Furuno 1823C manual Reducing Sea Clutter, How the A/C SEA works, Adjusting the A/C SEA

2. RADAR OPERATION

2.5Reducing Sea Clutter

2.5.1How the A/C SEA works

Echoes from waves can be troublesome, covering the central part of the display with random signals known as “sea clutter”. The higher the waves and the higher the antenna above the water, the further the clutter will extend. Sea clutter may affect radar performance because real targets are sometimes hidden by the echoes of small waves. (See the left-hand figure in the figure below.) When sea clutter masks the picture, adjust the A/C SEA to reduce the clutter.

The A/C SEA reduces the amplification of echoes at short ranges (where clutter is the greatest) and progressively increases amplification as the range increases, so amplification will be normal at those ranges where there is no sea clutter.

Sea clutter at	A/C SEA adjusted;
screen center	sea clutter suppressed

Effect of A/C SEA

2.5.2Adjusting the A/C SEA

A/C SEA should be adjusted so that the clutter is broken up into small dots, and small targets become distinguishable.

1.Press the [GAIN] key.

2.Press the A/C SEA soft key to show the A/C SEA setting window.

￿A/C SEA

AUTO ROUGH

°AUTO MODERATE

￿§AUTO CALM

MAN 0

Model 1700 series radar

A/C SEA

0

Model 1800/1900 series radar

A/C SEA setting window

3.When the radar source is the Model 1700 series, use the trackball to select AUTO ROUGH, AUTO MODERATE, AUTO CALM, or MAN (manual) as appropriate. Select an AUTO option according to the sea state.

4.For manual adjustment, rotate the [ENTER] knob to adjust. The range of adjustment is 0-100. Do not overadjust – weak echoes may be missed.

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