1 - NGA

land boundary-A line of demarcation
fmtween two parcels of land.
land effect-See coastal refraction.
land mass slmulat~r plate-See
fsctorad transparency.
land survey-The process of determining
boundaries and arsas of tracts of land. The
term csdastral survey Is someflmea
used to dasignaia a land survey, bui in this
country lls use sfwuld be restricted to the
SUfVeyS Of public lands of the United
S!atea. Also called boundary survey;
property survey. See also cadastral
survey.
land-line adjustment—Posltionlng lhe
public land fines on a topographic map to
Indicate their true, theoretical, or
epproximata location relative to the
adjacent tarrain and culture.
landmark-l. An object crl enough Interest
or prominence in relation to iis surroundings
to make ii outstanding or to make it useful
In determining a location or a direction. 2.
Any monument, material mark, or fixed
object used to dasignate the location of a
land bmndary on the ground.
LAN DS,AT—The generic name for a series of
aarfh obsewlng satellites, fimt launched in
1972 by NASA. IANDSAT serves as
plaffomns for several sensors, including the
Return Beam Vidlcon (FiBV), Ihe
Multispectral Scanner (MSS), and the
Thamatic Mapper (TM). Originally named
ERTS, for Earlh Resources Technology
Satellite.
Iandacape map—A Iopogrephic map made
to a relatively large scale and showing all
datails. Such maps are required by
archnecfs and landscape gardeners tor use
in planning buildings 10 fit the natural
tolmgraphic teatures and for landscaping
parka, playgrounds, and private eslates.
These are generally maps of small areas,
and scales vary from 1 inch -20 feet to 1
foot = 50 feet, depending on the arrwunl of
detail.
Laplace azimuth mark—An astronomic
azimuth mak at a Laplace Station.
MIL-HDBK-850
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Laplaca azimuth-A geodetic azimuth
derived trom an astronomic azhrsutn by use
01 Ihe Leplaca equation:
Laplace condltlon—The Laplace condition,
expressed by the Laplaca equatbn, arises
horn the facf Ihal a deflacf”bn of the vertical
in the plane of the prima varfkel Ml gtva a
differanca between astronomb and
geodetic bngitude and bafwean
astrurromic and geodetic azimuth; or,
conversely, that the obsewed differences
between astronomic and geodatc valuaa of
the Iongilude and of the azimuth may both
be used to determine the dellacfion in the
plane of the prima varticel.
Lapface control-Con!rol and correction of
astronomic azimuths through observations
of Ihe deflection of the plumb line in the
prime vertical (comparison or astronomic
and geodetic Iongilude).
Laplace equation—l. The equation which
expresses Ihe relationship between
astronomic and geodetic azimuths In tarms
of astronomic and geodetic bngiludes and
geodetic latitude. 2. (~tenlial) A pariial
differential equation of the sacred-order
which is satisfied by the Newlonian
potenlial of every finite body at all exterior
points.
Laplece station—A triangulation or traverse
station at which a Laplau azimuth is
determined. Al a Laplace atafion both
astronomic longitude and astronomic
azimuth are dalermined.
Iarge-scale map—(JCS) A map having a
scale of 1:75,000 or larger. Sea also map.
Iaaar Ierraln profile recordar—An
electronic instrument that emits a
continuous wave laser beam from an
aircratt 10 measure vertiial dbtartcas
between the aircraft and tha Earths
surface.
lasar—A devica producing coherent energy
beams in the spectrum of Iighl or near-iiiht
frequancias. A .Iaser-equipped Geodimetar
makes it possible 10 measure greater
distances.
Iatant Image-The invisible image produced
In radiation-sensitive materials which