1 - NGA

vacuum box-The frame, wrrfeinirrg ils own
Vssuum unit, Whfch encfmes the rrmkf fer the
fermktg d pfeafii refid maps.
Vaia81a Comp*retor-A precise dbtarrce
measuring Inatrumsrrt thel uses c@icel
imarferometry for making masauremsnfs. h can
reassure distensas ss grast as MM meters with
Ofr===Ydl Wfmlo7.
value-Sas abaoluto VShlO; ●d]usted
valrm; most probablo value: obaanmd
valrm; tru. value.
vanlshlrrg llna-The straight fine on a
photograph t@n which lie 811the vanishing
points of all aystema ot psrellel lines psrallsl to
one plane.
vanlshlng paint-l%e knege, in the pfane of
a ~~~h. of the peint towmd whish a
system of parallel firrEs in ths .3@ect spsce
mnvergas.
varlablo contour interval-A nonuniform
mrrtour intsrvsf. ft msy rssuft tmm the U6S of
cartogrsphk source me!erkrls which do not
so~in a constant sentour interval er from
ade@ng the oortteur interval to specifii types of
Wrmfn for the optimum perfrsyal of diet
fsstures.
varfabfa Iongth field-A field WIWSS length is
determined by the amount ef sforege needed 10
atom ifs contents. Useful for chsresfer strings and
ceotdhs:e atrfnga, both of wh~h are huhty
vsriabfa in length.
variable fanrnh recorde—These remrds may
heve a variabl-e number of fiefds (dele elemantsj
or the fields msy be of varying fsngfh, or both.
Verieble-fmgth mmrde typiilly hsve defimifsd
fiekls atior &yie murrts to fediiate pmcsseing.
Sss also fixed-length records.
varlabfe perspective camera system— A
system whti, in its simpfsst fwrn, mnsisfs of a
rAemJard+pa view camsrs, a Isrge eparture
front-surface mirror of spherical mnfigumfiin.
end en eesal used in tfrs recfifiiticm of highfy
tifted bng focal-length phetegrephs, and the
trsnaformstion of maps and charts fmm one ,
projecflmr to another. When the csmera
MIL-HDBK-850
v
2 74
mnponeM krqkced wifhapm@fOr, if
~ possibk 10 expedite the recfifkationof
Iuner pt@Ogmpfy tekan by terrsetriel
observatori8a.
variable ratio pantograp&S e e
pantograph.
verWrco(u2~Tha most SornmOnly used
measure of d- or error In atstiatkef
ansfyeia. ffieefao oelfsdthe mesnaquered
davietii. Vaderroe is cdctdsrd by ri tddng
fhaeumof thaaqusM davWonshomtha
mean fof each of n cbaervetiens. Then the sum
is dii”tied by n-l.
varlatlorr of coerdlnato rrmthod- A
malhcd et e@a~mg massursrrrants in wtriih the
mordinetas of geodstk points ere varied so as
fo bsst fit the obaarvstiorm snd retain
msthemstlcel Ivwmrgeneity. Sea obaawatlon
equationa; varlatlon of perametera.
variation of latftude-A 6MsII dwmge in the
astronomic isthude of points on the Eerfh, due
to V.srfet)orl d fhe @es.
varletlon of pamrneter-1. An interactive
msthcd to edvii mm@ex equations by
successively cJeam epproxirn=dkms of tha
variables, usuelfy arnpl@ng the more rrignifiint
terms of the rust dsrivatiwes c4 msthemstioelty
prsciss funcfiens thst must equal zero cdy
when the correct vefuas 64 the variables sre
uti to compute the funcliorw. 2. The
okmrvsfksr eqlaMona method of beef squares
adjustment is eemafhnss referred to as the
varfation of parameter mctiod of Iosat
●quaras sdjuatment bmausa the
peremetam of ebservat”km equetlmrs era
determined by varietion of perametem.
varletlon of tha poles-A small variation of
the Imetkrn et the irr.stantanseus exis of rotation
of the Eerth with rseuecf to the ohvsicsl surface
thereof. Also called “polar motion. see elso
conventional Intarnatlonaf origin.
varlstlonal lnaquallty-An Inequality in the
Mean’s rnetien, due msinly to the tangential
m~nent of fhe Sun’s attraction.
varlstIon—See magnatlc varlatlon.