https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.8 2026-04-29T10:52:37.449Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/instruments/eb8fdbae-05fc-4017-9759-300261552f45 IES Inverted Echo Sounders (IES) measure the temperature of thewater column at a single point. The IES is attached to the oceanbottom. It emits a sound pulse aimed toward the surface of theocean. The sound pulse will reflect off the surface of the oceanand return to the bottom. The IES listens for the return of thesound pulse from the ocean surface. The travel time of the soundis used to calculate the speed of sound through the water. Thetemperature profile is calculated from the speed of soundthrough the water. The IES must be calibrated with a measurementof the water column properties. Sometimes a pressure sensor isused with the IES to make the calibration.Additional information available at'http://omp.gso.uri.edu/dosits/people/resrchxp/1.htm'[Summary provided by University of Rhode Island]