Dynamic acoustical imaging systems with reconfigurable transceiver arrays and probing waveforms

Abstract

The data-acquisition format of traditional acoustical imaging systems has been operating with structured transceiver arrays and predetermined illumination waveforms. The fixed physical array configurations have been largely linear or planar, for computation simplicity. The conventional systems started with the coherent mode with narrow-band illumination. The coherent illumination waveforms were then replaced by wideband signals to operate in the pulse-echo format for the improvement of range resolution. This paper presents the functionalities of reconfigurable acoustical imaging systems with FMCW probing waveforms, and the equivalence to the conventional modalities. The reconfigurable configuration is applied to both the transceiver aperture arrays and the probing signals for the enhancement of the resolving capability. The reconfigurable array allows us to actively optimize the aperture coverage for superior resolution. To achieve reconfigurable illumination waveforms, programmable stepped-frequency FMCW signaling modality is employed. The presentation of this paper includes the algorithm structure, range estimation, and frequency editing, and of special interest and importance, the detection and imaging of time-varying targets.