1 - NGA

equator of ns fnimary from north to south.
~sne of ●scondlng node. IWO called
southbound nod..
MIL-HDBK-850
dencondlng vertlcsl sngle-Srre angle of
depression.
dMC?lptlOI+l. A Ierrn for the formal
pubflehad dafa of eaCft trlar@atbn SfatlOn,
bench merk, etc. The data Include Informalbn
of the focaflon and type of mark and enable
anyone to go to the Immediate iocafitiy and
klantify the mafi with certainty. 2. (cedastraf
surveyin@ A dorarmsnt listing the metes and
btmds of a property.
descriptive name-(JCS) Written indication
on maps or charfs used to specify the nature of
a Ieature (natural or artitiiial) shown by a
general symbol. See also OeoQraphlc name,
place nama, and Ioponym.
Design Concept Review (DCR)—A
milestone in tha development of a syslem
where the review team determines if the
raquirsmants hrrpossd are Iully underwood by
the daveloper and are completely accounted for
and delemrines if the System Design
Architecture is reasonable and Ieasible. The
requirements must be allocated to hardware,
software, and operations.
delall pohttbSelected identified points,
especlalty on ob~que photographs, used to
assist in cwmctiy positioning leatures displaced
as a result of elevation.
detalllng—(surveying) The process of tying
topographic details to the control net. Objects 10
be Waled in a survey may range from single
points to mearutanng streams and complex
geological torrnations.
detection—in Imagery infetpretation, the
discovering of the existence of an object but
withwt reoognltion 01 the object.
develop (dovelopmenl)-in photography, to
subject to the eotbn of chemical agants for lhe
PUPOSe Of bringing to VISW the Invisible or latent
Image produced by the acfion of light on a
SenSfliZSd surface; a160, 10 produce or render
visible in this way.
developsblo—A surtace that can be flattened
to form a plane wilhout comprasslng or
stretching any pafl of ft, such as a cone or
cylinder.
devlstlors-(JCS) The angular ditterense
between magnstii and compass haadinga. Also
called magnetic devlatlom See also erroc
residual dsvlatlon.
diagnostic polrtl-A point wlthkr a data sat
with accwrste and known gsographk location
that Is used to verify the edequeoy or
inadequacy of transformatbn raeuff to the dSta
set. (The diagnostic point ia not part of ttte
transformstiin sotutiin.)
diagonal check-fdeasuremente made
across the opposite comers of the bask trams
of a map projactlon to Insure the aocuraoy ot Ita
COnStWCfiOn, or to establish ancVor check the
scale of reproduti!on.
diagram on the plane of the celeatlal
equelor—See time diagram.
diegrsm on the plane of the colesllal
marldlart-A diagram in which the local
celestial meridian appears as a circle with the
zenith at the lop, and tfre horizon as a
horizontal diameter. See also time diagram.
diagram’s% “the--plane of the
equlnocllel—See time dle.gram.
diameter enlargement—A term used to
indicate tha degree of enlsrgarnent of rXi@naf
COPy. A One-diaITIeIer enlargement of a 4- by 5inch
original would tm S by 10 inches. See alSO
tlmea (X) enlargement.
dlemeter—(magnification) See magnifying
powar.
diaphragm Stop—See relative apsrature.
dlapoeltlve printer—A phofographlc device
for producing dlaposltiies trom aerial nsgativea.
Also called reduction printer. See alaO
fixed-ratio projection printer.
dlaposftlvs—(JCS) (photogrammetry) A
pesitive photograph on a transparent medium.
The term is generally used to refer to a
transparent positive on a glass plafe used In a
plotting instrument, a projector, or a mmparator.
dlfferenca of elevatlon—Ttie vertical
distance between two points, or the vertical
distance between the Ieval surfaces that pass
through fhe two points.
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