NorthStar Navigation Multi-Function Unit M84 - Manual (Page 45)

Northstar M121/M84 Installation and Operation Manual 44
10-3 Sonar Bottom window
The window shows the sonar history on the
right and the bottom signal as a flat trace in
the centre of the zoom section on the left. The
flat trace make it easy to compare the echo
strengths shown in the bottom signals. This can
help to identify the type of bottom and objects
close to the bottom.
The zoom bar on the far right shows the area
of the history that is magnified in the zoom
section:
• Use the or keys to adjust the zoom
range.
• The Instrument calculates the zoom depth
automatically.
It is not necessary to turn Bottom lock on for
this window.
A Zoomed bottom signal
B Sonar history
10-4 Sonar 50/200 window
The window shows:
A the 50 kHz sonar history on the left
B the 200 kHz sonar history on the right.
Gain can be set independently for each
frequency (see section 9-6). Range applies to
both frequencies (see section 9-5).
B
A
A B