Display and interpretation of a time-spread underwater acoustic channel´s bandlimited impulse response

A useful technique for displaying the complex envelope of the band limited impulse response of a time-varying channel is presented. This impulse response measurement is also the approximate delay spread function of the channel. This is an illustration of a display of a complex-valued function of two independent variables (e.g. time and time-delay). The utility of the display is emphasized by propagation examples from the MIMI experiment [5] in the Straits of Florida. Channel characteristics readily observed from a twelve hour display are delay spread, multipath structure, individual path propagation time, and correlation of channel structure with scalar measurements of the channel.