Furuno FR-8125 ユーザーズマニュアル

ページ / 120
3-1
3.
ARPA OPERATION
The Automatic Radar Plotter ARP-11 (option) manually or automatically acquires and 
tracks ten targets. When a target is acquired automatically or manually, a target is au-
tomatically tracked within 0.1 to 16 nm.
3.1
Precautions for Use
3.2
Controls for Use with ARPA
ENTER: Acquire the cursor-selected target. Display data for tracked target (in the data 
box at the bottom of the screen).
CANCEL/HL OFF: Remove data of cursor-selected tracked target from the data box. 
Stop tracking the cursor-selected target (when its data is not displayed in the data 
box).
MENU: Access the [Target] and [ARPA] menus for ARPA operations.
CursorPad: Select a target to acquire (or cancel the tracking). Select a target to show 
(or remove) target data.
Do not depend on one navigation device
for the navigation of the ship. The
navigator must check all aids available
to confirm position. Electronic aids are
not a replacement for basic navigation
principles and common sense.
· The ARPA automatically tracks an
   automatically or manually acquired radar
   target and calculates its course and
   speed, indicating them by a vector. Since
   the data from the auto plotter depend on
   the selected radar targets, the radar must
   be optimally tuned for use with the auto
   plotter, to ensure required targets will not
   be lost or unnecessary targets like sea
   returns and noise will not be acquired
   and tracked.
· A target is not always a landmass, reef,
  ship, but can be returns from the sea
  surface and clutter. As the level of clutter
  changes with the environment, the
  operator must correctly adjust the A/C
  SEA
A/C RAIN and GAIN controls so
  that the target echoes do not disappear
  from the radar screen.
The tracking accuracy is affected by the
following:
· The tracking accuracy is affected by
   course change. One to two minutes is
   required to restore vectors to full
   accuracy after a sudden course change.
   (The actual amount depends on
   gyrocompass specifications.)
· The amount of tracking delay is inversely
   proportional to the relative speed of the
   target. Delay is on the order of 15-30
   seconds for high relative speed; 30-60
   seconds for low relative speed.
The display accuracy is affected by the
following:
· Echo intensity
· Pulse width of radar transmission
· Radar bearing error
· Gyrocompass error
· Course change (your ship or target)
CAUTION
CAUTION
CAUTION
CAUTION