Location

Brunswick, ME

Start Date

1-1-1992 12:00 AM

Description

Ultrasonic reflection imaging has become an important tool in NDE [1,2,3]. The lateral resolution of such images is limited by the aperture size of the transducer, while the depth resolution is limited by the pulse length. In addition, for a given aperture diameter, the lateral resolution degrades with depth as given by the Rayleigh criterion. In this paper we discuss a method to increase the effective aperture through aperture synthesis. Waveform data, collected from a scanned transducer focused near the surface of the sample, is coherently processed to yield a synthesized aperture which can be focused to any depth with constant resolution. The synthetic aperture method allows efficient volume inspection by trading off scan time with processing time, the latter of which is constantly decreasing with increasing computing power.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

11A

Chapter

Chapter 3: Interpretive Signal Processing and Image Reconstruction

Section

Imaging and Inversion Techniques

Pages

813-820

DOI

10.1007/978-1-4615-3344-3_104

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Ultrasonic Synthetic-Aperture Holographic Imaging†

Brunswick, ME

Ultrasonic reflection imaging has become an important tool in NDE [1,2,3]. The lateral resolution of such images is limited by the aperture size of the transducer, while the depth resolution is limited by the pulse length. In addition, for a given aperture diameter, the lateral resolution degrades with depth as given by the Rayleigh criterion. In this paper we discuss a method to increase the effective aperture through aperture synthesis. Waveform data, collected from a scanned transducer focused near the surface of the sample, is coherently processed to yield a synthesized aperture which can be focused to any depth with constant resolution. The synthetic aperture method allows efficient volume inspection by trading off scan time with processing time, the latter of which is constantly decreasing with increasing computing power.