Furuno CH-270 - Manual (Page 45)

2. HORIZONTAL MODE
2-25
2.14 Interpreting the Horizontal Display
This section provides information necessary for interpreting the horizontal display.
2.14.1 How the horizontal mode picture is painted
As shown below, the search beam is emitted from the soundome at a certain tilt angle.
The information (target echoes) obtained by this beam is displayed in 6
° (or 12°) sectors
on the screen. With training through the entire area, a large cone shape area is formed,
providing continuous pictures on the display.
Search Beam Screen Display
Tilt:
θ
Search Beam
Tilt: θ
Train: 6 °*
Training Direction
*12 ° When high speed training is
selected.
* 60 transmissions required to complete full circle
(30 in high speed training)
How the horizontal mode picture is painted