Understanding Sonar History
It is important to understand the significance of the 900 Series™ display. The
display does NOT show a literal 3-dimensional representation of what is
under the water. Each vertical band of data received by the control head and
plotted on the display represents something that was detected by a sonar
return at a particular time. As both the boat and the targets (fish) may be
moving, the returns are only showing a particular segment of time when
objects were detected, not exactly where those objects are in relation to
other objects shown on the display.
Real Time Sonar (RTS®) Window
A Real Time Sonar (RTS®) Window appears on the right side of the display in
the Sonar View only. The RTS® Window always updates at the fastest rate
possible for depth conditions and shows only the returns from the bottom,
structure and fish that are within the transducer beam. The RTS® Window plots
the depth and intensity of a sonar return. (See
Sonar Menu: RTS® Window
).
Bottom Presentation
As the boat moves, the unit charts the changes in depth on the display to
create a profile of the
Bottom Contour
. The type of bottom can be
determined from the return charted on the display. A
Hard Bottom
such as
compacted sediment or flat rock appears as a thinner line across the display.
A
Soft Bottom
such as mud or sand appears as a thicker line across the
display.
Rocky Bottoms
have a broken, random appearance.
NOTE:
A sloping bottom will be represented as a thicker line across the display.
Harder bottoms typically will be displayed with red and softer bottoms typically
will be displayed with blue.
The sonar returns from the bottom, structure and fish can be represented as
either
Structure ID®
or
WhiteLine®
. See
Sonar Menu: Bottom View
for
details on how to set the bottom view.
Structure ID®
represents weak returns in blue and strong returns in red.
The
Narrow RTS® Window
indicates the sonar intensity
through the use of colors.
Red indicates a strong return
and blue indicates a weak
return. The depth of the
sonar return is indicated by
the vertical placement of the
return on the display depth
scale.
The
Wide RTS® Window
indicates the sonar intensity
through the use of a bar
graph.
The length of the
plotted return provides an
indication of whether the
return is weak or strong. The
depth of the sonar return is
indicated by the vertical
placement of the return on
the display depth scale.
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