1 - NGA

measurements obtained by echo sounding
equipment. Also called echogram.
fsthom curva-.See ctaplh contour.
fathom llne-See depth contour.
Fathometer—A trade name for an echo
sounder.
Faye ●nomaly-See fre-alr anomaly.
Faye correcflon-See free-air eorractlon,
MIL-HDBK-850
featheredging—1. (cartography) The
techniqua of prograsslvely dropping contours, to
avoid congestion on steep slopes, and tapering
the line we”ght near the end of the contour to be
droppad. Alao called faatherlng. 2.
(pholorrmaaiddng) The thinning of overlapping
edoes of Dhotooralstrs befora aesemblino into a
mc-saic In “order-to “make match lines les~
noticaabte. Wfsan ovarkpplrrg edges are
feathered, shadows and sharp changes in
contrast are reduced or eliminated. Also called
feathering.
isratherlrrg-See taatheredg}ng.
Feeture ●nd Attribute Coding Catelog
(FACC)—DMA Glossary which contains the
Feature and Attribute Coding Standard (a
modiiilbn o! DMA’s FACS). See
Feaiure/Attribute Coding Standard.
Feature ExtractIon Segmenf (FE/S)—A
segment of DMA’s MARK S5 which Implement
a mrrtpster supported, analfilcal slereoploffer
system capable of extracting feature data. This
segment integrates. on a alngle aystam, all of
the various atepa “revolved in the mostly manual
feature attraction pmcasa prior to DPS. Sae
also MARK 85; Dlgltal ProductIon
Sy*tem.
feature ●nalyala code (f AC) number—A
unque number (usually sequanfial) assigned to
each area or feature portrayad on the feature
manuacr@ ar-sl used to relata feature analyais
data tabfa (FADT) information to the digital
irsforn?dticn whkh partrays the shape of fhe
feature. See also Iaature analyels data
table.
faature analyala data fable (FADT)-A
tabfe containing the feature anatyais code
numbers and the numeric codes which
represent the physkal characferfstba of features
selectad for portrayal. Sae afSO feature
analyata code (FAC) number.
feature analysla-The process of bcafing,
examining, and classifying Ihe physkal
characferfafica of cuffural features on the earlh’s
surface.
feature attrlbuW-A properly of a feature.
faafure claee-A Sel of feafures eharfrrg a
consistem set of affrlbute types. A feature class
is irr@emerrted by using a aet 01 fablea that
Includes at least one primitive tabte and al Iaast
ona attribute fable. A feature class haa the
same mhsmns (attribute types) of atfrfbufe
Information Ior each Iaature. Cfasses of features
are created in order to allow the relatkmal mdel
to operata on fhem as sets. Every feature cfass
has one and only ona feature table.
faatura coda-A unique identifier assigned to
a teature.
feature extraction—The arf of exfracficg and
classifying features contained in an image.
feature Identlflcatlon data (FID)-
Information pertaining to the dass~cation of a
faature aa to kind, function, and dascrfptkrn,
e.g., heavy tabricafion industry wfth saw-footh
rool: lruss bridge; powerfhne pylon, etc. Each
classification has a unique feature identification
code. See also feat ura anal yala daf a
table, faature analyala code; feature
analyala.
featura fable—A table mada up of the
primary-keyed rows of the features in a feature
class. These rows collectively form the feature
table for that feature class.
faature typ*A classification of features into
three categories: (1) point of feature-an objea
whose Iocariin can ba described by a single aet
of coordinates; (2) linear (or lines) featue
pomayed by a iine that doea nol represent an
area: (3) areal feature-a topographic feature,
such as sand, swamp, vegetation, etc., which
extends over an area or in d~ifal mapping any
area encbsad by a delimiting line that haa any
unique characteristic, e.g., industrial area, forest,
residential araa, etc. Faature fypa is thus an
attribute dafining fhe topologic propady ,of a
Ieature (point, fine, or area).
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leature.oriented—A term used to describe