order
trlwrgulatlon: aamlenalytlcal
triangulation; ship-to-shore
trtangtdatlon; stotted-templet
trlengulation: ttplder-templat
triangulation; third-ordor trlangulstlon;
trllateratlon.
trlaxtal ellipsoid-An eltipaold having three
U~USl axes, the etwxfesf being ifs potar exia,
while the two bnger onec lie in the pfsrre of ifs
equator.
trlcamora photography—(JCS) Photo-
267
trltetertrtion nat—A network of points W*
positiis relsttie 10 one another aro determined
by maeeuremenf end edjuafmanf of the length
of the aides of the frierrgtes formed by these
points.
trllateretlon-A method of surveying wtrereln
the Iengfhe of the trisngle aides are maeeumd,
ueuefty by ebcfrotk methods, and the angles
are rnmpufed from the measured lengths. SeS
also trlmrgulatlon.
triiinear ●urvayhrg-The determinatbn of the
pesirii 64 e pohrf of observation by measuring
the engles at that point betwean fines to three
points cd known Poaiiion. See afso resection.
trim marfm-Unae plasad on originel copy to
serve as guidas in cutting or trimming the
printd sheets to their prescribed size.
trim dze--(JCS) The size of e mep or chml
sheet tiarr the mmaas papar ouleide the
me~in h= been trimmed off after printing.
trlmetrogon camwe—A triple samere
essembty with one vertical and two fried-angls
obliques wfmse imegery overlapped the vertical