Stabilization In True Motion; Lost Target; How To Set The Lost Target Filter - Furuno FAR-2228-BB Operator's Manual

4. AIS OPERATION
4.11.4

Stabilization in true motion

True motion past position display can be ground stabilized or sea stabilized. The
[TRAIL] box shows current stabilization as "TRUE-G" or "TRUE-S". To change stabi-
lization mode, open the [SHIP SPEED MENU] menu and set [SHIP SPEED] to
[LOG(BT)] (ground stabilization) or [LOG(WT)] (sea stabilization).
4.12

Lost Target

A target is declared a lost target when it fails to produce data for six minutes or five
reporting intervals, whichever is the shorter. When this occurs, the target is marked
with the (flashing) lost target symbol and the message "AIS TARGET LOST" appears
in the Alert Box. To acknowledge a lost target, press the ALARM ACK key, or use the
trackball to select the [ALERT] box then press the left button.
4.12.1

How to set the lost target filter

If there are a lot of AIS targets in your area, the lost target alert can sound frequently.
In this case you may wish to have the alert ignore lost targets whose range, speed,
class or length are below the threshold value you specify.
1. Open the menu.
2. Select [5 TT•AIS].
3. Select [5 AIS].
4. Select [0 NEXT].
5. Select [3 AIS LOST TGT FILTER].
6. Referring to the following table, select the appropri-
ate filter.
[MAX RANGE]
[MIN SHIP SPEED]
[EXCEPT CLASS B]
7. Select [ON] to activate the filter, or select [OFF] to deactivate the filter.
The setting range for [MAX RANGE] and [MIN SHIP SPEED] are listed below.
• [MAX RANGE]: [00NM] to [99NM]
• [MIN SHIP SPEED]: [0.0kn] to [9.9kn]
8. Spin the scrollwheel to adjust the setting as required, then left-click to apply the
setting.
9. Close the menu.
4-16
Filter type
Any AIS targets beyond the range set here will not trigger
the lost target alert.
Any AIS targets slower than this setting will not trigger the
lost target alert.
Select [ON] to prevent class B AIS targets from triggering
the lost target alert.
Definition