Ais Operation - Furuno FAR-2228-BB Operator's Manual

4.

AIS OPERATION

An AIS transponder can be connected to this radar to overlay AIS targets on the radar
display. The radar can store up to 1,200 AIS targets in its storage buffer. When this
buffer becomes full of AIS targets, the Alert "AIS CAPACITY FULL" is generated to
alert you to full storage buffer. The storage buffer contains automatic dead reckoning
for all AIS targets, which is based on reported Speed Over the Ground (SOG) and
Course Over the Ground (COG). The storage buffer also contains calculation of range,
bearing, CPA, TCPA, etc. The CPA and TCPA limits set for dangerous targets are
common for TT and AIS targets.
This radar can activate 50 AIS targets. The Alert "ACTIVE AIS FULL" is generated
when 50 AIS targets are activated.
This radar can display a maximum of 350 AIS targets. The Alert "AIS DISPLAY FULL"
is generated when 350 AIS targets, which includes both activated and sleeping tar-
gets, are displayed.
The frequency for update of AIS transponder-sent data depends on speed and course
of tracked AIS target. The table below shows the IMO standardized reporting rates for
the AIS transponder. Based on the table below, the radar defines which AIS targets
are in tracking or lost. When you acknowledge a lost target alert, the corresponding
AIS symbol will be removed from the display.
Class A: Navigation status is "anchor" or "not under
command" or "moored" or "aground", and SOG
Class A: Navigation status is "anchor" or "not under
command" or "moored" or "aground", and SOG > 3kn
Class A: 0kn
Class A: 14kn
Class A: SOG > 23kn
Class B: "CS" SOG
Class B: "CS" SOG > 2kn
Class B: "SO" 0 kn
Class B: "SO" 2 kn < SOG < 14kn
Class B: "SO" 14 kn
Class B: "SO" SOG > 23kn
Class A and Class B: no SOG available
AIS SAR aircraft
AIS aid to navigation
AIS base station
AIS search and rescue transponder
An AIS transponder "sees" all ships fitted with an AIS transponder belonging to either
a Class A or Class B AIS. Additionally, the AIS transponder receives messages from
ships and non-ships (AIS SAR aircraft, AIS aid to navigation, AIS base station, and
AIS search and rescue transmitter).
Type of Ship
SOG < 14kn
SOG 23kn
2kn
SOG 2kn
SOG 23kn
IMO
nominal
reporting
interval
3 min
3kn
10 s
10 s
6 s
2 s
3 min
30 s
3 min
30 s
15 s
5 s
N/A
10 s
3 min
10 s
N/A
Lost target
indication
(reporting
interval >)
10 min
50 s
50 s
30 s
10 s
10 min
150 s
10 min
150 s
75 s
25 s
10 min
50 s
10 min
50 s
10 min
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