<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="981" name="remote sensing" parent="734" scope="Acquiring information about a natural feature or phenomenon, such as the Earth's surface, without actually being in contact with it. USGS remote sensing is usually carried out with airborne or spaceborne sensors or cameras."/><uf><usefor name="airborne imaging"/><usefor name="composite burn index"><usewith><term thcode="2" code="1378" name="fire damage" parent="522" scope="Destruction of surficial materials and vegetation by burning."/></usewith></usefor><usefor name="normalized burn ratio"><usewith><term thcode="2" code="1378" name="fire damage" parent="522" scope="Destruction of surficial materials and vegetation by burning."/></usewith></usefor><usefor name="photogrammetry"/><usefor name="remote-sensing data"><usewith><term thcode="2" code="575" name="image collections" parent="808" scope="Visible representations of objects or earth properties produced by cameras, spectral instruments, or as graphical representations of measurements."/></usewith></usefor><usefor name="remote-sensing images"><usewith><term thcode="2" code="575" name="image collections" parent="808" scope="Visible representations of objects or earth properties produced by cameras, spectral instruments, or as graphical representations of measurements."/></usewith></usefor><usefor name="satellite altimetry"><usewith><term thcode="2" code="36" name="altimetry measurement" parent="450" scope="The measurement of altitude, or height above mean sea level, using instruments such as aneroid barometers and radar altimeters."/></usewith></usefor><usefor name="satellite images"><usewith><term thcode="2" code="575" name="image collections" parent="808" scope="Visible representations of objects or earth properties produced by cameras, spectral instruments, or as graphical representations of measurements."/></usewith></usefor><usefor name="satellite imaging"/><usefor name="space-borne sensing"/></uf><bt><term thcode="2" code="734" name="methods" parent="1" scope="Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><nt><term thcode="2" code="571" name="IFSAR" parent="981" scope="Interferometric comparison of radar reflectance imagery of the same area at different times to determine changes in the land surface, typically from a space-borne sensor."/><term thcode="2" code="15" name="aerial photography" parent="981" scope="The process of taking pictures with a camera from an aircraft. Use for both the process of photography from the air and the images produced by the process."/><term thcode="2" code="18" name="aeromagnetic surveying" parent="981" scope="Mapping of the earth's magnetic field with the use of airborne electronic magnetometers."/><term thcode="2" code="19" name="aeroradiometric surveying" parent="981" scope="Mapping of gamma radiation from the earth's surface with airborne scintillation meters or gamma-ray spectrometers."/><term thcode="2" code="563" name="hyperspectral imaging" parent="981" scope="Multispectral imaging technique that records many bands of imagery at very narrow bandwidths."/><term thcode="2" code="588" name="infrared imaging" parent="981" scope="Method of remote sensing in which optical sensors produce visible representations of infrared rays or radiated heat from the observed objects and the temperature variations are represented by different colors in the image."/><term thcode="2" code="648" name="lidar" parent="981" scope="Light detection and ranging, an airborne, spaceborne or ground-based laser-ranging technique commonly used for acquiring high-resolution topographic data."/><term thcode="2" code="742" name="microwave imaging" parent="981" scope="Remote sensing method using short high frequency electromagnetic waves reflected or radiated from the ground."/><term thcode="2" code="765" name="multispectral imaging" parent="981" scope="A method of remote sensing that obtains optical representations in two or more ranges of frequencies or wave lengths."/><term thcode="2" code="867" name="panchromatic imaging" parent="981" scope="Photographic technique which uses emulsions, films, or plates sensitive to all colors in light to produce black-and-white photographs. Often used in aerial and satellite photography."/><term thcode="2" code="948" name="radar imaging" parent="981" scope="A remote sensing technique which uses the reflection of pulsed high frequency radio waves to determine the speed, direction, and distance of faraway objects."/><term thcode="2" code="1161" name="thermal imaging" parent="981" scope="Remote sensing techniques using instruments to measure emitted thermal radiation to form images of the earth's surface."/><term thcode="2" code="1281" name="visible light imaging" parent="981" scope="Remote sensing methods using electromagnetic radiation which is visible to the human eye to react with the coating on a photographic plate or film."/></nt><rt><term thcode="2" code="447" name="geography" parent="291" scope="Study of the earth's landforms, topography, and climate, the distribution of flora and fauna, and the distribution, culture, and activities of human populations."/><term thcode="2" code="2291" name="gravity gradient" parent="501" scope="Lateral variation of the three-dimensional vector components of gravity, typically measured using airborne sensors."/><term thcode="2" code="1042" name="seismic methods" parent="375" scope="Procedures used to record and study earthquakes or earth vibrations including those that are artificially induced."/><term thcode="2" code="2265" name="structure from motion" parent="574" scope="Mathematical analysis, using photogrammetric principles, of multiple images that depict the same subject from different angles to derive geometrical information and relationships in three-dimensional space that are not inherent in any single image. Often used for deriving land elevation or large scale orthoimagery from a collection of aerial photographs."/><term thcode="2" code="1148" name="telemetry" parent="375" scope="Field technique using instruments which measure heat, radiation, speed, or other property and transmit the data to a distant receiver."/><term thcode="2" code="1276" name="videography" parent="734" scope="The process of recording and editing analog or digital video."/></rt></descriptor>