Product specifications

Chapter 3: Standard Radar Operations 3-9

Adjusting Gain, Sea

Clutter, Rain Clutter

and Tune

Sea Clutter Control

Radarreturnsfromwavesaroundyourvesselcanclutterthecentreofthe radar

picture (see Figure 3-7, making it difficult to detect real targets. Such sea

clutterusually appears as multiple echoes on the display at short range scales,

andtheechoesarenotrepetitive orconsistentinposition.With highwinds and

extreme conditions, echoes from sea clutter may cause dense background

clutter in the shape of an almost solid disc.

Figure 3-7: Sea Clutter

The SEA controlreduces the gain levelin the areas nearyour vessel,extending

upto3to5nmdependingonthewaveand seaconditions.Thishastheeffectof

reducing the sea returns to intermittent small dots, while small targets are still

visible. Gain levels further from your vessel remain unchanged.

Youcanuse theGainand Seacontrolto helpminimizetheeffectsof sidelobes

(see Identifying False Echo Returns on page 3-5).

Note: 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.

Tuning the Receiver

The TUNE control is used to fine tune the receiver in the scanner for maximum

targetreturnsonthe display. InAutomode,the radartunes itselfautomatically

onall range scales.Werecommend thatyouleave theTUNE controlinAuto

mode.

If you do set the TUNE control to Manual, you will need to adjust it about 10

minutes after you have turned on the radar, since the required setting changes

once the magnetron has warmed up.

You should adjust the control to obtain the maximum signal strength, as

indicated in the 8-step bar above the slider. If you cannot tune the radar

successfully, refer to Section 7.6 for information on the Tune Preset function.

SEA

MANUAL

75%

D3968-1

TUNE