Abstract: A circuit coupled to an array antenna, such as a sonar transducer array, for measuring the angle of orientation of an incident wave of radiation is formed of first and second channels coupled to respective portions of the antenna to sense delays between signals of the two channels. A memory retains data of earlier occurring lead and lag measurements. Any subsequent transition from a lead/lag to a lag/lead within a single signal pulse is sensed by a gating circuit which disgards the measurement so as to provide noise immunity.

Abstract: The invention in its preferred embodiment is applied to a spherical assembly of rows of transducer elements arranged in a uniform distribution of elements in each circular row, each row being at a different latitude. The beamforming is accomplished in two steps. First, vertically oriented fan-shaped left and right half beams are formed by a portion of the transducers in each selected row within an elliptical array of transducers. Two adjacent left and right half beams are formed per row. These beams are angularly spaced by the included angle of two adjacent transducers of that row. By a process of interpolation of signals received from a signal source by the left half beams and the right half beams, respectively, resultant left and right half beams with a main response axis in the source azimuth direction are obtained.

Abstract: A sonar system for the detection of signals reflected from a sloping ocean bed in which a sample of the transmitted signal is modified to correspond to the received signal as modified by the sea bottom before both signals are applied to a correlation detector. Modification of the transmitted signal sample is provided by summing incrementally delayed portions of the transmitted signal sample.

Abstract: A communication system for coupling a set of sending stations to a set of listening stations by means of a single communication link employing time compression multiplexing of the messages transmitted from individual ones of the sending stations. A predetermined number of time slots is provided for each of sequentially occurring scans of the sending stations, each slot providing for the transmission of a preset number of data samples. CCD registers are employed with switching circuitry enabling the available slots to be assigned to stations in accordance with the average data rate of a message.

Abstract: A cylindrical array of radiating elements or sonar transducers each of which is coupled by a clipping circuit to a multiply tapped shift register for imparting delays to the signals of the elements for forming a beam of radiant energy. Sidelobes on the radiation pattern are reduced by multiplying the signals of the shift registers by weighting factors prior to their summation for forming a beam, clipped signals serving as unitary factors of positive or negative sign in the multiplication.

Abstract: A sonar system comprising a curved transducer array, typically in the form of a cylinder, in which the transducer elements are arranged in geometrically similar configurations on each of a plurality of planes having symmetry about a common axis. In the presence of an incident beam of radiant energy, the transducer elements are excited by signals having values of delay which vary from transducer to transducer in a regular pattern resulting from the symmetry of the array. This permits the utilization of a relatively small memory for the storing of delay values as a function of the bearing and tilt of the center line of a receiving beam relative to the axis of the array. The delay values are read out of the memory via switching and recycling circuitry to successively apply a sequence of delay values to delay elements coupled to the transducer elements to accomplish a steering of a transmitted or received beam in both elevation and azimuth.