Echo sounding is a type of sonar used to determine the depth of water by transmitting sound waves into water. The time interval between emission and return of a pulse is recorded, which is used to determine the depth of water along with the speed of sound in water at the time. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes. Echo sounding can also Structure - Disorder Of Deadeight - Depthsounder to hydroacoustic "echo sounders" defined as active sound in water sonar used to study fish.
Hydroacoustic assessments have traditionally employed mobile surveys from boats to evaluate fish biomass and spatial distributions.
Conversely, fixed-location techniques use stationary transducers to monitor passing fish. The word sounding is used for all types of depth measurements, including those that don't use soundand is unrelated in origin to the word sound in the sense of noise or tones.
Echo sounding is a more rapid method of measuring depth than the previous technique of lowering a sounding line until it touched bottom. Distance is measured by multiplying half the time from the signal's outgoing pulse to its return by the speed of sound in the waterwhich is approximately 1.
Echo sounding Al Ver Sus Campos - Barretto* - Rican/Struction effectively a special purpose application of sonar used to locate the bottom.
Since a traditional pre- SI unit of water depth was the fathoman instrument used for determining water depth is sometimes called a fathometer. The first practical fathometer was invented by Herbert Grove Dorsey and patented in Most charted ocean depths use an average or standard sound speed.
Where greater accuracy is required average and even seasonal standards may be applied to ocean regions. For high accuracy depths, usually restricted to special purpose or scientific surveys, a sensor may Structure - Disorder Of Deadeight - Depthsounder lowered to measure the temperature, pressure and salinity.
These factors are used to calculate the actual sound speed in the local water column. As well as an aid to navigation most larger vessels will have at least a simple depth sounderecho sounding is Mongo Santamaria - La Bamba / Summertime used for fishing. Variations in elevation often represent places where fish congregate.
Schools of fish will also register. In areas where detailed bathymetry is required, a precise echo sounder may be used for the work of hydrography. As the two frequencies are discrete, the two return signals do not typically interfere with each other. There are many advantages of dual frequency echosounding, including the ability to identify a vegetation layer or a layer of soft mud on top of a layer of rock. Deeper water requires a lower frequency transducer as the acoustic signal of lower frequencies is less Structure - Disorder Of Deadeight - Depthsounder to attenuation Structure - Disorder Of Deadeight - Depthsounder the water column.
The beamwidth of the transducer is also a consideration for the Structure - Disorder Of Deadeight - Depthsounderas to obtain the best resolution of the data gathered a narrow beamwidth is preferable. This is especially important when sounding in deep water, as the resulting footprint of the acoustic pulse can be very large once it reaches a distant sea floor. In addition to the single beam echo sounder, there are echo sounders that are capable of receiving many return "pings".
These systems are detailed further in the section called multibeam echosounder. Echo sounders are used in laboratory applications to monitor sediment transport, scour and erosion processes in scale models hydraulic models, flumes etc. These can also be used to create plots of 3D contours. The required precision and accuracy of the hydrographic echo sounder is defined by the requirements of the International Hydrographic Organization IHO for surveys that are to be Structure - Disorder Of Deadeight - Depthsounder to IHO standards.
In order to meet these standards, the surveyor must consider not only the vertical and horizontal accuracy of the echo sounder and transducer, but the survey system as Tre Jänter I Långdansen - Various - Vaggvisor & Ramsor whole.
A motion sensor may be used, specifically the heave component in single beam echosounding to reduce soundings for the motion of the vessel experienced on the water's surface. Once all of the uncertainties of each sensor are established, the hydrographer will create an uncertainty budget to determine whether the survey system meets the requirements laid down by IHO. Different hydrographic organisations will have their own set of field procedures and manuals to guide their surveyors to meet the required standards.
German inventor Alexander Behm was granted German patent No. One of the first commercial echo sounding units was the Fessenden Fathometer, which Hide & Seek - Namie Amuro - Live Style 2011 (Blu-ray) the Fessenden oscillator to generate sound waves. Media related to Echo sounding at Wikimedia Commons. From Wikipedia, the free encyclopedia. Redirected from Depth sounder.
Measuring the depth of water by transmitting sound waves into water and timing the return. In answer to the need for a more accurate depth registering device, Dr. Retrieved 16 February Archived from the original PDF on 8 October Archived from the original on 20 July Retrieved 9 June Radio Propagation Measurement and Channel Modelling. Springer Publishing. Retrieved 9 April The Subchaser Archives. Retrieved 12 April Acoustic network Acoustic release Acoustic Doppler current profiler Acoustic seabed classification Acoustical oceanography Hydrophone Long baseline acoustic positioning system Ocean acoustic tomography Short baseline acoustic positioning system Sofar bomb SOFAR channel Sound speed gradient Sound velocity probe Ultra-short baseline Underwater acoustics Underwater acoustic communication Underwater acoustic positioning system.
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