{"thcode":2,"term":{"code":2053,"name":"sea-floor acoustic reflectivity","parent":1025,"scope":"Acoustic energy received by a sonar system, providing a measure of the roughness of the sea floor."},"uf":[{"name":"backscatter (sea floor)","usewith":false},{"name":"sea-floor acoustic backscatter","usewith":false}],"bt":[{"code":1025,"name":"sea-floor characteristics","parent":810,"scope":"Geomorphic features and geographic, compositional, and textural variation in the materials composing the ocean floor. Includes both large-scale structures (such as seamounts and rises) and fine-scale variations in rocks and deposits on the sea floor."},{"code":810,"name":"ocean characteristics","parent":287,"scope":"The attributes and process of seas and oceans."},{"code":287,"name":"earth characteristics","parent":1174,"scope":"The measurable, definable properties and features of the earth."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":2037,"name":"interferometric sonar","parent":1083,"scope":"Acoustic technique for determining depths or creating backscatter imagery in a wide swath of seafloor or lakebed centered below the instrument platform."},{"code":2036,"name":"multibeam sonar","parent":1083,"scope":"Acoustic technique for determining depths or creating backscatter imagery in a wide swath of seafloor or lakebed centered below the instrument platform."},{"code":2038,"name":"sidescan sonar","parent":1083,"scope":"Acoustic technique for creating oblique backscatter imagery of the seafloor or lakebed."},{"code":2264,"name":"water column reflectivity","parent":1304,"scope":"A measure of the strength of reflection from small particles suspended in water. It is usually measured by sending a pulse of sound or light through the water and measuring the sound or light that is returned. Water column reflectivity can be used to measure the concentration of suspended particles."}]}