Simrad NX40 Installation & Operation Manual page 83

desired heading is always pointing to
the top of the radar screen so that
you can compare the leg bearing
of the active route with the radar
screen. (If you're in Course up
rotation but don't have an active
route, the radar uses Head up
rotation until a route is made active.)
Motion mode True motion mode is not available
if there is no position data, and no
heading or COG data.
There are two choices:
Relative (RM). Your boat remains in
a fixed location on the radar screen
and all other objects move relative
to your position. (You can choose the
position of the fixed location). RM is
the default.
True (TM)
targets, move across the radar
screen as you travel. All stationary
objects remain in a fixed position.
You must have position data, and
heading or COG data for this option
to be available.
Interference filter
is operating at the same frequency as
your radar, it can cause interference
patterns on the radar window.
Interference patterns always appear
in a different place with each sweep.
They can be randomly scattered
bright dots or dotted lines that
extend from the center to the edge of
the radar window, often producing a
spiral pattern. Generally, the stronger
the interference, the wider the
interference lines.
Use the interference rejection option
to reduce both the interference
patterns and the width of the
interference lines.
There are four choices:
Off. Interference rejection is off.
Low operates the interference
rejection at minimum strength.
Medium operates the interference
rejection at medium strength.
High operates the interference
rejection at maximum strength. This
setting can make it more difficult
to detect some targets and radar
. Your boat, and moving
If the radar on another boat
Simrad NX40/45 Installation and Operation Manual 83