Humminbird 515 - Manual (Page 14)

9
Understanding Sonar History
It is important to understand the significance of
the 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).
The Narrow RTS® Window
indicates the sonar
intensity through the use of
grayscale. The grayscale
used matches the bottom
view grayscale setting
used in the sonar history
window (i.e. Inverse,
Structure ID®, WhiteLine®,
Bottom Black). 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. The
Wide RTS® Window does not
make use of grayscale.