A vertical beamforming design approach for increased area coverage rate for synthetic aperture sonar

The authors present a design approach for increasing the area coverage rate for a bottom mapping synthetic aperture sonar (SAS). The approach uses dual acoustic data channels which are established by vertical beamforming from a single phase-shifted transducer array. An SAR (synthetic aperture radar) image quality criterion known as the ambiguity ratio, which affects image contrasts, is applied to the SAS problem to establish design constraints for beam patterns and pulse repetition frequency. Relationships between transducer array size, spacing of individual elements of the array, sonar Doppler sampling rates, and geometry parameters are presented for an illustrative data collection scenario. Achievement of increased area coverage rate by a factor of 3 is demonstrated within the constraints imposed by the image quality performance criterion