Furuno FR-2125V - Manual (Page 88)

5-6
3. Press the [PLOT MENU] key and the [6] key followed by the [ENTER] key.
The reference target mark (see below) appears at the cursor position and the own ship
data label changes from “LOG,” “NAV” or “MAN” to “REF.” Note that it takes 60 scans
or approximately one minute before a new speed is displayed. If tracking has failed for
a reference target, the target is marked with a lost target mark (symbol formed with two
triangles).
R1 (R2, R3)
Changes to in 60 scans
R1 (R2,R3)
Notes on target-based speed
1) When the reference target is lost or goes out of the acquisition range, the reference
target mark blinks and the speed reads “xx.x.” Select a different reference target in this
case.
2) When all targets are deleted, the reference target mark is also deleted and the target-
based speed becomes invalid.
3) The vector of the reference target can be displayed by menu operation (ARPA 1 menu,
[7]).
Canceling target-based speed
Target-based speed may be cancelled through the menu or by the cursor. For menu,
press [PLOT MENU], [6]. For cursor, place the cursor on reference target and press the
[CANCEL] key. The speed is shown by LOG, NAV selected previously.
5.4.4 Deactivating the ARPA
To deactivate the ARPA, press the [RADAR MENU] key followed by the [8] key until the
ARPA is deactivated. Target plotting symbols and the on-screen label ARPA will disap-
pear. The label EPA appears.
5.5 Automatic Acquisition
The ARPA can acquire up to 30 targets (20 automatically and 10 manually or all 30 manu-
ally). If AUTO ACQ is selected after more than 20 targets have been manually acquired,
only the remaining capacity of targets can be automatically acquired. For example, when
20 targets have been acquired manually, then the ARPA is switched to AUTO ACQ. Only
10 targets can be acquired automatically.
A target just acquired automatically is marked with a broken square and a vector appears
within 20 scans of the antenna to indicate the target’s motion trend. Within 60 scans, the
initial tracking stage is finished and the target becomes ready for stable tracking. At this
point, the broken square mark changes to a solid circle. (Targets automatically acquired
are distinguished from those acquired manually. The targets which are acquired manually
are displayed by bold symbols.)