4-1
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.
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
IMO
nominal
reporting
interval
Lost target
indication
(reporting
interval >)
Class A: Navigation status is “anchor” or “not under
command” or “moored” or “aground”, and SOG
d
3kn
3 min
10 min
Class A: Navigation status is “anchor” or “not under
command” or “moored” or “aground”, and SOG > 3kn
10 s
50 s
Class A: 0kn
d
SOG < 14kn
10 s
50 s
Class A: 14kn
d
SOG
d
23kn
6 s
30 s
Class A: SOG > 23kn
2 s
10 s
Class B: “CS” SOG
d
2kn
3 min
10 min
Class B: “CS” SOG > 2kn
30 s
150 s
Class B: “SO” 0 kn
d
SOG
d
2kn
3 min
10 min
Class B: “SO” 2 kn < SOG < 14kn
30 s
150 s
Class B: “SO” 14 kn
d
SOG
d
23kn
15 s
75 s
Class B: “SO” SOG > 23kn
5 s
25 s
Class A and Class B: no SOG available
N/A
10 min
AIS SAR aircraft
10 s
50 s
AIS aid to navigation
3 min
10 min
AIS base station
10 s
50 s
AIS search and rescue transponder
N/A
10 min
Summary of Contents for FAR-2218
Page 132: ...1 OPERATIONAL OVERVIEW 1 110 This page is intentionally left blank ...
Page 176: ...3 TARGET TRACKING TT 3 36 This page is intentionally left blank ...
Page 202: ...4 AIS OPERATION 4 26 This page is intentionally left blank ...
Page 232: ...5 VIDEO PLOTTER OPERATION 5 30 This page is intentionally left blank ...
Page 294: ......