Furuno FMD3100, Operator'S Manual

Page: 253 / 395

16. RADAR OVERLAY
16-3
16.3 How to Adjust the Radar Signal Fed From the
Radar Connection Box
Follow the procedure below to set up the radar overlay for the radar connected via the
Radar Connection Box. These adjustments are not necessary for the radar which
feeds the radar signal via LAN.
1. Select the [RCB Common] page from the [Overlay/NAV Tools] box.
2. [Gain] adjusts the strength of the radar signal. Adjust the gain so that the back-
ground noise is just visible on the screen. If the gain level is too low, weak echoes
may be missed. On the other hand, if the gain level is too high, the strong back-
ground noise can hide weak targets.
Note: This setting does not affect the gain set on the radar.
3. [A/C Sea] reduces sea clutter, which is caused by strong reflections from the sea
surface and occurs around own ship in bad weather. Strong sea clutter can pre-
vent identification of targets on the screen. Set the level so that weak sea clutter
appears on the screen. Do not over-adjust the control - approaching targets can
be missed. Set the level at 0 (OFF) if there is no sea clutter on the display to pre-
vent loss of small targets.
4. [A/C Rain] reduces rain clutter, which is caused by rain and snow returns. When
the rain clutter hides targets, use the [A/C Rain] to reduce the rain clutter. The con-
trol operates like the sea clutter control but it is effective not only on near ranges
but longer ranges as well. The higher the setting, the greater the rain clutter re-
duction.
Sea clutter at the
center of the screen. Sea clutter
suppressed.
A/C Rain adjusted;
rain clutter suppressed.
Rain clutter
(starboard direction)