Simrad NSO Operation Manual page 49

Normally range is controlled by the IN and OUT Keys, you can swap these keys to enable
them to adjust zoom by ticking 'Swap range/zoom controls in the System, Settings,
Advanced Echo menu.
UPPER LIMIT IS 30 FEET
LOWER LIMIT IS 50 FEET
The echosounder panel can be setup as a single view, or with split view where the left
and the right side presents different images.
Split screen options
Zoom
The Zoom mode presents a magnified view of the
sounder image on the left side of the panel.
By default the zoom level is set to 2x. You can
select up to 8x zoom from the drop-down menu.
The range zoom bars on the right side of the
display shows the range that is magnified. If you
increase the zooming factor the range will be
reduced. You will see this as reduced distance
between the zoom bars.
Zoom bars
Bottom lock
The bottom lock mode is useful when you want to
view echoes close to the bottom.
In this mode the left side of the panel shows an
image where the bottom is flattened. The range
scale is changed to measure from the seabed (0)
and upwards. The bottom and the zero line will
always be shown on the left image, independent
on range scale.
The scaling factor for the image on the left side
of the panel is adjusted as described for the
Zoom option.
Echo frequency
The NSO unit supports several transducer
frequencies. Available frequencies depend on
sounder module and which transducer model is
connected.
You can view two frequencies at the same time
by setting up a dual echosounder
Noise rejection
Signal interference from bilge pumps, engine vibration and air bubbles can clutter the
image. The noise rejection option filters the signal interference and reduces the on-
screen clutter.
48 | Using echosounder