Abstract: A wide band, substantially constant beamwidth, frequency independent, scable acoustic array uses a mosaic pattern acoustic lens arrangement of fully directive acoustic lens antennas as the primary array antenna elements. The lenses at the center of the array pass signals at all frequencies, the lenses near but not at the center pass all signals except those at the highest frequencies and the lenses on the outer periphery pass only those signals at the lowest frequencies. When used as a transmitter, a wide band source supplies a broad band frequency signal to a plurality of filters, time delays, amplifiers, switches and acoustic retinas for applying predetermined signals to the acoustic lenses. When used as a receiver the same plurality of filters, time delays, amplifiers, switches and acoustic retinas act in a complimentary reciprocal fashion in the recovery of signals.

Abstract: Formation of channels for all-round passive sonar systems by the technique of charge-coupled devices. The shift register receives the multiplexed signals of the M transducers forming the listening base of the sonar system. The shift register has different series of sub-contacts, each series corresponding, at one moment, to the signal of one of the transducers. The adding of the weighted signals of one series gives an interpolated signal of the corresponding transducer. The such obtained delayed signals are weighted and added, such obtaining the preformed channels.

Abstract: A discrete transducer array of a plurality of discrete transducer elements, o connected as to achieve a good array directivity pattern with as narrow a beam width as possible for a given side lobe level, or as low a side lobe level as possible for a given beam width, or the most favorable combination of the two. This is to be done with the restriction that there is a discrete array of, say 24, elements that must be shaded discretely, for example by using a series-parallel combination of the elements.

Abstract: There is described a digital sonar receiver having a novel beamformer, own doppler nullifier (O.D.N.), and adaptive time varied gain controller. The beamformer interrogates a multi-element transducer by utilizing an interleaved sampling scheme which samples the elements in the trandsducer array sequentially, in such a fashion that continuous, uniformly spaced samples are obtained. The samples are subsequently converted into digital format, weighed and summed. The O.D.N. eliminates the own ship's doppler effect on the beam output signal resulting in a half beam output signal representative of the target doppler. The O.D.N. offsets the frequency of the beam output signal and a digital generated signal representative of the own ship's doppler. The O.D.N. multiplies these two offsetted signals resulting in a signal lying in each of the sum and difference frequency bands for which the signal lying in the difference frequency band corresponds to the target doppler.

Abstract: An ultrasonic detection system having an array of ultrasonic transducers that are uniformly closely disposed relative to each other such that the active surfaces for transmission or reception are maintained on a straight or curved line. The transducers form radiation or reception beams in a specific direction. Beam orientation is accomplished by selecting a group of transducers from the array and/or respectively applying appropriate phase-shifts to the signals to be fed to each of the transducers or to the signals produced from each of the transducers. Shields are maintained between two adjacent transducers for suppression of sidelobes.

Abstract: An acoustical line array transducer reflector system for producing conical hell radiation patterns. One side of the ground plane reflector of the system is covered with a chloroprene rubber-cork composition. Three transformers in ferrite cup cores are wired to the line array transducer elements.

Abstract: A high resolving power arrangement of transmitting and receiving transducer for arrays the detection of targets in a wave detection system such as sonar. The arrangement includes a transmitting array including two transducers (T.sub.1) and (T.sub.n) transmitting in synchronism or alternatively in phase opposition and a receiving array including transducers T.sub.1, T.sub.2 . . . T.sub.n associated respectively with multiple connector phase shifters (D.sub.1), (D.sub.2) . . . (D.sub.n).

Abstract: A sonar apparatus incorporating steered time compressor means for time coessing and steering hydrophone information. Novel control circuitry enables time compressing and steering operations to be performed in a single storage device.

Abstract: Discrimination of long range targets from short range targets is provided by generating a vertical dipole beam and a narrow uni-directional horizontal beam which may be steered. Targets in the dipole beam are short range targets whose acoustic signals arrive at angles to the horizontal plane, whereas long range targets are those in the horizontal beam, since acoustic signals from long range targets come in on the horizontal plane.

Abstract: Forming and directive control of the beam in a circular sonar array without ime delay or phase shift networks. Predetermined weighting coefficients are used to scale sensor outputs that are summed in an add-only processor to provide a weighted sum output characteristic of target position relative to the main receiving axis of the array.