1. A method for characterizing a biological material from acoustic signals, comprising: synthesizing individual orthogonal coded waveforms to form a composite waveform for transmission toward a biological material of interest, wherein the synthesized individual orthogonal coded waveforms correspond to distinct frequency bands and include one or both of frequency-coded or phase-coded waveforms; transmitting a composite acoustic waveform toward the biological material of interest, wherein the transmitting includes transducing the individual orthogonal coded waveforms into corresponding acoustic waveforms to form the composite acoustic waveform; receiving returned acoustic waveforms that are returned from at least part of the biological material of interest corresponding to at least some of the transmitted acoustic waveforms that form the composite acoustic waveform; and processing the received returned acoustic waveforms to produce range-Doppler data of at least part of the biological material of interest.