Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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13 3 0 5 8 7 741~0648 US/CA
Portable Underwater Sonar Monitor
The invention relates to sonar equipment and in particular to
a portable underwater sonar monitor.
Background of the Invention
It is known to use a television camera for making underwater
pictures and for underwater monitoring. Such cameras normally
have a small cathode ray tube for showing the scene as
scanned by the camera. Such TV cameras however require a
bright illumination of the scene so that lt is almost
lmpossible to use such cameras in muddy water and in cases
where additional illumination is not permitted. Furthermore -;~
sonar systems are known which scan the scene with sound
pulses and display the echo signals either on a str$p of
paper or on a CRT monitor. The sonar apparatus includes
electroacoustic transducers for generating and transmission
of sound waves and for receiving the echos as reflected by
the target. These acoustic signals are converted by the
transducer into electrical signals and after further signal
processing are displayed or recorded by appropriate
equipment. The electroacoustic transducers in those cases are
positioned either in the hull of the ship or in a particular
transducer gear slidably mounted to the bottom of the ship.
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SUMMARY OF THE INVENTION
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It is the main object of the invention to provide a
portable underwater monitor for divers which monitor can as easily
be handled like a television camera but does not require
additional illumlnation and can also be used in muddy water.
Accordlng to the invention a portable underwater sonar monitoring
apparatus comprislng: a) a fluld tlght housing of essentially
cylindrical or parallelepiped shape; b) at least one handle
rigidly connected to said housing for holding and aiming said
housing with operating elements for manually controlling the
monitor apparatus being provided at said handle or in its
immediate viclnity; c) electroacoustics transmitting/receiving
transducers provided at a first front surface of said housing;
d) an electrooptical display unit in the form of an
electroluminescence screen provlded at the opposite front surface
of said housing for dlsplaying the scene in front of said
apparatus as scanned by said transducers as a pseudo 3-dimensional
profile representation of said scene; and e) said screen including
further indicating surfaces for the diving depth and the
orientation of the monitor as well as for the mode of operation,
the frequency of the sound waves, and the measuring range.
Further details of the invention are described in the dependent
claims. The invention discloses a sonar monitor which scans the
scene by means of sound waves and the image generated by such
scanning i5 presented optlcally on a display provided in the same
housing. Further objects advantages and details of the invention
will become
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apparent when reading the following description of a ~;
¦ preferred embodiment. ; ~
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Brief Description of the Drawings
Figure 1 shows the portable sonar monitor in a
perspective view;
Figure 2 shows a section along the longitudinal axis of
the apparatus;
Figure 3 shows the front surface carrying the display
and
Figure 4 shows the electrooptical display unit
indicating various details of the scene
scanned by the transducers.
The housing essentially is of cylindrical shape and consists
of two portions namely a control and display unit 1 and a
transducer unit 2. On the front surface 3 of transducer unit
2 which is opposite the control and display unit 1 a
transmitting transducer 4, a group of receiving transducers 5
and a further transducer 6 for listening to the echoes are
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provided. Behind the transducers an electronics compartment 7
is provided including the driver stages for the transmitting
transducer and the signal processing electronics for the
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receiving transducers. The receiving transducer consists o~ a
plurality of individual transducer elements such that a
bundled reception characteristic is generated which is
scanned across the field of view of the monitor.
The control and display unit 1 includes an electrolumines- ;~
cence display screen 9 at its front surface 8 which is
opposite of the transducers. Display 9 can be viewed from the
outside through a window 10 which is made of PMMA (Polymethyl-
metacrylat) and provides a fluid tight and pressure tight
cover. The window 10 is provided with an antireflex coating.
In the control and display unit 1 there are also provided
several printed circuit boards 34 for generating the
operating voltage for the display and for signal processing
and slgnal evaluation of the electrlcal signals delivered by
the transducer unit. For indicating the spatial orientation
of the monitor a compa~s 11 and for measuring the diving
depth a pressure sensor 12 are located in the control and
display unit 1. A cable connector 13 covered by a fluid tight
cap may be used for connecting a test apparatus for testing
the monitor. By means of an earphone connector 14 an earphone
15 may be connected to the monitor with the earphone 15 e.g.
being located in the helmet of the diver. By means of the
earphone 15 and the listening transducer 6 any sources of
nolse can be monitored in the space around the apparatus.
