Glossary
A-D | E-F | G | H-I | L-M | N-P | Q-S | T
Earth satellite thematic sensing
Landsat satellites have a Thematic-Mapper (tm) sensor that produces
images in many spectral regions, e.g., in the visible range, in the
near-infrared, in the mid-infrared, and in the thermal infrared. The
visible and near-infrared regions provide information on water turbidity,
bathymetry, currents, and sediment plumes. (Water containing large
quantities of suspended sediment has a higher reflectance than clear
water and can be easily separated using satellite data). The near-infrared
band is used for vegetation mapping since it distinguishes features
by variations in plant cell structure. Mid-infrared spectral regions
reveal plant water content and help delineate vegetation type. Two
mid-infrared bands are used for geological studies and one for collecting
imagery at night and identifying hot objects, such as forest fires,
lava flows, emissions from smoke stacks, new construction, and soil
use.
Elastic body transformation
A least-squares computer software program run against a raw digitized
data source map to produce a geographically true "X" and
"Y" coordinate database referenced to any standard map system.
Based on the locations of control monuments, a "best fit"
is made to the source map's origin, rotation, scale, skew, and stretch.
If the source map's systematic errors were small, an accurate "fit"
will be made resulting in small residual errors. Also called rubber
sheeting and coordinate rotation/translation.
Facility area map level
A map definition level of a virtual map. It describes the street,
water, sewer, gas, electric, phone and cable networks together with
the cumulated structures developed to meet the needs of the people
within the land area. The facility area data files describe and define
the street network and street facilities of the area with locational
coordinates associated with the facilities and supplemental identifiers.
The facility definition (street network), when related to spatial
display, uses a base geography area definition. A GIS provides a framework
for data manipulation and display of map data especially for: (a)
location verification, (b) location correlation, (c) locational relationships.
(d) district coding. (e) route analysis, (f) area analysis and (g)
mapping/display creation.
Facilities management system
Facility mapping
GIS technology applied to the information in a database pertaining
to public or private facilities as utility or engineering facilities,
i.e., electrical stations and distribution lines, water reservoirs
and distribution lines, natural gas lines distribution, telephone
lines distribution, sewer treatment plants and collection lines, streets
and roadway systems, etc., of an area having a map reference which
has the ability to be represented by symbols and data on the maps
drawn by a computer mapping system. The user of the FM system can
direct it to select any one pole or facility, or it can access all
data poles or facilities in a region, zone, city block or any area
designated, regardless of size or shape. It can also cross-reference
and access the records of the pole or facility, such as size and type,
inventory number, date of installation, date of last inspection (plus
results), and other equipment installed on a pole and access the account
numbers of the customers whose service drops emanate from a pole.
Forest management system
GIS technology applied to providing and maintaining a continuous supply
of wood fiber while balancing environmental (e.g., a forest home to
whitetail deer, moose, black bears, bald eagles, and other wildlife),
social (e.g., thousands of people enjoying the forest area for hiking,
rafting the whitewater, fishing and hunting), and regulatory factors.
This system provides the means to analyze the land base relative to
the amount of wood actually available for harvest, with consideration
for applicable regulations. This allows appropriate harvest scheduling
and timber supply analysis, e.g., timber volumes by species and product
are multiplied by cover type acreages to arrive at estimated inventories.
Regulatory zones for streams, lakes and rivers, and wildlife management
are mapped and assessed for their impact on wood supply that allows
for keeping track of all diverse demands on the land and the variety
of constraints on timber availability. The system includes forest
stands, all roads, hydrology and political boundaries, which allows
use of the system for management activities such as harvest, planting,
vegetation suppression, thinning and road construction.
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