A natural extension of the acoustic time-reversal mirror (TRM) is investigated where receive array signals are backpropagated to an arbitrary source location. First, large time-bandwidth product (TB), broadband signals propagating from a probe source to the array are processed iteratively by a model-based matched filter (MBMF) receiver in searching for the environmental parameters that best correspond to the measured acoustic-impulse responses. The process ends when most of the time-spread energy across the array is recombined (processing gain). Second, the resulting acoustic-channel model is used to synthesize the transmit signals that will focus their energy at the desired range and depth (the virtual source). The procedure overcomes the noise and reverberation limitations inherent to the TRM operation. The at-sea, focusing performances of a model-based TRM were predicted from related MBMF experiments: range-depth localization of a distant towed source in a duct (west sardinia 89\N90) and bottom geoacoustic characterization in shallow water (yellow shark 94\N95) [Hermand , IEEE J. Oceanic Eng. , 447–465 (1993); , 41–66 (1999)]. Simulation results using yellow shark 94, large TB, broadband vertical array data will be compared with trm 96\N97 experimental results [Hodgkiss , J. Acoust. Soc. Am. , 1597–1604 (1999)] obtained along the same transect.
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