1 - NGA

dleplacsrment; Illt displacement; xdlsplacement;
y-displacement.
display—The graphic presentation of the
output data 01 any device on system.
dlmolve-(digifal) The process of removing
shared common attributes by eliminating the
shard boumtarias when merging two or mora
polygons.
dletanca sangle-An angle In a ttiangle
ofWOstie a side used as a basa in the solution
01 the Mangle, or a side whose length is to be
computed.
dltstenco measuring ●quipment (DME)-
See electronic distance measuring
equipment.
dkstance prorate rule-A method of
bel.ancing a survey. A rule for holding angles to
their racorded values and pforatlng the lengths
of the lines In the traverse; oparaled by locating
the beartngs to a wnvanlenl meridian,
preferably the cbsing fine of the traverse, and
prorating the dimensions through a
trigonometric precess.
distance-lhe spalial separation of two
poims, measured by the length of a line joining
them. Sea also ●ngular dlatanm; double
merldlan d18tance; double zenith
dlstanca; ecllptlc polar dlatence;
electrical distance; external dletstnce;
felllng; front focal distance; great-circle
distance; grid length; ground distance;
hyperfocal distance; Interocular
dlatance; lunar dietance; merldlan
distance: marldlonal distance; plus
dletance; potar dlatance; prhtclpal
dletance; projection dlatance; relatlve
distance; rhumb Ilne distance; slant
range; Sun-zenith distance: tangent
dletence; time dletance; zenith
dlatance.
dlatant polnte-Similar to tie poinls but which
appaar only on the obllques lacing outward on
the perimeter of a mmpilation. Distant points
unfte the sets of a sfrlp Into a flight unit; bul,
unlike tie poima, do not serve to join several
flight strips together.
dletortlon compenaatlon—
(photogrammstry) In a double projection direct
viewing pbffer sysfem, that corracflon applied to
offset the effect of radial distortion introduced in
MIL-HDBK-850
74
an original negative by the objective tens of an
aerial camera.
diatortlon curve-A curve represeming the
finaar distoflion charactarbtka of a tens; ii is
plotted with image radial dislance from the lens
axie es abscissae and Image radial
dbplacements as ordinatas.
dlatortlon-Lens aberrations affecting the
posltbne of Images from their true relative
poaitiirrs. See also aberration, detinftiorr 2;
angular dlstortlon, definl!ion 2; dllferentlal
distortion; flim dlaforllon; Image
dlstortlon; Image motion Compenaetlon
dlatortlon; lane dletortlon; linear
dlstorflon; panorsmlc dlsitortlon; radial
dlatortlon; seen poeltlonel dlstonlon:
tangantlal dlatotllon; tfpped panoramic
dtatortlon.
distributed data baaa-A data basa with
unique mmponents in geographically dispersed
locations finked through a telemmmunications
netwok
dlstrlbutlon map-A map which shows the
geographic arrangement of a specific product,
commodity, or formation.
dleturblng tunctlon—Sse dlaturblng
poientlal, definition 2.
Uiaturblng potential—l. (geodesy) The
difference betwean the gravity potarrtial of the
actual Earth and the potential function of tha
normal gravity. Also called potantlaf
dleturbance; potential of disturbing
maaaes; potantlal 01 random maaeaa. 2.
(astronomy) The diffarerrca bafwaen the total
gravitational potential and the pofemial
petlaining to a spherbel mass dbfr~}on. Abo
called disturbing function,
diurnal aberration-Aberration reaufring horn
the rotation of me Earth on Rs asis. The value of
diurnal SberfafiOn varies with the latitude Of the
observer and ranges trom zem at the poles to
0.32 second of arc al the Equator. A correction
tor dlumal aberration Is applied to astronomic
ObSeNatlOflS for longitude and azimuth. Also
called daily aberration.
diurnal age—Sae aga ot diurnal
Irrequaflly.
dfurnaf arc—See aetronomlc arc.