JRC JMA-9932-SA - Page 216

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Side
Lobe
Effect
A broken-line circular arc
may appear at
the same
range as
the main lobe
of the radar
beam
on
the
radar
display.
This type
of
false echo
can
easily be discriminated
when
a
target
echo
appears
independent.
(See
Fig.
6.3)
Fig. 6.3
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False
Echo
by Secondary
Reflection
When
a
target exists
near own
ship,
two echoes
from the single target may appear
on
the
radar
display. One of
those echoes is the direct
echo
return
from
the target and the other is the
secondary
reflection
return from
a mast or
funnel that stands
in the same direction
as shown
in
Fig.
6.4.
target
Radar
scanner
l\
False
echo from
funnel
Funnel
Secondary reflection
of micro wave
Fig. 6.4
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False
Echo
by Multiple
Reflection
When there is a
large structure or ship
with a
high vertical
surface
near
own
ship as shown
in Fig.
6.5, multiple
reflection returns may appear
on the
radar
display.
These echoes appear
in
the
same intervals,
of
which the nearest
echo
is the
true echo
of
the target.
Fig.6.5
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