Simrad ES80 Reference Manual page 438

Simrad ES80 Reference Manual
The dynamic range
The ES80 has a dynamic range of
140 dB. This means that the ES80
can receive both very strong and very
weak echoes. Actually, the ES80 will
detect echoes from plankton to whales,
bottom on most depths, and present the
information free from distortion. As a
comparison, our old echo sounders
ES380 and ET100 had - using analogue
TVG - a dynamic range corresponding
to approximately 65 dB.
Naturally, we can not present all these
echoes on the display simultaneously, as
this would create a mess of colours.
When 12 colours are used, we create a 36 dB total range, and let each colour present a 3
dB strength. Every colour (3 dB) the represent a doubling of the echo strength. With 12
colours in use this will be a 36 dB colour range from grey to brown. Grey is used for the
weakest echoes, while the strongest echoes are brown. All echoes stronger than brown
will still be brown, while echoes weaker than grey will not be shown.
With 64 colours in use, each colour represents approximately 0.5 dB echo strength.
The old paper sounders had a dynamic range of 12 dB in their printouts using the
"colours" from light grey to black. The dynamic range in the ES80 colour presentation
is thus a lot larger; 24 dB or 250 times. Along this dynamic range we take the 36 dB
range and "move it" up and down.
Note
Your choice of colour scale has no effect on the gain settings. The colour scale only
controls the visual presentation of the ES80 echo data.
Colour Setup
The dialog box allows you to choose from several colour scales to use in
Colour Setup
the ES80 echo presentations. Which colour scale to use is mainly a personal preference
based on ambient light conditions, the nature of the echoes and your own experience.
The following colour scales are available.
12 colours Sonar colours
The
Smooth Echosounder
colours have been added between them to make smoother colour transitions.
436
Smooth ES
scale is based on the standard 12-colour scale. Additional
Grayscale BI500 colours
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