Furuno FAR-2107(-BB) - Manual (Page 51)

1. RADAR OPERATION
1-29
RAIN
Place arrow inside window
to adjust A/C RAIN.
Level bar
(Shows A/C RAIN level.)
30
1.18 Reducing Rain Clutter
Use the AUTO RAIN and A/C RAIN to reduced rain clutter. AUTO RAIN reduces
rain clutter in the picture and A/C RAIN reduces clutter picked up by the antenna.
Note 1: When both sea clutter and rain clutter are reduced the sensitivity is
decreased more than when only one is adjusted. For that reason adjust
them carefully.
Note 2: The echo average (see 1.27) is useful for reducing reflections from the
sea surface. However, high-speed targets are harder to detect than
stationary ones when the echo average is active.
1.18.1 Automatic reduction of rain clutter
Left-click the AUTO RAIN indication at the left side of the screen to select AUTO
RAIN setting desired. The higher the number, the greater the degree of rain
clutter reduction. OFF turns off the AUTO RAIN feature.
Note: AUTO RAIN can also be controlled from the PICTURE box.
1.18.2 Manual reduction of rain clutter
The vertical beam width of
the antenna is designed to
see surface targets even
when the ship is rolling.
However, by this design
the unit will also detect rain
clutter (rain, snow, or hail)
in the same manner as
normal targets.
The A/C RAIN control adjusts the receiver sensitivity as the A/C SEA control
does but rather in a longer time period (longer range). The higher the setting the
greater the anti-clutter effect. When echoes from precipitation mask solid targets,
adjust the A/C RAIN control to split up these unwanted echoes into a speckled
pattern, making recognition of solid targets easier. Be careful remove all rain
clutter, because you can erase weak echoes. Further, the possibility of losing
weak echoes is greater when you use both A/C RAIN and A/C SEA to reduce
clutter.
Keyboard
1. Use the trackball to put the cursor
in the A/C RAIN level indicator at
the top right side of the display.
2. While observing the A/C RAIN level
indicator, roll the scrollwheel
downward to increase the A/C RAIN
or upward to decrease it. 100 levels
(0-100) are available.
Unwanted echoes are
displayed A/C RAIN control adjusted.