JRC JMA-9922-6XA Instruction Manual page 220

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[II] 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.
appears independent. (See Fig. 6.3)
[III] 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.
Direct micro wave
Radar scanner
Funnel
[IV] 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.
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This type of false echo can easily be discriminated when a target echo
Fig. 6.3
Secondary reflection
of micro wave
Fig. 6.4
Fig. 6.5
6-4
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HL
HL
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Actual target
False echo from
funnel
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