An optimal subspace projection for signal detection in noisy environment

Detecting useful information in the underwater domain has taken an important place in many research works. But this problem is not easy to solve because of the large diversity of acoustic sources in the underwater medium. To illustrate this point, let us consider separately two main kinds of information. On the one hand, artificial signals coming from human activities (communication, imaging, detection, ...) and, on the other hand, natural signals due to biological or seismic activities. This non exhaustive enumeration shows that underwater information is very diverse and because all entities live together, the information coming from each one is necessarily interacting with all the others. So one can easily imagine that numerous interaction problems between these two kinds of information arise. In this paper, we propose to answer the problem of signal detection in noisy environment using an optimal subspace projection. The proposed method is confronted to real data, with signals resulting from underwater acoustic measurements: several whale echoes (the signal of interest to be detected) and a superposition of various marine acoustic signatures.