Radar MARINE RADAR/ARPA Operator's Manual

4. AIS OPERATION
4-23
4.15 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 merged with AIS target. The indication
disappears when the target no longer meets the criteria
set in paragraph 4.12. When the message “RECEIVE”
is displayed, ARPA FUSION is not displayed.
COLLISION CPA and TCPA of an activated AIS target are below
value set on the menu.
TARGET-FULL Displayed when 1000 AIS targets have been received.
(The radar can only display 1000 AIS targets closest in
range to own ship.)
LOST Lost target. A target is declared a lost target when a
dangerous target fails to produce data for six minutes or
five reporting intervals, whichever is the shorter.
RECEIVE Not receiving AIS data from own AIS (VDO message).
GUARD Displayed when an AIS target enters the guard zone.
CPA/TCPA CPA/TCPA cannot be calculated. Further the CPA/TCPA
value in the basic data display is marked with an
asterisk to indicate that it is not reliable.
AIS ALARM Alarm received from AIS transponder.
AIS CPA alarm
The CPA alarm (see page 3-22) is also released against stationary AIS targets.
An AIS target is judged to be a stationary target if its speed is lower than a
certain speed. For AIS targets you can elect to get only the visual alarm, as
follows:
1. Left-click the MENU box.
2. Choose 4 [ARP·AIS] and push the wheel.
3. Choose 0 AIS CPA ALM and push the wheel.
4. Choose IGNORE TARGET and push the wheel.
5. Set speed to ignore AIS targets below this threshold.
6. Push the right button three times to close the menu.