1 - NGA

I
I -..
I
measurements ob!ainad by echo aoundksg
equipment. Alao called echogram.
fat horn curve-se a daplh contour.
fathom llna-See depth contour.
Fathometer—A trade name for an echo
aoundar.
Fssye ●nomaly—Sac free.alr anomaly.
Faye correctiort-See free-air correction.
‘ibiL-tibBK-850
featheradglng-1. (cartography) The
technique of progressively dropping contours, to
avoid congestion on ataep slopss, and taparfng
ihe fine weight near the end of the contour to be
dropped, Aleo called leelherlng, 2.
(photormaabklng) The thinning of overlapping
edges of photographs bafore assembling into a
mosaic in order to rnaka match fiiaa lass
nolicaable. Whan ovarlepplng edges are
Iealhared, shadows and sharp changes In
mmraaf are reduced or eliminated. Also called
feathering.
feathering—See teatheredglng.
Feelure ●nd Attribute Coding Catalog
(FACC)—DMA Glossary which contains the
Feature and Attribute Coding Standard (a
nmdiiisatbn Of DMA’s FACS), See
Faature/Attribute Coding Standard.
Feature Extrectlon Segment (FE/S)—A
segment of DMAa MARK S5 which implememe
a mrn~ter suppmtad, analytical steraoplotter
system capable of extracting Iaature data. This
segment intagratea, on a sfngle system, all ot
Iha varbus Stapa involved in the mostly manual
feature extraction process prior to DPS. See
alao MARK 8s; Dlgltal ProductIon
System.
feature analyals codo (FAC) number-A
unique number (usually sequential) assigned to
each area or Ieature ce.rfraved on the feature
manuscr@ arm used iO rel~te Iealtire aislysis
data @da (FADTJ information to the digital
information which portrays the shape 01 the
feature. See also faature analyala data
table.
feature erralyala deta table (FADT)—A
tabfe mntaining the teature anafyais rmde
numbers and the numeric codes whkh
,
represent the physical characferfstka of features
aelecfed for portrayal. Sea also feature
analyala coda (FAC) number.
taature analyala-The process of locating,
examining, and classifying the physiml
characferiatka of cuftural Ieatures on the earth%
surface.
faeture attrlbuta-A property of a feature.
faature claaa-A aet of teaturee ahartng a
mnsistem set ot attribute types. A leature ctass
Is irr’@ememed by using a set of tablee that
Includes at least one primitive table and al least
one attribute table. A feature class has fhe
same columns (aftrfbule types) ot attribute
irrforrnatbn tor each teature. Cfasses o! Ieatures
are creatad in order to allow the rafational model
10 oparala on them as sals. Every feature cfaas
has one and only one feature tSble.
feature coda-A unique identifier assigned to
a feature.
teature extraction—The arf of extracting and
classifying features mntained in an image.
teature Identl?lcation data (FID)-
Intormation pertaining to the classification of a
teature as to kind, tunction, and deacriptiin,
e.g., heavy fabricaflon Industry wfth aaw-toelh
roof; fruss bridge; powerfine pylon, etc. Each
classification has a unique feature ktentfiication
coda. See also featura anelyala data
table, Iaatura enalysia code; featura
analyals.
faatura table—A table made up of the
primary-keyed rows ot the features in a laature
class. These rows mliecfively form the feature
fable for that feafure class.
Ieature typa-A classification of featuras into
three categories: (1) poim of faatura-an objea
whose location can be dascribed by a alngle set
of coorcWmtee; (2) Iinaar (or Iinas) taaturaporfrayed
by a line that does nol repraserrf an
area; (3) areal fealura-a topographic feature,
such as sand, swamp, vegetation, etc., which
axtends over an area or in digital mapping any
area encbsad by a delirrdfing Iina thaf has any
unique characteristic, a,g., induafriaf araa, forest,
residential area, etc. Feature type is thus an
attribute defining ffse fopologic proparry of a
feature (poinf, fine, or area).
feature. oriented-A term used to describa
92