Combining phase and energy detection with mathematical morphology in dual time-frequency representation leads to improved SSP noise robustness

In this paper a fusion algorithm for the detection of specular echoes blurr ed by coloured Gaussian noise is proposed. The phase and energy criteria, c haracteristic of these echoes, are handled separately. First, the detection capabilities of split spectrum (phase) and short time Fourier transform sp ectrogram (energy) are compared theoretically and experimentally. Second, t he new algorithm based on mathematical morphology operators using both time -frequency representations is proposed. In the last part our method is show n to be more robust than absolute minimisation split spectrum processing. ( C) 2001 Elsevier Science B.V. All rights reserved.