How To Set Own Ship's Speed; Automatic Speed Input (Log Or Epfs Navigator) - Furuno FAR-2218-BB Operator's Manual

1. OPERATIONAL OVERVIEW
1.12

How to Set Own Ship's Speed

The TT and azimuth stabilized presentation modes require own ship speed input and
compass signal. The speed can be entered from a log (STW, SOG) or EPFS (SOG)
or manually on the menu.
Note: Where the own ship speed exceeds 99.9kn, the displayed speed is "99.9kn".
1.12.1

Automatic speed input (log or EPFS navigator)

1. Place the cursor on the [SPD
heading box at the top-right of the screen, then
right-click. The [SPD] context menu appears.
2. Select [2 SHIP SPEED], then press the ENTER
MARK key.
3. Select the appropriate source for automatic
speed input, then press the ENTER MARK key.
Selection
[LOG (BT)]*
[LOG (WT)]
[EPFS]
[MANUAL]
[REF]
[ECDIS]*
1
* : Set and drift may be required to display [LOG (BT)] correctly in deep waters.
To change set and drift, see section 3.14.
2
* : Where [ECDIS] is selected as the speed source, [4 OWN SHIP POSN] in the
[OWN SHIP INFO] menu is automatically set to [ECDIS] also. See section 1.13.
4. If you selected [MANUAL] as the speed data source, see section 1.12.2 to set the
speed.
5. Close the menu.
Notes on speed input
It should be noted that in determining a target's aspect by radar, the calculation of its
true track is dependent on the choice and accuracy of the own ship's course and
speed input. A ground-stabilized target plot may accurately calculate the ground track
of the target, but the target's heading may be significantly different from its track when
experiencing set, drift or leeway. Similarly, a sea stabilized target plot may be inaccu-
rate when own ship and the target, are experiencing different rates of set, drift or lee-
way.
• IMO Resolution A.823(19) for TT recommends that a speed log to be interfaced with
a TT should be capable of providing through-the-water speed (forward speed).
1-18
Explanation
Log, speed over ground (SOG)
1
Log, Speed Thru Water (STW)
Speed input by GPS navigator
Manually input speed
Echo-referenced speed input
Speed input by ECDIS
2
] indication in the
Ground stabilization
Sea stabilization
Ground stabilization
Sea stabilization
Ground stabilization
Ground stabilization or Sea
Stabilization (Dependent on
ECDIS settings).
Stabilization Mode