Both parts 1 and 2 of the housing each form a pressure tight
and fluid tight unit and can be used separately if required -
and in this case will be connected to each other by means of
a cable.
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A bow shaped handle 16 is rigidly connected to the housing 17
of the control and display unit 1. This handle 16 serves for
holding and aiming the monitor. Operating elements 18 e.g.
pressure tight switches are associated with the handle on
both sides of the unit 1. A power supply unit 19 co~prising
several batteries or rechargeable batteries can be removed
and replaced without opening the housing 17. The outer shape
of the power supply unit fits into the outer shape of the
entire housing 17, 20 of both units 1 and 2. Housing 20 of
the transducer unit 2 is shaped by means of portion 21 such
that it together with battery compartment 19 forms a stream-
lined shape of the entire housing 17, 20. In order to balance
the monitor in the water bouyancy means might be provided
within the housing or its ~acket 21. Such means also could be
addltionally fastened to the housing. The control elements 18
can elther be provlded at the handle 16 or at the housing 17
in the immediate vacinity of the handle 16. The electro-
lumine-~cence display 9 ls inclined by about 60 degrees with
respect to the longltudlnal axls 22 of the houslng so that
the diver can readily look onto the dlsplay of the monitor
whlch floats ln front of hlm. Both houslngs 17 and 20 may
comprise of fiberenforced plastlc material into which metal
lnserts are lntegrated for fastenlng the indivldual
components and the control elements.
Dlvldlng the houslng lnto a transducer unit 2 and a control
and dlsplay unit 1 makes it possible to fix the transducer
unlt 2 to a separate carrier, e.g. a bouy or a frame or
linkage and to provide the control and display unit 1 on
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board of a ship. In this case both units are connected to
each other by means of a multiwire cable. For this purpose
both units 1 and 2 are electrically connected to each other
by means of a connector unit 23 so that for using both units
separately the cable has to be inserted between the two parts
of the connector unit.
Figure 4 shows a view on display 10. In a profiled type
display it shows the viewing area ahead of the monitor and
includes additional markings 24 for the angular displacement
and further has distance marks 25. Guided by those marks the
viewing area is shown like a profile so that e.g. a wreck 26
is shown in its spatial representation. A compass dial 27
together with a pointer 28 can be read at the display 10
which also has a battery exhaust indicator 29. In a
particular field 30 the diving depth is indicated. A control
fleld 32 positioned below the profile representation 31 of
the viewing area indicates several characteristic data or
parameters of the presently selected mode of operation, e.g.
the distance range, the amplification factor and the lower ~ ~
limit of the received signals from which on the signals are ~ -
indicated. Signals having a lower amplitude, as e.g. signals
from fishes or plankton, are suppressed to avoid interference
with the display representation. Finally an indicator shows
whether or not the listening channel and listening transducer
is operating. Furthermore the frequency of the scanning
signals is indicated. In the case as shown this frequency is
25 kHz. The depth is 12m, the listening channel is switched-
off (AUS). The monitor works in mode 1. These modes may
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distinguish between scanning and tracking mode, narrow beam
and wide beam scanning etc. The distance range is lOOm. The
amplifying factor is 6 and the minimum level is 3. In the -
embodiment shown in figure 4 the angular marks 24 are
provided in relation to north-south direction. They also
could be given in relation to the longitudinal axis 22 of the
monltor apparatus. Reference to the north-south direction in
accordance with the compass dial 27 is particular useful in
the case when transducer unit 2 and control and display unit
1 are used separately. A electroluminescence display i5 of
particular advantage in view of its flat shape and the low
supply voltage required for thls type of display. A carrying ~
handle 23 is provided at the housing 17 of the control and ; ;
di~play unit 1 just above the compartment for the printed
clrcuit boards 34.
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