Iterative inverse beamforming algorithm and its application in multiple targets detection of passive sonar

With the increasing of detection ability of passive sonar, the weak signal detection problem in multiple interferences becomes more and more important. In the time/bearing record (TBR) display of sonar detection, when there exist multiple interferences traces, the identification of weak signal is difficult or impossible. The adaptive noise cancellation technique provides the theoretical basis of suppressing strong interferences. But the solution for finding the steady-state optimum filter matrix is quite difficult due to the real time calculation of inverse matrix of input data correlation matrix.
The iterative inverse beamforming (IBF) algorithm for solving the optimum filter matrix is derived in this paper, by which, the optimum filter can be finally expressed as a series of sum of simple matrix of input data.
Based on the Mgorithm proposed in this paper, some examples of at sea experiment are provided. The strong interferences are canceled and the weak signal is emerged, even it is not appeared in conventional beamforming (CBF) processing.