Reducing the noise by estimating the acoustic channel and removing active sonar reverberation

Active sonar signals are received by sonobuoy platforms that must not only characterize the signal received but also confirm that no other signal was masked by the arrival of the large signal. If the original signal can be identified, it is possible to estimate the impulse response of the channel over the bandwidth of the original signal. With proper conditioning, it is also possible to then remove the identified signal from the received waveform. It is then easier to search the residual waveform for additional signals of interest. This paper outlines the constraints, methodology, and simulated results of detecting and identifying masked signals in a bottom-limited ocean environment during the simultaneous reception of multiple masked signals. [This paper is based on work supported by the US Navy through the Small Business Innovation Research program.]