Interphase Proble Operation Manual page 48

echoes from both fish targets at the same time and the
display will only show a single target. This is a serious
limitation to the conventional technology.
To get around this limitation, several manufacturers have
resorted to adding more piezoceramic elements to the
transducer, each pointed in a different direction. By
selectively using each piezoceramic element the
transducer has the ability to point or look in as many
different directions as there are piezoceramic elements.
After approximately four elements, however, the
transducer housing starts to become physically large and
cumbersome. To date, manufacturers have put as many
as five separate elements into the transducer to enable
users a view in up to five different underwater directions.
In the future, Interphase believes that this multiple fixed-
beam approach has serious limitations, especially for use
in more adva ced products where maximum underwater
coverage and resolution are important.
Development of New Technology
To get around these limitations and provide a sonar
system that can achieve both outstanding coverage and
good resolution, Interphase pioneered the use of
Ultrasonic Phased Array Technology. In 1991 we
received the prestigious IMTEC Innovation Award in
recognition of the importance of this new technology to
the marine industry. Although new to the sportsfishing
and recreational marine industry, "phased array
ultrasound technology" has proven its capabilities in the
medical industry for many years. The amazing video
images provided by medical ultrasound equipment are
familiar to most people and clearly demonstrate the
technology's ability to show highly defined images in a
real-time or live-action mode. Interphase has taken this
same technology and modified it for use in the marine
market.
An acoustic phased array is a group of piezoceramic
elements that are precisely sized and spaced. Each
element will send and receive acoustic pulses as when
used in the conventional single element technology.
However, when all the elements in the array are sending
or receiving acoustic energy at the same time, the entire
array behaves like a single larger element with one
important difference: the ability for the array to
concentrate its acoustic energy in different directions
depending on the different "phasing" of the signals
applied or received by each element. Depending on the
signal phasing to the array, acoustic beams can be
directed in an almost unlimited number of directions. For
Three Fixed-Beam System, Looking Down and
to Each Side of Boat
12º Acoustic Beam Can
Be Steered In Any
Direction Over a 90
Degree Arc.
8 Element
Ceramic
Phased
Array
48
Bottom