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Robust Signal Processing for Material Noise Suppression in Ultrasonic Nondestructive Testing

  • Lars Ericsson
  • Tadeusz Stepinski

Abstract

Ultrasonic nondestructive inspection of materials is often limited by the presence of backscattered echoes from the material structure, known as material or grain noise. The material noise can be difficult to distinguish from flaw echoes because their spectra overlap to a large extent. Due to the overlapping, application of conventional linear filters is generally not adequate for attenuating this type of noise. However, a suitable choice of the inspection frequency will cause the grain response to be considerable more noncoherent than the flaw response. This property arise from the fact that the material noise can be considered as an interference pattern made up of unresolved scatterers, while the flaw echoes will bear more resemblance to specular reflections. The implication of this difference is that the material noise can be suppressed by means of frequency diversity techniques which take advantage of its noncoherent nature.

Keywords

Extraction Algorithm Ultrasonic Signal Split Signal Gaussian Window Ultrasonic Inspection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press, New York 1993

Authors and Affiliations

  • Lars Ericsson
    • 1
  • Tadeusz Stepinski
    • 1
  1. 1.Department of Technology Circuits and SystemsUppsala UniversityUppsalaSweden

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