Beam space weighted subspace fitting algorithm

The sensor space high resolution Weighted Subspace Fitting (WSF) algorithm is expanded into beam space in this paper. Beam space WSF algorithm uses beam outputs of array which can be regarded as the outputs of an virtual array having the same number of elements as the beam number to estimate target directions. In most underwater acoustic systems, the number of beams used for determining the direction of arrival is usually considerably less than that of the sensors, so the computation burdensome is decedent. Computer simulation results show that the beam space WSF algorithm retains the super performance of the sensor space WSF algorithm when applied to the beam outputs of some practical acoustic-receiving array.

A subspace fitting algorithm of acoustic vector sensor array and corresponding matrix pre-filter design

In order to ease the pass-band response distortion of the matrix pre-filter,a simple approach for designing matrix spatial filter is proposed,which minimizes the sum of the k maximal distortion norm（k is the number of the constraint points）within the pass-band,while constraining the filter response within the stop-band.Considering the costly amount of calculation of the high-resolution methods,an algorithm with small amount of calculation based on matrix pre-filtering and subspace fitting using acoustic vector array（MF-VSSF）is proposed.Through joint processing of signal subspace of both pressure and particle velocity,the pre-filtering matrix and the signal subspace is decreased to M-dimensional（M is the number of array-element）,hence reduces the time-consumption of the matrix pre-filter design and DOA searching.Simulation results show that,the method offers the same performance as MUSIC with pre-filtering,but has much lesser amount of calculation.Moreover,the designed prefilter can efficiently suppress the interference in the stop-band and improve the estimation and resolution performance of successive DOA estimators.