Table of Contents
Advertisement
6 Interpreting Displays
Weak Return From Far-Forward
Strong Return from
Up-sloping Bottom
Principles
The PC/180 system provides a display of acoustic
echos from the underwater area beneath and ahead of
your vessel. The Phased Array Transducer steers an
acoustic beam over a sector which can be adjusted
from 6 to 90 degrees width in the vertical direction
and from 6 to 180 degrees width in the horizontal
direction. As the PC/180 steers the beam to different
positions, it transmits a pulse of energy and then
waits a defined period of time (depending on the
range selected) to receive returning echoes. As the
energy from this acoustic beam strikes underwater
objects or the bottom, a portion of the energy is
reflected as an echo back to the transducer. When
the echo is received at the transducer, it's converted
into a small electrical signal and processed for
display.
Since the PC/180 knows the direction in which it
sent the transmit pulse and the time it took to receive
the return echo, it can determine the location of the
object or bottom that created the return echo. As the
PC/180 sequentially steps through the scan sector,
the computer's display shows a continuously updated
image of the returning echoes in their approximate
positions relative to the vessel.
Interpreting the Vertical
Display
In the vertical mode, PC/180 scans forward from
horizontal down to vertical beneath the vessel. Since
the resulting display shows only the acoustic echoes
that are returned to the transducer, it cannot show
forward bottom conditions that are hidden from its
field of view or are hidden due to obstructions in the
acoustic beam's path through the water.
Forward Imaging Capabilities
The distance ahead of the vessel over which the PC/
40
Advertisement
Table of Contents
