Nondestructive Imaging of Shallow Buried Objects Using Acoustic Computed Tomography

PDF

Authors
  1. Younis, W.A.
  2. Stergiopoulos, S.
  3. Havelock, D.
  4. Grodski, J.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
The nondestructive three-dimensional acoustic tomography concept of the present investigation combines computerized tomography image reconstruction algorithms using acoustic diffracting waves together with depth information to produce a three-dimensional (3D) image of an underground section. The approach illuminates the underground area of interest with acoustic plane waves of frequencies 200-3000 Hz. For each transmitted pulse, the reflected-refracted signals are received by a line array of acoustic sensors located at a diametrically opposite point from the acoustic source line array. For a stratified underground medium and for a given depth, which is represented by a time delay in the received signal, a horizontal tomographic 2D image is reconstructed from the received projections. Integration of the depth dependent sequence of cross-sectional reconstructed images provides a complete three-dimensional overview of the inspected terrain. The method has been tested with an experimental system that consists of a line array of four-acoustic sources, providing plane waves, and a receiving line array of 32-acoustic sensor. The results indicate both the potential and the challenges facing the new methodology. Suggestions are made for improved performance, including an adaptive noise cancellation scheme and a numerical interpolation technique.
Keywords
Tomography;B-scan;CT (Computed Tomography)
Report Number
DCIEM-SL-2001-094 — Scientific Literature
Date of publication
30 May 2001
Number of Pages
14
Reprinted from
Acoustical Society of America, vol 111,no 5, 2002, p 2117-2127
DSTKIM No
CA021108
CANDIS No
517841
Format(s):
Hardcopy;Document Image stored on Optical Disk

Permanent link

Document 1 of 1

Date modified: