Raymarine Marine GPS System - Manual (Page 105)

RayTech Navigator User’s Guide
5-14
4. If you select Manual mode, the arrow control buttons
appear. Use the up/down arrows to increase/decrease the
Manual Gain. Important: Because the changes to the
settings are made immediately, you cannot revert to the
previous setting by clicking
CLEAR .
5. When you have set the controls to the levels you require,
press ENTER , CLEAR , or BACK to return to the default
level of soft keys.
Sea Clutter Control
Radar returns from waves around your vessel can clutter the center of
the radar picture, making it difficult to detect real targets. Sea clutter
(Figure 5-5) usually appears as multiple echoes on the display at short
range scales, and the echoes are not repetitive or consistent in position.
With high winds and extreme conditions, echoes from sea clutter may
cause dense background clutter in the shape of an almost solid disc.
Figure 5-5. Radar Sea Clutter Display
The Sea Clutter control reduces the gain level in the areas near your
vessel, extending up to 3 to 5nm depending on the wave and sea
conditions. This has the effect of reducing the sea returns to
intermittent small dots, while small targets are still visible. Gain
levels further from your vessel remain unchanged. You can use the
Gain and Sea Clutter control to help minimize the effects of side lobes.