Multi-state beamforming array

Abstract

A sonar system and method of operating a sonar system are disclosed. In one embodiment, the sonar system comprises an array of transducers and a multiplexer configurable into a plurality of states. In one embodiment, the multiplexer, when in a first state, electrically couples a plurality of connections with the plurality of transducers via a first mapping and, in a second state, electrically couples the plurality of connections with the plurality of transducers via a second mapping.

1 . (canceled) 
     
     
         2 . A sonar system comprising:
 a phased array of transducers; and   a multiplexer configured to electrically couple transducers in the phased array of transducers to connections via a plurality of different mappings, the different mappings associated with different element spacings for the same group of transducers in at least one direction in the phased array of transducers.   
     
     
         3 . The system of  claim 2 , wherein different subsets of the same group of transducers of the phased array are associated with different phase-shifts of the same signal. 
     
     
         4 . The system of  claim 2 , wherein the system is configured to transmit a first set of Janus beams having a first beam angle and a second set of Janus beams having a second beam angle from the phased array of transducers, the first beam angle being different than the second beam angle. 
     
     
         5 . The system of  claim 4 , wherein the system is configured to alternatively ping the first set of Janus beams and the second set of Janus beams using the phased array of transducers. 
     
     
         6 . The system of  claim 4 , wherein the first sets of Janus beams and the second set of Janus beams have substantially the same azimuthal angle. 
     
     
         7 . The system of  claim 4 , wherein the system is configured to compensate for errors in Doppler velocity logs using the first set of Janus beams and the second set of Janus beams. 
     
     
         8 . The system of  claim 2 , wherein the phased array of transducers is configured to transmit a set of Janus beams in one of the different mappings and to transmit a single substantially vertical beam in another of the different mappings. 
     
     
         9 . The system of  claim 2 , wherein the different mappings are associated with different element spacings in two substantially orthogonal directions in the phased array of transducers. 
     
     
         10 . The system of  claim 2 , wherein the different mappings comprise at least three different mappings. 
     
     
         11 . The system of  claim 2 , wherein the phased array of transducers is a planar array. 
     
     
         12 . A sonar system comprising:
 an array of transducers; and   a beamformer in communication with the array of transducers and configured to transmit a first set of Janus beams having a first beam angle and a second set of Janus beams having a second beam angle from the same array of transducers, wherein the first beam angle is different than the second beam angle.   
     
     
         13 . The system of  claim 12 , wherein the system is configured to transmit the first set of Janus beams in a first state and to transmit the second set of Janus beams in a second state. 
     
     
         14 . The system of  claim 13 , wherein the system is configured to transmit a single substantially vertical beam in another state. 
     
     
         15 . The system of  claim 12 , wherein the system is configured to alternatively transmit the first set of Janus beams having the first beam angle and the second set of Janus beams having the second beam angle. 
     
     
         16 . The system of  claim 12 , wherein the sonar system comprises an acoustic Doppler current profiler. 
     
     
         17 . The system of  claim 12 , wherein the array of transducers is a planar array. 
     
     
         18 . The system of  claim 12 , wherein the first beam angle is about 22 degrees. 
     
     
         19 . The system of  claim 18 , wherein the second beam angle is about 48.5 degrees. 
     
     
         20 . The system of  claim 12 , wherein the first set of Janus beams has substantially the same azimuthal angle as the second set of Janus beams. 
     
     
         21 . The system of  claim 12 , wherein the first set of Janus beams comprises three beams for measuring velocity. 
     
     
         22 . The system of  claim 21 , wherein the first set of Janus beams comprises another beam for redundancy. 
     
     
         23 . The system of  claim 12 , wherein the array of transducers comprises a phased array of transducers. 
     
     
         24 . A method of operating a sonar system, the method comprising:
 receiving first acoustic data corresponding to a first set of Janus beams at an array of transducers;   changing an element spacing in the array of transducers; and   receiving second acoustic data corresponding to a second set of Janus beams at the same array of transducers, wherein the second acoustic data is received when transducers of the array have a different element spacing than the same transducers had when the first acoustic data is received.   
     
     
         25 . The method of  claim 24 , wherein changing comprises functionally combining groups of transducers of the array of transducers. 
     
     
         26 . The method of  claim 24 , further comprising transmitting the first set of Janus beams from the array of transducers. 
     
     
         27 . The method of  claim 24 , wherein the sonar system is configured to generate dual sets of Janus beams having different beam angles with respect to a central axis. 
     
     
         28 . The method of  claim 27 , wherein the dual sets of Janus beams have substantially the same azimuthal angle.