Abstract: A broadband sonar system is configured to be coupled to a narrow band sonar sensor array having a plurality of sensor groups configured in subarrays. Each of the sensor groups within a subarray is spaced equidistantly from adjacent sensor groups within the same subarray. The sonar system includes a plurality of signal compensation filters, each being coupled to a respective one of the sensor groups for receiving signals from the respective sensor group and weighting the signals to generate respective output signals. The weighting of the signal from a first sensor group having a first SNR is greater than the weighting for the signal from a second sensor group that has a second SNR when the first SNR is greater than the second SNR, so as to maximize the SNR of the array. At least one broadband beamformer is coupled to the signal compensation filters for combining the output signals for determining ranges to targets.

Abstract: A broadband sonar system in which a broadband output from a conventional narrowband sonar sensor array is used to capture broadband acoustical input signals. A single broadband beamformer receives the input from each of the sensors (such as hydrophones) of the array. The broadband output signal from each sensor of a particular subarray is coupled to a corresponding one of a plurality of first filters. Each first filter emphasizes those frequencies of each subarray which have the least noise. In addition, the output is attenuated for frequencies below the design frequency, with lower frequencies being attenuated to a greater degree than higher frequencies. A plurality of second and third filters, each corresponding to a subarray, are provided to compensate for the effects of the frequency and sensor spacing on the signal as the beam rotates.