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co~ected for scale, recttiled, and fskt to ground
corrtml to provide an acwrata represemalbn of
dletancas and diracfbn. See also mosaic;
somlcontrolled moaalc; uncontrolled
moeetc.
COtTtrOlllng depth—The Iaast dapth in tha
qroach or channel to an area, wch as a port
or anchorage, governing fhe masimum draf! 01
craft fhaf can enter.
control-t. Previously esfabllshed posiiions
ardor ortentalksn data used for determining
addffbnsl ~sifbn data used for diecrsle
to~phk polnfa, or for oonfrolllng
cartegraphc rapreaanfations 10 tha specifiad
datum. 2. A mllacfive term for a ayafem 01
marks or ol$ecfs on the Earth or on a map or a
photograph, whose positions or elevation, or
both, hava been or will ba determined. See also
eetronomlc control; basic control;
common control; olactrorrlc control;
geodetic control; ground control;
trorizontel control; La place control;
Iavel control; photogrammetrlc control;
recover; sterlhtg control; supplemental
control; verflcal control.
conventional International otlgln (CIO)—
The average terrestrial pole of the perbd 1900
fo 1905. Olsen used as tha origin to which the
coordnataa of the instantaneous pole of
rotation of the Earth ara ref errad, In 1967, fhe
IUGG recommended that the C)O be usect to
define the direcfjon 01 the geodetic north pole.
Abbreviated to OIC In French pubticatbns. See
also everage terreatrlal pola.
convergence conetant-Tha angla at a
L?ivanIathuda between merktians 1” apart.
Somatlmas loosely called convergency, a
larm whkh more propsrfy Is the equivalent of
convergence.
convergence of merldlena-The angular
drawing togathar of tha geographic meridians in
passing from Iha Equator 10 the poles. A! the
Equator, all meridians ara mutually parallel;
pasaing from the Equator, they converge until
thay maet at tha polas, Infereecfing a? angles
that are equal 10 their differences of Iongifuda,
The tarm converganca 01 marldlana la
usad to daslgna!e also Ihe relative difference of
direction of merWan6 al Speclfk points on lhe
meridians. Thus, for a geodatic Iina, the azimuth
@f one end differs from fire ezimufh al the other
end by 180° plus or minus Ihe amounl of fhe
oarrvergence of the merldlans at fha and points.
‘MIL-HDBK-850
convergent camara—An assetily of two
aertal cameras which take .sknultaneous
pfzofogmphs and nsaimain a fixed angla
between their opfkal axea. The eflact is to
increasa tha angular covarage in one diracfbn,
abng the longitudinal asis of fhe aircraft.
convergent model deturrr-See model
detum.
convergent photography- Photograph y
taken with a corwergenf camera. In
photogrammewy. the angle of wrwergance of
the two lenses asas Is usually 40” mainfainirrq “a
1:1 base-height ratio. I
convergent poaltlor+A split camara
installation so positioned that fha plane
containing the camera axis is parallel fo lhe line
of ftiiht.
converging lene—See poaillve Iena.
conversion angle-(JCS) Tha angle batwaen
a greatdrcle (orfhodmmk) bearing and a rtwmb
line (Ioxodromic) bearing of a point, measured at
a commen origin. ,. ... . . .
converalon fnctor—A quantify by wfslch the
numerical value in one system of untts must be
mutfiplied 10 antve al fhe numarbal value In
arsolhar system of units.
conversion acala-(JCS) A scale Indksling
the ralatlonshlp between two diffararrt urrffa of
measurement (e g., maters to Iaet). See also
acele.
convaralon—The changing 01 ona aystam of
meawreman! to another; e.g., converting
meters to feet. Conversbn Is usually
accomplished by the use of conversion factors,
scales, and tablas.
convarflbla lens-A lens containing tsm or
more elemants which can be used individuality or
in wmbination.
convex lana—See positive Iene.
cooperaltve mapping agreement— A
formal agreemem between nafional
govammaMs speclfylcg responslblllfles for
MC&G ecfivities such as procuramenf of aerial
photography, execution of gaodelic COIW’01
suweys, and production of maps, charts, and
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