Abstract: Signals entered from receiving transducer elements of 160 channels are multiplexed into 10 signal lines by 10 multiplexers. Each of 10 A/D converters converts the signals of 16 channels from analog from into digital form. The multiplexers are switched with synchronized switching timing to produce 10 pieces of sample data strings with the same timing. 160 pieces of sample data sampled in a steplike form are shifted in phase according to an oblique-line sampling scheme. The signal of the same channel is sampled twice with a phase delay of 90° so that the signal can be converted into complex-valued sample data without increasing the number of processing circuits.

Abstract: An underwater sonar measuring method using synthetic aperture technique which radiates an ultrasonic signal to targets by a transmission transducer unit (1B), receives echo signals reflected by the targets by moving reception transducer units (1A, 1B, 1C) at a plurality of points, adjusts a plurality of signals received in phase and combines the resultant phase-shifted signals. The reception transducer units are moved over a distance less than the length "L" of the transmission transducer unit during a period for an ultrasonic signal going to and returning from a target. The signals received and phase-combined during this period are multiplyed by the radiated signals so that there are eliminated grating lobes appearing on both sides of the main lobe when an aperture synthesis is performed, and thus a high resolution measurement is made.

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: A scanning sonar system for detecting objects and displaying them on a circular screen and producing audible signals coordinated with the visual signals indicating the detection of an object.

Abstract: An ultrasonic detection system which includes means for the transmission of signals in all directions, a circular array of transducers arranged at uniform intervals, means for producing output signals from spaced transducers and then sequentially combining outputs from sets of adjoining transducers to produce a plurality of received signals for display on indicating means.

Abstract: A plan position indicating system which includes a display screen and means for indicating on the screen the tilt angle of the transmitted beam and received signals to enable measurement not only of direction and distance but also the horizontal and vertical components thereof.

Abstract: Apparatus for controlling the angular direction of wave transmission of an ultrasonic transmitting system having a plurality of uniformly spaced transducers which includes means for successively shifting the phase of the signals emitted by each transducer and providing means for controlling the magnitude of the phase shift to alter the angle of transmission.