Furuno 1954C-BB, GD-1920C-BB Advancement synchronized with ship’s speed, Picture advance window

4. VIDEO SOUNDER OPERATION

PICTURE ADVANCE

▲

2/1

1/1

1/2

1/4

1/8

1/16

STOP

▼

Picture advance window

4.Use the Trackball to select speed desired. The fractions in the window denote the number of scan lines produced per transmission. For example, 1/8 means one scan line is produced every eight transmissions. STOP freezes the display and it is convenient for observing an echo.

5.Press the E: RETURN soft key followed by the MENU key to close the menu.

Note: When using the plotter/sounder combination display, advancement of the sounder picture may be temporarily interrupted while the plotter display is being shifted or its display range is being changed.

4.9.2Advancement synchronized with ship’s speed

With speed data provided by a speed-measuring device, picture advance speed may be set according to ship’s speed, the ship’s speed dependent mode. As shown in the figure below the horizontal scale of the display is not influenced by the change of ship’s speed, thus the speed-dependent picture advance permits judgment of fish school size and abundance at any speed. The choice “SPD SENSING PRR” means the ship’s speed dependent mode, where the PRR changes automatically with ship’s speed.

Fish school shrinks as speed is increased; expanded

as speed is decreased.

Same size fish schools

FULL￿ HALF￿

Speed SPEED SPEED

Actual Movement

Normal Mode

Fish schools are shown same size regardless of ship's speed.

Speed-Dependent Picture Advance Mode

How the speed-dependent picture advance mode works

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