Improving the Performance of a Vector Sensor Line Array by Deconvolution

Deconvolution applied to conventional beamforming (CBF) has been demonstrated for a uniform line array and circular array of hydrophones resulting in much improved performance than CBF. However, the existing Richardson-Lucy (R-L) method is limited to arrays with a shift-invariant beam pattern. An extended R-L deconvolution algorithm is proposed in this paper so that the deconvolved CBF can be applied to arrays with a shift-variant beam pattern, such as a vector sensor line array. The new extended R-L algorithm uses the predefined beam pattern from all steering angles to replace the shift of the point spread function. It is shown with both simulated and sea data that deconvolved beam power yields a narrower beamwidth, higher peak-to-sidelobe ratio, higher left/right suppression ratio, and higher directivity index or array gain than CBF. The extended R-L algorithm is shown to yield superior performance, particularly at low signal-to-noise ratios, compared with other deconvolution algorithms, and much less computation time for the same number of iterations, which are of practical importance.