Ultrasonic Imaging in Solids Using Wave Mode Beamforming
| Autor: | Francesco Lanza di Scalea, Thompson V. Nguyen, Simone Sternini |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Beamforming
Engineering Acoustics and Ultrasonics business.industry Aperture Matched filter Acoustics 02 engineering and technology 01 natural sciences 020303 mechanical engineering & transports Optics 0203 mechanical engineering Compounding Nondestructive testing 0103 physical sciences Wave mode Array gain Ultrasonic sensor Electrical and Electronic Engineering business 010301 acoustics Instrumentation |
| Zdroj: | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. 64:602-616 |
| ISSN: | 0885-3010 |
| Popis: | This paper discusses some improvements to ultrasonic synthetic imaging in solids with primary applications to nondestructive testing of materials and structures. Specifically, the study proposes new adaptive weights applied to the beamforming array that are based on the physics of the propagating waves, specifically the displacement structure of the propagating longitudinal (L) mode and shear (S) mode that are naturally coexisting in a solid. The wave mode structures can be combined with the wave geometrical spreading to better filter the array (in a matched filter approach) and improve its focusing ability compared to static array weights. This paper also proposes compounding, or summing, images obtained from the different wave modes to further improve the array gain without increasing its physical aperture. The wave mode compounding can be performed either incoherently or coherently, in analogy with compounding multiple frequencies or multiple excitations. Numerical simulations and experimental testing demonstrate the potential improvements obtainable by the wave structure adaptive weights compared to either static weights in conventional delay-and-sum focusing, or adaptive weights based on geometrical spreading alone in minimum-variance distortionless response focusing. |
| Databáze: | OpenAIRE |
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