Acoustic Noise; Contributing Factors - Simrad ES80 Reference Manual

Simrad ES80 Reference Manual

Acoustic noise

As with any other hydroacoustic systems, the quality of the ES80 echo data and
presentations are subject to unwanted acoustic noise. The echoes from any large and
small target must be detected inside the noise.
Topics
Contributing factors, page 462
Self noise, page 464
Ambient noise, page 466
Fishing gear noise, page 467
Electrical self noise, page 467
Some means to reduce acoustic noise, page 467

Contributing factors

Several factors are contributing to the performance of the hydroacoustic equipment
used on board a vessel.
Factors contributing to the performance of the hydroacoustic equipment used on board a
vessel are:
• The quality and properties of the transmitted signal
• The quality of the receiving system
• The operational settings made during operation
• The properties of the target(s)
• The signal-to-noise ratio
The majority of these factors can neither be controlled nor improved by means
of installation methods or transducer locations. The quality and properties of the
transmitting and receiving systems are key factors during our product development, while
our end user documentation aims to help the user to make the right filter settings during
operation. As for the target properties, there is nothing any of us can do with those.
The signal-to-noise ratio, however, can be improved by making the correct choices
during installation.
Signal-to-noise ratio (often abbreviated SNR or S/N) is a measure used in
science and engineering that compares the level of a desired signal to the level of
background noise. It is defined as the ratio of signal power to the noise power, often
expressed in decibels. A ratio higher than 1:1 (greater than 0 dB) indicates more
signal than noise. While SNR is commonly quoted for electrical signals, it can
be applied to any form of signal [...].
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