How To Reduce Low Level Noise; How To Erase Weak Echoes - Furuno GP-3700F Operator's Manual

11. ECHO SOUNDER
11.8

How to Reduce Low Level Noise

Low intensity "spots" of noise appear over most of the screen like in the illustration
shown below. These spots are caused by sediment in the water or noise. You can re-
duce this type of noise by adjusting CLUTTER on the menu.
Note: This function is not available in the automatic mode.
1. Press the MENU key to open the main menu.
2. Select [9. ECHO SOUNDER SETTING].
3. Select [3. CLUTTER].
4. Set the clutter rejection level. The larger the setting value, the greater the degree
of suppression. Set the level to "0%" when no clutter exists, to prevent erasure of
weak echoes.
5. Press the DISP key to close the menu.
11.9

How to Erase Weak Echoes

Sediment in the water and reflections from plankton appear on the display in low-in-
tensity colors. These weak echoes can be erased by using the [ERASING WEAK
ECHOES] function. This function erases weaker echoes sequentially to show only
strong echoes and clear up the picture.
1. Press the MENU key to open the main menu.
11-14
Weak echoes