Accession Number:

ADA582757

Title:

Synthetic Aperture Acoustic Imaging of Non-Metallic Cords

Descriptive Note:

Conference paper

Corporate Author:

CATHOLIC UNIV OF AMERICA WASHINGTON DC DEPT OF MECHANICAL ENGINEERING

Report Date:

2012-04-01

Pagination or Media Count:

10.0

Abstract:

This work presents a set of measurements collected with a research prototype synthetic aperture acoustic SAA imaging system. SAA imaging is an emerging technique that can serve as an inexpensive alternative or logical complement to synthetic aperture radar SAR. The SAA imaging system uses an acoustic transceiver speaker and microphone to project acoustic radiation and record backscatter from a scene. The backscattered acoustic energy is used to generate information about the location, morphology, and mechanical properties of various objects. SAA detection has a potential advantage when compared to SAR in that non-metallic objects are not readily detectable with SAR. To demonstrate basic capability of the approach with non-metallic objects, targets are placed in a simple, featureless scene. Nylon cords of five diameters, ranging from 2 to 15 mm, and a joined pair of 3 mm fiber optic cables are placed in various configurations on flat asphalt that is free of clutter. The measurements were made using a chirp with a bandwidth of 2-15 kHz. The recorded signal is reconstructed to form a two-dimensional image of the distribution of acoustic scatterers within the scene. The goal of this study was to identify basic detectability characteristics for a range of sizes and configurations of non-metallic cord. It is shown that for sufficiently small angles relative to the transceiver path, the SAA approach creates adequate backscatter for detectability.

Subject Categories:

  • Cybernetics
  • Acoustic Detection and Detectors
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE