A new method for array extension based on minimum redundancy linear array

A new array extension method based on minimum redundancy linear array is proposed to overcome the low hydrophone utilization rate problem and accumulated noise error existing in the most passive synthetic aperture methods based on uniform linear array. The proposed method combines forth-order cumulant with passive synthetic aperture method to extend array using fewer hydrophones. Firstly, successive measurements of a virtual uniform linear array are constructed by applying forth-order cumulant to measurements of minimum redundancy linear array. Then,the array is extended by compensating phase differences using passive synthetic aperture technique. The proposed method not only improves utilization of hydrophones, but also effectively suppresses Gaussian noise. Moreover,it inherits the advantages of the passive synthetic aperture technique. Simulation and experiments results show that this method can generate larger aperture using fewer hydrophones through less iterations and effectively suppress Gaussian noise and reduce computation burden. Moreover, this method can achieved better performance than ETAM method in Gaussian white noise and colored noise environment.