Past Position Display Motion; Stabilization In True Motion; Lost Target; Lost Target Filter - Furuno FAR-2807 Operator's Manual

4. AIS OPERATION
4. Select 5 AIS PAST POSN POINTS.
5. Select 5 or 10 as appropriate.
6. Push the right button three times to close the menu.
4.9.3

Past position display motion

The past position display may be shown in true or relative motion. Open the
TRAIL menu and set TRAIL MODE to TRUE or RELATIVE as appropriate.
4.9.4

Stabilization in true motion

The true motion past position display may be ground stabilized or sea stabilized.
The PAST POSN box shows current stabilization as TRUE-G or TRUE-S. To
change the stabilization mode, open the SPEED menu and set SHIP SPEED to
BT (ground stabilization) or WT (sea stabilization).
4.10

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 "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 push the left button.
Note 1: If a TT lost target mark is displayed when the [ALARM ACK] key is
pressed (or the ALERT box is clicked) to acknowledge an AIS lost target,
the TT lost target also is erased.
Note 2: The AIS data transmission interval depends on target's speed. For
example, the data is transmitted every 10 seconds on ship speed of 0 to
14 knots and every two seconds on the ship speed of more than 23
knots. For details see the owner's manual of the AIS.
4.10.1

Lost target filter

If there are a lot of AIS targets in your area, the lost target alert may 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. Left-click the MENU box to open the menu.
2. Select 4 [TT AIS] to open the TT
3. Select 8 [AIS LOST FILTER].
4-16
Lost target
.
AIS menu.