Furuno FSV-30, Operator'S Manual

Page: 118 / 190

5. HISTORY MODE
5-2
5.2 Sample History Display
The history display shows echo data for the echoes within the history marker,
which is a 120 ° arc centered on the own ship position on the horizontal display.
The history marker scrolls downward on the history display – the latest echoes at
the top and the oldest at the bottom. Echoes are averaged for three
transmissions for easy viewing. This mode is useful for watching echo condition
over a period of time.
Use the trackball to select location for the history marker. When the tilt angle is
changed, the slant range is automatically changed to keep the history marker at
a constant depth; however, like an echo sounder, the picture inscribed before the
tilt angle was changed is not refreshed.
N
W
S
E
0
150
25
E
NUMERIC/GRAPHIC
DATA DISPLAY
History
marker
Horizontal Display
History Display
560m
51m
→
↓
History display
A
B
C
Depth
D
A
C
D
B
History marker and echo location
B
A
History mode concept