Noise filter, Surface clutter filter, Pulse length – NorthStar Navigation Multi-Function Unit M84 User Manual
Page 77: Pulse power, 4 setup > radar, Rotation
Northstar M121/M84 Installation and Operation Manual
76
Noise filter
Averages the echo signal to remove rapid
changes. Select Medium or High to give a
smoother bottom trace–this may help to detect
a deeper bottom; however these settings may
also remove fish echoes. Select Off for best
fishfinding.
Surface clutter filter
Use this filter to hide the surface noise. Any
significant echoes (such as fish) will still be
displayed.
Pulse length
This can be used to specify the length of
the transmitted ultrasonic pulse. A short
pulse length improves the window detail but
contains less energy, therefore it does not
penetrate as deeply into the water as a longer
pulse.
There is a choice of Auto, Short, Medium
or Long. The Auto setting is recommended.
Pulse power
This can be used to specify the power output
of the transmitted ultrasonic pulse. Low power
output conserves the battery and produces a
clear display in shallow water.
There is a choice of Auto, Low, Medium or
High. The Auto setting is recommended.
19-4 Setup > Radar
Note: This option is shown only when the radar
is enabled (see Section 18-3)
1 Press MENU twice to display the Setup
menu, then select Radar:
Rotation
The current radar rotation is shown in the top
left corner of the radar screen. If COG data or
heading data is not available from a compass,
the radar rotation is automatically set to Head
up.
However, you are strongly recommended to
use a good quality product (such as a Northstar
HS02, HS03 or Autopilot) to provide heading
data.
If heading data is available from a compass, the
options are:
• North up works only when COG data or
heading data from a heading sensor is
available. North is always at the top of the
radar screen.
You can easily compare the radar screen to a
chart in North up.
• Head up means that the radar image rotates
underneath your boat, so the direction in
which you are heading is pointing to the top
of the radar screen. You can easily compare
the visual view in front of your boat with the
radar screen.