Suppressing Radar Interference; Suppressing Noise Interference; Off Centering The Display - Furuno FMD-811 Operator's Manual

1.16 Suppressing Radar
Interference
Radar interference may occur when near an-
other shipborne radar operating in the same
frequency band as your radar. Its on-screen
appearance is many bright dots either scat-
tered at random or in the form of dotted lines
extending from the center to the edge of the
display. Figure 1-14 illustrates interference
in the form of curved spokes. Interference
effects are distinguishable from normal ech-
oes because they do not appear in the same
place on successive rotations of the scan-
ner.
Figure 1-14 Radar interference
Four levels of interference are available, in-
cluding off: IR1, IR2, IR3 and OFF. IR3
provides the highest level of rejection.
Procedure
1) Press the [MENU] key.
2) Select Int/Noise Rej & ES and press the
[ENT] key.
3) Select INT REJECT.
4) Select level desired; 2 provides the great-
est degree of interference rejection
4) Press [ENT] and [MENU].
IR and level selected appear at the top right
corner on the display when the interference
rejection circuit is turned on.
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1.17 Suppressing Noise
Interference
Noise interference appears on the screen as
many bright dots. These dots can be sup-
pressed by turning on the noise rejector. Note
however that there are some forms of noise
interference which the unit cannot suppress.
Procedure
1) Press the [MENU] key.
2) Select Int/Noise Rej & ES and press the
[ENT] key.
3) Select Noise Reject to ON.
4) Press the [ENT] key followed by the
[MENU] key.

1.18 Off Centering the Display

Your vessel's position can be shifted any-
where within 75% of the effective display
area. The primary advantage of the off cen-
tered display is that for any range setting,
the view ahead of your vessel can be ex-
tended without changing the range or size
of targets.
Procedure
1) Locate the cursor where you want the
screen center to be.
2) Press the [OFF CENTER] key.
OFF CENTER appears at the top left corner
on the display when the display is off cen-
tered.
Note: The off centered display is automatically
canceled when the [DISP MODE] key is
pressed and the range is 64 or 72NM.