Abstract: The invention is a method and apparatus for non-contact measurement of the length and height or diameter of geometrically regular objects. The objects enter a first measurement station where horizontally opposed echo ranging transducers make sequential differential measurements to determine the length and transverse position of the object. Position information is sent to a microprocessor. The object is then advanced under a transverse array of downwardly oriented echo ranging transducers. The microprocessor preferrably selects the single transducer located most closely to the mid-length position of the object to make a height or diameter measurement. In the case of cylindrical objects, the object should be oriented with its axis parallel to a line projected between the opposed length measuring transducers. As the object is moved by the diameter sensing transducer, the microprocessor selects the measurement indicating the shortest distance between the object and the transducer.

Abstract: A sonar beam steering arrangement in which a circular array of electroacoustic transducers are sampled in sequence, the samples being digitized and stored serially in a shift register. The register is several cycles long so that samples from all of the `illuminated` transducers can be stored simultaneously. The various stages have resistance tappings of different values such that a linear broadside array is simulated for a particular transducer at a particular stage in the shift register cycle. As the samples progress through the register each transducer in turn acquires this simulated broadside array and thus provides a narrow beam 360.degree. scan. Interpolation between adjacent transducer `dead-ahead` direction is obtained by (e.g.) triplicating the shift register and adjusting the weightings slightly from each register to the next.

Abstract: A thin-line heading sensor is disclosed having an outside diameter of less than an inch which is accurate to within 1.degree. of arc. The invention includes a magnetic wheel having a reflective multifaceted perimeter. The facets are optically coded for identification. When the wheel is illuminated by a collimated beam of light, a beam is reflected onto an array of photodetectors. The photodetectors are coupled with an electronic circuit which decodes the position and pattern of illumination to determine the position of the magnetic wheel.

Abstract: An acoustic distance measuring system for detecting a small change in position of a remote object and changing the state of a relay. An acoustic transmitter and receiver are connected by an amplifier circuit which is induced into oscillation when a portion of the transmitted acoustic signal is reflected by a remote surface back to the receiver, forming an external feedback path, said oscillations occurring only in alternate half wavelengths of feedback path length, in which the reflected waves are generally in phase with the transmitted waves. A detector circuit responsive to the amplifier oscillations provides an output which is used to change the state of a relay.

Abstract: Acoustic positioning device for a vessel comprising N transponders (B.sub.1 . . . B.sub.i . . . B.sub.N).A fixed acoustic transmitting means (E) periodically transmits acoustic pulses at frequency f. The responses of the transponders (B.sub.1 . . . B.sub.i . . . B.sub.N) are received by the acoustic array (A.sub.1, A.sub.2) of the vessels. The time origins are transmitted by a radio antenna to the surface vessel. In the case of submarines, two stable clocks are used, one of which is on board the submarine. Processing circuits make it possible to know the position of submarines.Application to the positioning of vessels in an oil production field or for oceanographic research.

Abstract: A multielement acoustic transducer comprising a metal plating which is formed by plating the convex surface of a low-melting metal having a plurality of convex semispherical holes and then fusing and removing the low-melting metal, the metal plating being used as a base electrode, a piezoelectric material which is formed on the base electrode, and a top electrode which is formed on the piezoelectric material, the piezoelectric material functioning as concave transducer elements.

Abstract: The method and arrangement contemplates transmitting externally triggered trigger pulses by means of a magnetostrictive line or conductor and such produces echo pulses. Displacement path and time oscillator pulses are counted by two counter groups, and there is computed from the counter state the velocity-corrected position of a measuring head. Consequently, with a higher measuring rate there can be appreciably increased the accuracy of the evaluation of the pulses delivered by the ultrasonic measuring system, there can be obtained further measuring data (velocity and acceleration) by means of the moving measuring head, and there is possible an absolute measurement. Additionally, the resolution of the measured displacement path or distance can be randomly selected by means of the frequency of the displacement path or distance oscillator.

Abstract: An array with high resolving power and low secondary lobe levels, comprising a receiving array formed of transducers along its length L.sub.R, two of these transducers, separated by a distance L.sub.E, also forming the transmitters. The change from transmission to reception and back is effectuated by switches. Signals received by transducers are weighted by resistors before being delivered to beam forming circuits, containing multi-terminal phase shifters and a wiring matrix and adders. The weighting function and ratio L.sub.E /L.sub.R are chosen to ensure that the overall transmission-reception system diagram has high resolving power and low secondary lobe levels.

Abstract: Problems of resolution and focussing arise in the near field in systems employing radiation, including ultrasonic systems. These problems can be alleviated by suppressing the plane waves in the combination of plane waves and edge waves usually employed. Several ultrasonic transducers with this property are described and in one a piezoelectric disc with surface electrodes is non-linearly polarized to transmit edge waves without plane waves.

Abstract: An apparatus for locating, classifying and identifying underwater marine animals by means of the sounds they make includes an elongated submersible array adapted to be towed in various directions. The array is made up of subarrays of multiple hydrophones which are arranged along the length of each subarray in groups. By changing the combinations of groups, the frequency response and the directional sensitivity of the array can be varied. The outputs of the groups can be selectively analyzed both visually and audibly for characteristic fish sounds. The received sounds are classified and used for the identification of newly found fish.

