Reconstructing effective ultrasound transducer models via distributed source inversion
This work addresses the problem of characterizing ultrasound transducers for high-fidelity simulation and imaging in ultrasonic testing, representing an incremental advancement in domain-specific modeling.
The paper tackled the challenge of accurately modeling ultrasound wave propagation by proposing a distributed source inversion strategy to reconstruct effective transducer models, which showed close agreement with experimental directivity patterns and improved reconstruction quality in imaging workflows.
Accurate modeling of ultrasound wave propagation is essential for high-fidelity simulation and imaging in ultrasonic testing. A primary challenge lies in characterizing the excitation source, particularly for transducers with large apertures relative to the acoustic wavelengths. In such cases, non-uniform excitation and spatial interference significantly affect the resulting radiation patterns. This paper proposes a distributed source inversion strategy to reconstruct an effective spatio-temporal transducer model that reproduces experimentally measured wavefields. The reconstructed source model captures aperture-dependent phase and amplitude variations without the need for detailed knowledge of the transducer structure. The approach is validated using directivity measurements on an aluminum half-cylinder, where simulations incorporating the reconstructed source model show close agreement with experimental directivity patterns and waveform shapes. Finally, synthetic studies on reverse time migration and full-waveform inversion demonstrate that accurate transducer modeling is critical for the success of simulation-based imaging and inversion workflows and significantly improves reconstruction quality.