Patent ID: 6310832
Filing Date: 2001-10-30
Classification: G01S

Abstract:
A sonar tracking system for tracking the signal provided by a signal source comprising:a plurality of transducers arranged in a plurality of circular rows, each transducer adapted to receive a signal from a signal source, and each transducer of a row being spaced from its adjacent transducer by an included angle measured from the center of said circular row;a row beamforming means combining the output of selected adjacent transducers in a row for providing a pair of beams, each pair providing a left-half and a right-half beam signal having main response axes in predetermined azimuthal directions and a declination/elevation direction, said azimuthal directions differing in angle by the included angle of the transducers of the row;interpolating means connected to the output of said row beamforming means for combining the left half beam signal and the right-half beam signal in response to the signal from said source to provide an interpolated beam providing an interpolated right- and left-half beam signal with its main response axis centered on said signal source;a plurality of said row beamforming means and its associated said interpolating means, each said row beamforming means and said associated interpolating means connected to selected adjacent transducers of one of said plurality of adjacent rows;a column beamforming means comprising a first and second column beamforming means;said first column beamforming means responsive to the interpolated right half beam signals of selected rows of transducers to form upper- and lower-right half beam signals;said second column beamforming means responsive to the interpolated left half beam signals of selected rows of transducers to form upper- and lower-left half beam signals;said upper- and lower-right and left half beams forming quadrant beams having a main response axis; andmeans responsive to said upper and lower right and left half beam signals to provide error signals indicative of the angular direction by which said main response axis is to the right or left and up or down from said signal source.