7. AIS OPERATION
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7.14 AIS System Messages
AIS system messages are displayed at the bottom right corner of the screen.
The table below shows the AIS system messages and their meanings.
AIS system messages
Message Meaning
ARPA FUSION
ARPA target converted to AIS target. The indication
disappears when the target no longer meets the
criteria set in paragraph 7.13. When the message
RECEIVE is displayed, ARPA FUSION is not
displayed.
COLLISION
CPA/TCPA of an AIS target is below preset value.
LOST Lost
target
RECEIVE
Not receiving AIS data
WT
This message appears when the water tracking
mode is set at the radar and the data necessary for
STW and CSE are not available. In this case the
vector on the AIS symbol does not appear and SOG
(speed over ground) and COG (course over ground)
are displayed on the basic display.
GUARD
Displayed when a target enters the ARPA guard
ring.
CPA/TCPA
CPA/TCPA cannot be calculated because the “WT”
alarm has been violated. Further the CPA/TCPA
value in basic data display is marked with an
asterisk to indicate that CPA/TCPA value is not
reliable.
FULL
Displayed when 1000 AIS targets have been
received. (The radar can only display 1000 AIS
targets closest in range to own ship.)