Abstract: In a panoramic sonar for underwater detection, a channel formation device supplies channels sequentially over 360.degree. from a circular base of N receiving transducers, one channel being formed from M transducers. The signals received by the N transducers are multiplexed and applied to two subassemblies. One subassembly is composed of shift registers corresponding to N and N-1 cells (C.sub.N, C.sub.N-1) and the other subassembly is composed of shift registers corresponding to N and N+1 cells (C.sub.N, C.sub.N+1). Taps on the subassemblies make it possible to obtain the delayed signals corresponding to the M receiving transducers. The signals are summated and applied sequentially to the channels.

Abstract: A method of transmitting half-sinewave ultrasonic monopulses utilizes a flip-flop (22) to reverse the states of a bridge circuit (Q.sub.1 -Q.sub.4) with each output pulse from a timing pulse generator (20). This reverses the polarity of a dc voltage which stresses a piezoelectric transducer (24) to substantially its limit. Each pulse from the timing generator thus causes one mechanical transition of the transducer and clamps it in its reversed stress condition, thereby producing a half-sinewave ultrasonic output for each timing pulse.

Abstract: A system measures the (x, y) coordinates of a target, for example, a pointed finger on a flat surface such as a rectangular plate. A pair of ultrasonic transducers are placed on the plate so that one transducer is located at each of the two left corners of the plate or at each of the two top corners of the plate. The transducers transmit short ultrasonic pulses which are reflected as echos off the target and then received by the transducers. The time elapsed between the transmitting of each pulse and receiving its echo is converted into distances between the transducers and the target, which distances are then converted into the target's (x, y) coordinates.The system is designed to clamp onto a number of flat surfaces, thereby allowing the system to be used with printed representations of keyboards, graphs, CRT monitors and standard television screens. The system is interfaced with any of a variety of computers and provides a signal representative of the location of the target to the computer.

Abstract: The measuring apparatus is intended for the automatic measurement of speed, travelled distance and directional changes, wherein two measuring units (3, 3a) are disposed in spaced relationship on the underside (4) of a vehicle (5). Upon a comparison of the left-hand and the right-hand signal a measurement of the directional change is effected, wherein each measuring unit (3, 3a) respectively comprises a forwardly and a backwardly measuring and transmitting measuring section (I and II, respectively); thereby errors of measurement caused by pitching motions of the vehicle may be minimized to less than 0.1%.

Abstract: Echo-sounding apparatus with circuitry for achieving enhanced recording on electrically sensitive paper is disclosed in which the gain of a variable gain amplifier is reduced exponentially depending on the input signal amplitude as soon as this amplitude exceeds a predetermined level. The signal generated by the variable gain amplifier is supplied to low pass and high pass filters which are connected to two inputs of a differential amplifier which controls the recording element.

Abstract: A circuit for measuring and indicating the separation distance between a vehicle and adjacent obstacles, consisting of a pulse controlled ultrasonic generator, an ultrasonic transmit-receive transducer connected to the generator for transmitting direct ultrasonic pulse signals to distant obstacles, and receiving these signals that are reflected from the obstacles, an amplifier and detector circuit connected to the transducer output for amplifying the received pulse signals, a first comparator which is connected to the amplifier and and detector stage, and a start-stop counter coupled to the output of the first comparator for measuring the difference in time between the end of the transmitted ultrasonic signal, and the reception of the reflected signal from the obstacle. There is also provided a noise suppression circuit coupled to the output of said first comparator and a second comparator coupled to both the output of the noise suppression circuit and the output of said start-stop counter.

Abstract: Method and apparatus for determining the length of a tubular member such as a pipe are disclosed. A burst of acoustical pulses are emitted from a sending unit and are received by a reference acoustical transducer and by a slave acoustic transducer. The slave transducer emits a return pulse which is used to compute the duration of the sound propagation interval between the ends of the pipe. A phase angle compensation factor is computed by measuring the phase shift of the signal received by the reference transducer with respect to the signal emitted by the master transducer.

Abstract: Method and apparatus for web break detection employing a sonic signal generator to generate regularly repetitive sonic signals of selected frequency, duration and time spacing between signals and disposed to direct the sonic signals toward a moving web of selected material so the signals are reflected from the web, a receiver device to receive the reflected signals, a time signal generating device to generate signal pulses during the time period between the generation of a sonic signal and receipt of the reflected signal a counter device to count the time generated between the transmission of the sonic signal and the reflected signal so that the number of time signals generated is indicative of the presence of the web as well as the distance of the web from the signal generator and receiver and a logic system to actuate a cutter mechanism to cut the web if it should fall outside a preselected "window" in which the web is positioned.

Abstract: A sonar system comprises a vehicle (1) capable of moving over the bottom of an extent of water, with an emitter of acoustic pulses and a receiver of acoustic energy mounted on said vehicle. Signal processing and display circuitry (e.g. on board a surface vessel 2) are connected to receive signals representative of the acoustic waves emitted by the emitter, of the acoustic waves received by the receiver, and of parameters describing the motion of the vehicle. The signal processing and display circuitry generates an image of objects hidden in the water bottom on the basis of the signals. The emitter of acoustic pulses is provided with at least one parametric transducer having a spot radiation pattern capable of forming a plurality of channels that bathe spots of the water bottom in sound waves, and an electronic pointing system for scanning the channels.

Abstract: A photographic camera having a plurality of interchangeable, adjustable focus lenses and having a focus control system capable of focusing each such lens over a range of subject distances in response to a rangefinder derived signal is provided with a sonic ranging system that includes an ultrasonic, capacitance-type transducer having a multiple segment backplate whose sonic beam angle is automatically correlated to the field-of-view angle of the image forming lens by selecting a particular combination of backplate segments when or as a particular interchangeable lens is attached to the camera body.