EM 1110-2-2907
1 October 2003
Thermal inertia (P)
Measure of the response of a material to temperature changes,
expressed in calories per square centimeter per square root of second.
Thermal IR
IR region from 3 to 14 m that is employed in remote sensing. This
spectral region spans the radiant power peak of the earth.
Thermal IR image
Image acquired by a scanner that records radiation within the thermal
IR band.
Thermal IR multispectral
Airborne scanner that acquires multispectral images within the 8-to-
scanner (TIMS)
14mm band of the thermal IR region.
Thermal model
Mathematical expression that relates thermal and other physical
properties of a material to its temperature. Models may be used to
predict temperature for given properties and conditions.
Thermography
Medical applications of thermal IR images. Images of the body, called
thermograms, have been used to detect tumors and monitor blood
circulation.
THIR
Temperature-Humidity Infrared Radiometer, carried by Nimbus-7.
Tie-point
A point on the ground, which is common to two images. Several are
used in the co-registration of images.
TIMS
Thermal IR multispectral scanner.
TM
Thematic Mapper.
Tone
Each distinguishable shade of gray from white to black on an image.
Topographic inversion
An optical illusion that may occur on images with extensive shades.
Ridges appear to be valleys, and valleys appear to be ridges. The
illusion is corrected by orienting the image so that the shadows trend
from the margin of the image to the bottom.
Topographic reversal
A geomorphic phenomenon in which topographic lows coincide with
structural highs and vice versa. Valleys are eroded on crests of
anticlines to cause topographic lows, and synclines form ridge, or
topographic highs.
TOVS
TIROS Operational Vertical Sounder.
Tracking and Data Relay
Geostationary satellite used to communicate between ground receiving
Satellite (TDRS)
stations and satellite such as Landsat.
Training area
A sample of the Earth's surface with known properties; the statistics of
the imaged data within the area are used to determine decision
boundaries in classification.
Trade-off
As a result of changing one factor in a remote sensing system, there
are compensating changes elsewhere in the system; such a
compensating change is known as a trade-off.
Training site
Area of terrain with known properties or characteristics that is used in
supervised classification.
Transmissivity
Property of a material that determines the amount of energy that can
pass through the material.
Transparency
Image on a transparent photographic material, normally a positive
image.
Transpiration
Expulsion of water vapor and oxygen by vegetation.
Travel time
In radar, the time interval between the generation of a pulse of
microwave energy and its return from the terrain.
Tristimulus color theory
A theory of color relating all hues to the combined effects of three
additive primary colors corresponding to the sensitivities of the three
types of cone on the retina.
U
Unsupervised
Digital information extraction technique in which the computer assigns
classification
pixels to categories with no instructions from the operator.
Glossary-29
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