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Sound Velocity Probe
A sound velocity probe is a device that is used for measuring the speed of sound, specifically in the water column, for oceanographic and hydrographic research purposes. History Early depth sounding was achieved using lead line sounding (or sounding line), where a lead weight attached to a length of rope marked with depth values. As this method was mechanical in nature, the only correction that was applied to the sounding was the reduction of the sounding for tidal height. In the mid 20th century, sonar systems were developed to allow the measurement of underwater distances using the two way travel time of an acoustic pulse. This allowed the surveyor to take many more soundings in a given period of time and was less labor intensive than using a lead line. Use For many applications of sonar the speed of sound can be assumed to be an average speed of 1500 meters per second. However, the speed of sound in seawater can vary from 1440 to 1570 meters per second., UN Atlas of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sounding Line
Depth sounding, often simply called sounding, is measuring the depth of a body of water. Data taken from soundings are used in bathymetry to make maps of the floor of a body of water, such as the seabed topography. Soundings were traditionally shown on nautical charts in fathoms and feet. The National Oceanic and Atmospheric Administration (NOAA), the agency responsible for bathymetric data in the United States, still uses fathoms and feet on nautical charts. In other countries, the International System of Units (metres) has become the standard for measuring depth. Terminology "Sounding" derives from the Old English ''sund'', meaning "swimming, water, sea"; it is not related to the word ''sound'' in the sense of noise or tones, but to ''sound'', a geographical term. Traditional terms for soundings are a source for common expressions in the English language, notably "deep six" (a sounding of 6 fathoms). On the Mississippi River in the 1850s, the leadsmen also used old-fashione ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
