CA42/50/52 Echosounder operation
Chapter 7
96
The center of the sound beam is the most intense, then as you move out
towards the sides of the sound beam there is a point where the intensity
of the sound is half what it was in the center. The distance moved is the
“beamwidth”. See Figure 3.
7.12 Effects of the vessel’s speed
The display of fish on the CAXX depends directly on the vessel’s
speed, as well as on the depth of the fish. When the vessel is at rest, the
echo traces will appear stretched and flattened. As the vessel’s speed
becomes greater, the echo traces will become shorter and more arched.
The reason for this change in appearance is that as the vessel speed
increases fewer number of sound “pings” strike each fish. A low vessel
speed will provide the most accurate information of where fish are
located.
