Array aperture synthesis technique for noisy environment

A modified overlap-correlator method of forming a passive synthetic aperture is presented. The previously reported synthetic aperture technique called ETAM uses the overlap of the array in sequential positions to estimate a series of phase correction factors that compensate for the motion of the array over time. In addition, there exists a condition that the overlapped hydrophones among measurements of the moving towed array have the identical position in space. The proposed method does not require such limitations. Moreover, it increases the available number of the extended towed array data using a different set of phase correction factors calculated by the snapshots among measurements. As a result, the mean absolute error performance has been improved in bearing estimation for the array with extended aperture.