Furuno 1833, 1943, 1933 manual Echo Averaging, Effect of echo averaging

2. RADAR OPERATION

2.20Echo Averaging

The echo averaging feature effectively suppresses sea clutter. Echoes received from stable targets such as ships appear on the screen at almost the same position during every rotation of the antenna. On the other hand, unstable echoes such as sea clutter appear at random positions.

To distinguish real target echoes from sea clutter, echo average performs scan-to-scan correlation. Correlation is made by storing and averaging echo signals over successive picture frames. If an echo is solid and stable, it is presented in its normal intensity. Sea clutter is averaged over successive scans resulting in the reduced brilliance, making it easier to discriminate real targets from sea clutter.

To properly use the echo average function, it is recommended to first suppress sea clutter with the A/C SEA control and then do the following:

1.If not displayed, press the [HIDE/SHOW] key to display the radar soft keys.

2.Press the SIGNAL PROC. soft key.

3.Press the E. AVG soft key to select desired echo averaging.

OFF: No averaging

LOW: Helps distinguish targets from sea clutter and suppresses brilliance of unstable echoes.

MED: Distinguishes small stationary targets such as navigation buoys.

HIGH: Stably displays distant targets.

4. Press the RETURN soft key to finish.

The display shows EAV L, EAV M or EAV H when echo averaging is on.

(a) Echo average OFF (b) Echo average ON

Effect of echo averaging

2-28