High rate acoustic imagery for underwater object classification in dynamic configuration

This paper addresses the problem of underwater imaging using high rate transmitting/receiving waveforms in order to achieve high resolution images in dynamic configurations (i.e. moving objects, fast time varying channels). In terms of signal processing, the problem of high rate transmitting/receiving waveforms, required for achieving high resolution images in dynamic configurations, is to separate between the received signals, knowing that the PRF (Pulse Repetition Frequency) is much higher than in classical imaging techniques. This paper proposes a new transmitting/receiving architecture that combines the basics of the classical imaging principle with the notion of phase diagram based IF (Instantaneous Frequency) law estimation. We point out that the separation of unresolved IF laws in time domain becomes possible in phase diagram domain, making possible the separation of two very close scattering points.