Chapter 7: Using the Radar (Analog)
161
Manually adjusting the gain modes
The gain, sea, FTC and rain controls can all be adjusted manually if necessary:
Note:
The new values remain set even when you switch off the display and are applied
to both the active window and any other radar windows. Analog
Sea
Radar echoes from waves around your boat can clutter the centre of the radar picture,
making it difficult to detect real targets (see
page 152
).
Adjusting the sea mode will reduce this clutter for up to 5 nautical miles (depending on
wave and sea conditions) from your boat. This has the effect of reducing the sea echoes
to intermittent small dots whilst small targets remain visible and persistent. Gain
levels further from your boat remain unchanged. There are three sea gain modes:
•
HBR
(Automatic Harbor mode) - this takes account of the effects of land clutter so
that small target are not lost. It should be used when you are in harbor or in close
proximity to land.
•
OSH
(Automatic Offshore mode) - the system continually calculates the required
level of sea clutter control.
•
MAN
(Manual mode) - this enables you to select the sea clutter level and then
adjust the settings to ensure that all close small targets are visible. On short range
scales, do not set the SEA control so high that all clutter is removed, since this could
stop you seeing echoes from close targets. The acuteness of the sea clutter curve is
set up in the Radar Setup menu (see
page 180
). Manual sea clutter mode should be
used in conjunction with the GAIN function (described below).
• Coastal
(Automatic Coastal mode) - The system automatically selects mean levels
for coastal radar operation.
GAIN
D8406_2
Press to highlight
Toggle to manual (MAN)
RAIN
FTC
ON OFF
AUTO
RAIN
Adjust
level as
required
MAN
50
GAIN
AUTO MAN
SEA
AUTO
SEA
MAN
GAIN
AUTO MAN
FTC
ON OFF
81244_4.book Page 161 Thursday, January 31, 2008 1:53 PM
