Plot Interval; Past Position Display - Furuno FA Manual

4. AIS OPERATION
4.9

Past Position Display

The past position display shows equally time-spaced dots marking past positions
of activated AIS targets. A new dot is added at preset time intervals until the
preset number is reached. If a target changes its speed, the spacing will be
uneven. If it changes course, its plotted course will not be a straight line.
Below are sample past position displays.
(a) Ship turning
4.9.1 Displaying and erasing past position points, choosing past
position plot interval
1. Roll the trackball to choose the PAST POSN box at the right side of the
screen.
2. Push the left button to choose plot interval desired: OFF, 30 s, 1, 2, 3 or 6
min. Choose OFF to erase all past position points and turn off the past
position display.
4-12
(b) Ship running
(c) Ship reduced
straight
Sample past position displays
PAST POSN REL
PAST POSN box
(d) Ship increased
speed
speed
2MIN