User Manual

19
3.3.3 Shifting away from obstacles
1. Shifting from keel line
By shifting the scanner position from the keel line to the starboard side of the ship, it is
possible to move shadow zones to the port side which makes it possible to keep vision clear in
the bow direction. The distance to be shifted can be obtained by calculation depending on the
distance from the scanner to obstacles using the following equation:
Ls=0.4R+D/2 [m] (when R<15m)
Ls=0.025R+D/2 [m] (when R>=15m)
where Ls = distance to be shifted from keel line
D = diameter of obstacle on keel line
R = distance from scanner to obstacle
Fig.3-1 Shifting from keel line
2. Obtaining sufficient dip angle
Raise the scanner position so that there is a sufficient dip angle
θ
available between the
line of sight from the scanner to the obstacle and the horizontal line. By raising the dip angle
above 5
°
, it is possible to prevent mid- and long-distance shadow zones. The radar cannot
detect objects below the line of sight.
Fig.3-2 Obtaining sufficient dip angle
Ls
R
D
Scanner Unit
Obstacle
Keel line
Horizontal line
Line of sight
θ