Suppressing Rain Clutter, Measuring the Range

Manual A/C SEA adjustment

While observing the screen and the A/C SEA tuning bar, press ◄ or ► to set the A/C SEA. The setting range is 0-100.

4. Press the [MENU/ESC] key to finish.

1.9 Suppressing Rain Clutter

The vertical beamwidth of the antenna is designed to see surface targets even when the ship is rolling. However, by this design the antenna will also pick up rain clutter (rain, snow, or hail) in the same manner as normal targets. The illustration below shows the appearance of rain clutter on the display.

The A/C RAIN control adjusts the receiver sensitivity as the A/C SEA control does but rather in a longer time period (longer range). The higher the setting the greater the anti-clutter effect.

Rain clutter at screen center

1.Press the [GAIN] key consecutively until the display shown below appears.

A/C RAIN

[GAIN] : GAIN MENU

[MENU/ESC] : Exit.

A/C RAIN adjustment window

2.While observing the screen and the A/C RAIN tuning bar, press ◄ or ► to adjust the A/C RAIN. The setting range is 0-100.

3.Press the [MENU/ESC] key to finish.

1. OPERATION

1.10 Measuring the Range

The bearing to a target can be measured by the range rings, by the cursor and by the VRM (Variable Range Marker).

Measuring range by the cursor

Operate the cursor pad to place the cursor on the inside edge of the target. Read the range to the cursor at the bottom right corner of the display.

Measuring range by the range rings

Count the number of rings between the center of the display and the target. Check the range ring interval and judge the distance of the echo from the inner edge of the nearest ring.

Note: The range rings can be turned on or off with RINGS on page 1 of the System menu.

Measuring range by the VRM

1.Press the [MARK] key to show the Mark menu.

MARK MENU

[GAIN] : EBL

[ALARM] : VRM

[MARK] : TLL OUTPUT

Mark menu

2.Press the [ALARM] key to display the VRM, which is a dashed ring to distinguish it from the range rings.

3.Operate the cursor pad to place the VRM on the inside edge of the target.

4.Check the VRM readout at the bottom left corner on the screen to find the range to the target.

To anchor the VRM on the screen, press the [MENU/ESC] key. To erase the VRM, press the [ALARM] key twice with the MARK MENU displayed.