Furuno FSV-24, Operator'S Manual

Page: 33 / 174

2. HORIZONTAL MODE
2-5
For example, when the [RANGE] control, [TILT] control and [AUTO TILT] key are
set to 200 m, 8
°
and width (1) respectively, the tilt angle changes at each
transmission as follows:
8
°
→
9
°
→
10
°
→
9
°
→
8
°
→
7
°
→
6
°
→
7
°
→
8
°
→
…
Tilt angle setting
Figure 2-4 Auto tilt concept
Note: The [AUTO TILT] key is inoperative when the target lock function is active
or is made active. Once the target lock is turned off auto tilt operation is
resumed.
2.4.3 Bottom echo and tilt angle
Refer to the illustration on the next page.
Case 1: Tilt angle 30
°°°°
to 40
°°°°
This tilt angle will display the entire bottom since it is captured by the full width of
the beam.
Case 2: Tilt angle 10
°°°°
to 20
°°°°
This tilt angle will only display half the bottom since it is captured by only the
lower half of the beam.
Case 3: Tilt angle 0
°°°°
to 5
°°°°
This tilt angle may or may not capture the bottom since the returning echo is
weak.
2.4.4 How to discriminate fish echoes from the bottom
The figure at the top of the next page illustrates how two fish schools “a” and “b”
are displayed on the screen using three different tilt angles.
Case 1 (Tilt angle 30
°°°°
to 40
°) °) °) °)
: Fish school is obscured by the bottom.
Case 2 (Tilt angle 10
°°°°
to 20
°)
°) °)
°)
: Fish school is located above the bottom.
Case 3 (Tilt angle 0
°°°°
to 5
°)
°) °)
°)
: Fish school is located close to the bottom.