Adjusting The Gain (Echo Sensitivity) - Simrad ES80 Reference Manual

Simrad ES80 Reference Manual

Adjusting the gain (echo sensitivity)

You can compare this gain setting with the volume control on your car radio. When
the gain is increased, the echoes will appear stronger. Weak echoes will be easier to
see. However, since you also increase the acoustic noise in the reception, the ES80
presentations will also show this noise. Too much gain may therefore "distort" the
presentation.
Context
Comparing the gain function with the volume control on your car radio is not very
accurate. In fact, the gain in the ES80 is constant. The
the sensitivity. This done by controlling the minimum level of detection. When you
increase the gain level (more positive number) , you reduce the minimum level, and thus
increase the sensitivity.
The echo strength (A) changes with time. The minimum level of detection (B) is adjusted
up or down with the
reduces the minimum level, and this increases the sensitivity. Only echoes over the
minimum level are shown in the echogram (C).
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.
Procedure
1 Observe the
Main
Its default location is on the right side of the ES80 presentation.
42
function. Increasing the
Gain
menu.
function is used to adjust
Gain
with a more positive number
Gain
406273/C