Ais Operation - Furuno FCR-2107 Series Operator's Manual

5. AIS Operation

An AIS transponder can be connected to the Chart Radar to display AIS targets received from the AIS transponder.
The Chart Radar can store up to 1,500 AIS targets in its storage buffer. When this buffer becomes full of AIS
targets, the Alert 639 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 Ground (SOG), Course Over Ground (COG),
Rate Of Turn (ROT) and heading. 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.
Chart Radar can display AIS targets which are within the operator-defined range (max. range is 48 nm). The
maximum number of targets which can be displayed is 240 and the operator may choose the number of targets to
display. Alert 637 is generated when there are more than the operator-specified amount of AIS targets within the
operator-chosen range.
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 Chart
Radar defines which AIS targets are in tracking, lost or deleted. When you acknowledge a lost target alert, AIS
symbol will be removed from the ECDIS display. If lost target is not acknowledged, automatic removal of AIS
symbol is done as shown table below.
Type of Ship
Class A: speed between 0-14 kn
Class A: speed between 14-23 kn
Class A: speed greater than 23 kn
Class A: anchored, moored, not under control or grounded,
speed between 0-3 kn
Class A: anchored, moored, not under control or grounded,
speed greater than 3 kn
Class B: CS speed between 0-2 kn
Class B: CS speed greater than 2 kn
Class B: SOTDMA speed between 0-2 kn
Class B: SOTDMA speed between 2-14 kn
Class B: SOTDMA speed between 14-23 kn
Class B: SOTDMA speed greater than 23 kn
Class A and Class B: no speed available
ATON
SAR
Base station
SART
An AIS transponder "sees" all ships fitted with an AIS transponder belonging to either
•
Class A AIS
•
Class B AIS
Additionally the AIS transponder receives messages from ships and these non-ships:
•
AIS Base station
•
AIS on airborne SAR craft
•
AIS on ATON (AIS aid to navigation)
There can be several hundreds or several thousands of AIS targets, and of those only a few will be significant for
your ship. To remove unnecessary AIS targets from the Chart Radar display, the feature "active and sleeping AIS
targets" is available. Initially any new AIS target received by an AIS transponder is not active (="sleeping"). Such
non-active targets are shown with a small triangle. User can pick any AIS target and change it from non-active to
IMO nominal Lost target
reporting indication
interval (reporting
interval >)
10 s 50 s
6 s 30 s
2 s 10 s
3 min 10 min
10 s 50 s
3 min 10 min
30 s 150 s
3 min 10 min
30 s 150 s
15 s 75 s
5 s 25 s
N/A 10 min
3 min 10 min
10 s 50 s
10 s 50 s
N/A 18 min
Pre-set rate
for automatic
removal of
lost target
430 s
430 s
430 s
36 min
36 min
36 min
430 s
36 min
430 s
430 s
430 s
36 min
30 min
430 s
430 s
30 min
5-1