Significance of envelope detection in underwater acoustic imaging systems

This paper deals with the significance of the envelope detection operation, commonly performed on the output signals generated by a sonar imaging system, before of the visualisation. Although imaging systems are often linear processes, envelope detection destroys phase information, thus producing a nonlinear contribution. Within this paper, the relative importance of the nonlinear contribution is evaluated, in a general way, and its incidence in real sonar systems has been analysed, in a practical way, by performing several simulations. Simulations results have pointed out a considerable incidence of such nonlinearities on the quality of obtained images.