USING THE 128 SERIES
WHAT YOU SEE ON SCREEN
6
absorbed by the soft bottom. If the
bottom is rocky or rugged in
composition, the depiction is of
varying density and textured in
appearance.
Wave action also affects the bottom
depiction. The information drawn is
a distance measurement, so if the
boat is moving up and down over
flat bottom, the bottom depiction
often appears in regular variations
that match wave timing.
S
TRUCTURE
.
Structure is defined as
any object physically attached to the
bottom. The sonar configuration of
the
128
is optimized to give the most accurate depiction of bottom
structure possible. Grass, trees, stumps, wrecks or other debris are
accurately displayed, however the depiction of these objects varies with
boat speed and direction. The best way to learn to interpret structure is
to operate the
128
over a variety of known conditions and experiment
with the user functions GAIN and
the Chart Speed and FILTER Control
Panels to best represent those
conditions on-screen.
S
URFACE
C
LUTTER
.
Surface clutter is
the layer of water near the surface
that is rich in algae and other
growth, and often is aerated by
wind or wave action. This area of
water interferes with sonar
transmission and often appears
on-screen as regular clusters of ind-
ividual dots near the “0” line.
Thermocline Second Return
Surface clutter Structure
Summary of Contents for TFX128
Page 1: ...TFX1 28 Operations Manual...
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