G-9
Glossary
SDTS the Spatial Data Transfer Standard, a “neutral”
file format for geospatial data, allowing it to be
imported into various geospatial software programs.
Seamless Server an online utility used by the USGS
for the download of different datasets, including
elevation data.
Selective Availability the intentional alteration of the
timing and position information transmitted by a GPS
satellite.
shadow the shadings in an image caused by a light
source. An element of image interpretation.
shape the form of objects. An element of image
interpretation.
shapefile a series of files (with extensions such as .shp,
.shx, and .dbf) that make up one vector data layer.
shortest path the route that corresponds to the
lowest cumulative transit cost between stops in a
network.
single frequency a GPS receiver that can pick up only
the L1 frequency.
site and association the information referring the
location of objects and their related attributes in an
image. Used as elements of image interpretation.
Site Suitability the determination of the “useful” or
“non-useful” locations based on a set of criteria.
size the physical dimensions (such as length and
width) of objects. An element of image interpretation.
skewed when the unreferenced image is distorted or
slanted during the transformation.
SKP file the file format and extension used by an
object created in Google SketchUp.
SLC the Scan Line Corrector in the ETM+ sensor. Its
failure in 2003 causes Landsat 7 ETM+ imagery to not
contain all data from a scene.
slope a measurement of the rate of elevation change
at a location, found by dividing the vertical height (the
rise) by the horizontal length (the run).
slope aspect a determination of the direction that a
slope is facing.
small-scale map a map with a lower value for its
representative fraction. Such maps will usually show a
large amount of geographic area.
SOS Science on a Sphere, a NOAA initiative used in
projecting images of Earth onto a large sphere.
space segment one of the three segments of GPS,
consisting of the satellites and the signals being
broadcast from space.
spatial analysis examining the characteristics or
features of spatial data, or how features spatially relate
to each other.
spatial query selecting records or objects from one
layer based upon their spatial relationships with other
layers (rather than using attributes).
spatial reference the use of a real-world coordinate
system for identifying locations.
spatial resolution the size of the area on the ground
being represented by one pixel’s worth of energy
measurement.
SPCS the State Plane Coordinate System used for
determining coordinates of locations within the
United States.
SPCS zone one of the divisions of the United States
set up by the SPCS.
spectral reflectance the percentage of the total
incident energy that was reflected from that surface.
spectral resolution the bands and wavelengths
measured by a sensor.
spectral signature a unique identifier for a particular
item, generated by charting the percentage of
reflected energy per wavelength against a value for
that wavelength.
SPOT a satellite program operated by the French
Space Agency and the Spot Image Corporation.
SQL the Structured Query Language—a formal setup
for building queries.
SRTM the Shuttle Radar Topography Mission, flown
in the year 2000, which mapped Earth’s surface from
orbit for the purpose of constructing digital elevation
models of the planet.
Standard Deviation a data classification method
that computes class break values by using the mean
of the data values and the average distance a value is
away from the mean.
standard false color composite an image arranged
by placing the near-infrared band in the red color gun,
the red band in the green color gun, and the green
band in the blue color gun.
StateView the term used to describe each of the
programs affiliated with AmericaView in each state.
Glossary
SDTS the Spatial Data Transfer Standard, a “neutral”
file format for geospatial data, allowing it to be
imported into various geospatial software programs.
Seamless Server an online utility used by the USGS
for the download of different datasets, including
elevation data.
Selective Availability the intentional alteration of the
timing and position information transmitted by a GPS
satellite.
shadow the shadings in an image caused by a light
source. An element of image interpretation.
shape the form of objects. An element of image
interpretation.
shapefile a series of files (with extensions such as .shp,
.shx, and .dbf) that make up one vector data layer.
shortest path the route that corresponds to the
lowest cumulative transit cost between stops in a
network.
single frequency a GPS receiver that can pick up only
the L1 frequency.
site and association the information referring the
location of objects and their related attributes in an
image. Used as elements of image interpretation.
Site Suitability the determination of the “useful” or
“non-useful” locations based on a set of criteria.
size the physical dimensions (such as length and
width) of objects. An element of image interpretation.
skewed when the unreferenced image is distorted or
slanted during the transformation.
SKP file the file format and extension used by an
object created in Google SketchUp.
SLC the Scan Line Corrector in the ETM+ sensor. Its
failure in 2003 causes Landsat 7 ETM+ imagery to not
contain all data from a scene.
slope a measurement of the rate of elevation change
at a location, found by dividing the vertical height (the
rise) by the horizontal length (the run).
slope aspect a determination of the direction that a
slope is facing.
small-scale map a map with a lower value for its
representative fraction. Such maps will usually show a
large amount of geographic area.
SOS Science on a Sphere, a NOAA initiative used in
projecting images of Earth onto a large sphere.
space segment one of the three segments of GPS,
consisting of the satellites and the signals being
broadcast from space.
spatial analysis examining the characteristics or
features of spatial data, or how features spatially relate
to each other.
spatial query selecting records or objects from one
layer based upon their spatial relationships with other
layers (rather than using attributes).
spatial reference the use of a real-world coordinate
system for identifying locations.
spatial resolution the size of the area on the ground
being represented by one pixel’s worth of energy
measurement.
SPCS the State Plane Coordinate System used for
determining coordinates of locations within the
United States.
SPCS zone one of the divisions of the United States
set up by the SPCS.
spectral reflectance the percentage of the total
incident energy that was reflected from that surface.
spectral resolution the bands and wavelengths
measured by a sensor.
spectral signature a unique identifier for a particular
item, generated by charting the percentage of
reflected energy per wavelength against a value for
that wavelength.
SPOT a satellite program operated by the French
Space Agency and the Spot Image Corporation.
SQL the Structured Query Language—a formal setup
for building queries.
SRTM the Shuttle Radar Topography Mission, flown
in the year 2000, which mapped Earth’s surface from
orbit for the purpose of constructing digital elevation
models of the planet.
Standard Deviation a data classification method
that computes class break values by using the mean
of the data values and the average distance a value is
away from the mean.
standard false color composite an image arranged
by placing the near-infrared band in the red color gun,
the red band in the green color gun, and the green
band in the blue color gun.
StateView the term used to describe each of the
programs affiliated with AmericaView in each state.