Target detection method for reverberant environments in continuous-wave active sonar system based on group multichannel nonnegative matrix factorization

In the underwater environment, the active sonar system emits an acoustic wave and receives echo signals to detect a target. However, the echo signals consist of not only the echo from the target but also the reverberation from scatterers. If the target has a low speed, the detection problem is more difficult because the target echo is interfered by the reverberation severely. In this paper, the target detection method for the reverberant environment is developed based on multichannel nonnegative matrix factorization. To extract the target echo signal mixed with reverberations, received signal is transformed into bearing-time-frequency domain, and analyzed into bearing, frequency, and temporal basis by the multichannel nonnegative matrix factorization. The simulation was performed to evaluate the proposed method, and the result shows that the proposed method has good detection performance in the simulated reverberant environments.