Acoustic velocimeter

{
  "id": "MLC-T-MET-003261",
  "term": "Acoustic velocimeter",
  "field": "Meteorology and atmospheric science",
  "definition": "An instrument that measures fluid velocity from sound, either by the Doppler shift of echoes returned by suspended particles or by the difference in travel time of pulses sent in opposite directions. In water, acoustic Doppler velocimeters measure three velocity components in a small sampling volume at tens of hertz, which suits turbulence measurements. In air, sonic anemometers use the travel-time principle.",
  "url": "https://mlchart.com/terminology/meteorology/acoustic-velocimeter/"
}