How To Reject Second-Trace Echoes - Furuno FAR-2218-BB Operator's Manual

1. OPERATIONAL OVERVIEW
1.29

How to Reject Second-trace Echoes

In certain situations, echoes from very distance targets can appear as false echoes
(second-trace echoes) on the screen. This occurs when the return echo is received
one transmission cycle later, or after a next radar pulse has been transmitted.
This equipment lengthens the pulse repetition period to reject false echoes.
Note: This function decreases the number of echo
hits. Use this function carefully so that the possibility
of detecting small targets and high-speed craft does
not lessen.
To reject second trace echoes, do the following:
1. Open the menu.
2. Select [1 ECHO].
3. Select [3 2ND ECHO REJ].
4. Select [ON], then press the ENTER MARK key.
Select [OFF] to disable rejection.
5. Close the menu.
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Pulse
interval
Actual ranges
Measured ranges
Second-trace
echo