1 October 2003
subsequent transmission during a station overpass. The average
instantaneous field-of-view of 1.4 milliradians yields a LAC ground
resolution of approximately 1.1 km at the satellite nadir from the
nominal orbit altitude of 833 km.
Large Area Crop Inventory Experiment
Lambert Azimuthal Equal
Azimuthal projections are formed onto a plane, which is usually tangent
to the globe at either pole, the Equator, or any intermediate point. The
Lambert Azimuthal Equal Area projection is a method of projecting
maps on which the azimuth or direction from a given central point to
any other point is shown correctly and also on which the areas of all
regions are shown in the same proportion of their true areas. When a
pole is the central point, all meridians are spaced at their true angles
and are straight radii of concentric circles that represent the parallels.
This projection is frequently used in one of three aspects: The polar
aspect is used in atlases for maps of polar regions and of the Northern
and Southern Hemispheres; the equatorial aspect is commonly used for
atlas maps of the Eastern and Western Hemispheres; and the oblique
aspect is used for atlas maps of continents and oceans.
Lambert Conformal Conic
The Lambert Conformal Conic Projection is derived by the projection of
lines from the center of the globe onto a simple cone. This cone
intersects the Earth along two standard parallels of latitude, both of
which are on the same side of the equator. All meridians are
converging straight lines that meet at a common point beyond the limits
of the map. Parallels are concentric circles whose center is at the
intersection point of the meridians. Parallels and meridians cross at
To minimize and distribute scale errors, the two standard parallels are
chosen to enclose two-thirds of the north to south map area. Between
these parallels, the scale will be too small, and beyond them, too large.
If the north to south extent of the mapping is limited, maximum scale
errors will rarely exceed one percent. Area exaggeration between and
near the standard parallels, is very slight; thus, the projection provides
good directional and shape relationships for areas having their long
axes running in an east to west belt.
The Landsat program, first known as the Earth Resources Technology
Satellite (ERTS) Program, is a development of the National Aeronautics
and Space Administration (NASA) in association with NOAA, USGS,
and the Space Imaging. The activities of these combined groups led to
the concept of dedicated Earth-orbiting satellites, the defining of
spectral and spatial requirements for their instruments, and the
fostering of research to determine the best means of extracting and
using information from the data. The first satellite, ERTS 1, was
launched on 7/23/72. The second satellite was launched on 1/22/75.
Concurrently the name of the satellites and program was changed to
emphasize its prime area of interest (land resources). The first two
satellites were designated as Landsats 1 and 2. Landsat 3 was
launched on 3/5/78. Landsat 4 was launched on 7/16/82. Landsat 5
(launched 3/1/84) is currently in service providing selected data to
A form of nondirectional digital filter.
An experiment first carried on the Space Shuttle in October 1984.
Light artificially stimulated electromagnetic radiation: a beam of
The angle between a perpendicular at a location, and the equatorial
plane of the Earth.