Hydroacoustics, or the study and application of sound waves in water, is of great significance to our ability to understand the worlds oceans, lakes and river systems. In much the same way that dolphins are able to emit sounds and percieve the echoes that return, we can transmit sounds and listen to the echoes closely using echosounders. From the resulting echoes we're able to estimate:
- The range of a reflector, like a fish, or the sea floor from the transceiver by observing the round trip time of a ping between transmission and reception. A common application is detecting water depth (bathymetry).
- The size of a reflector, like a fish or school of fish, by observing the strength and spread of the returned ping signals.
- The behaviour of fish, by observing over time, their position and schooling behaviours.
- Biomass, or the quantity of fish in a region through planned surveys using hydroacoustic instruments.
- The properties of the sea floor, including vegatation, hardness and roughess, by observing various properties of the returned echoes.
- The motion of water and other objects by observing frequency shifts (the Doppler effect) in the reflected echoes.
We have a long way to go before we match the abilities of a dolphin to appraise the underwater environment using sound, but the science progresses steadily all the same.
Integral to all of these applications is the rigorous kind of analysis of echoes that Echoview offers, contributing to its extreme popularity among hydoacoustics professionals.
Some further reading on hydroacoustics:
- HTI (Hydroacoustic Technology Inc.)
- The U.S. Geological Survey Office of Surface Water
- Fisheries acoustics