Principle Of Operation - Interphase Vista Operation Manual

Principle of Operat
The VISTA Forward Scanning Sonar uses a proprietary and
patented phased array acoustic technology first developed for
marine use by Interphase Technologies. Known as "phased
array ultrasound technology", its capabilities have been
proven in the military and medical industries 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.
Most present day fish finders/ depth sounders all work on a
principle developed during W.W. II, called SONAR, where
acoustic pulses are used to detect the presence and range or
distance to an underwater object. During the 1950's, several
devices which used sonar principles were developed and
marketed to fishing and boating enthusiasts to detect the
distance to the bottom (depth) and to indicate the presence of
any intervening submerged objects - such as fish.
An acoustic array is a group of piezoelectric ceramic elements
that are precisely sized and spaced. Each element will send
and receive acoustic pulses, as when used in more
conventional single element depth sounders. However, when
all 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 of
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 of the array, acoustic beams can be directed in an
almost unlimited number of directions. For example, using
an 8 element phased array transducer, the VISTA is capable
of steering the acoustic beam in any of 60 different directions.
Conventional fixed-beam technology would require the use of
60 different elements to duplicate this capability. The
resulting transducer would be much too large and costly to be
of any practical use.
Since the acoustic beam in the phased array is steered
electronically, requiring no moving parts, it can be quickly
and reliably scanned and re-scanned over a large area. When
displayed, the changing information between subsequent
scans takes on an almost animated quality - for example,
vistman1
page 5
ion
5
Award Winning
Technology
For its pioneering work in
developing Phased Array
Scanning Sonar, Interphase
Technologies won the
prestigious IMTEC
INNOVATION AWARD.
The VISTA's Forward
Looking Scanning Sonar is
based on this same award-
winning technology.
Tuesday, July 06, 1999 10:15