Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes

Rais Ahmad, Tribikram Kundu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Defects in underground pipes are detected by applying Gabor transforms on experimental guided wave signals and comparing the experimental group velocity plots with the theoretical group velocity dispersion curves. Gabor transform, which is a powerful signal processing tool, maps a signal into a two-dimensional space of time and frequency. Thus it provides information about both when and at what frequency a signal arrives. Focus of this paper is to study the applicability of cylindrical guided waves to detect defects in underground pipes using Gabor transform. Cylindrical guided waves are generated by piezo-electric transducers. Guided waves are propagated through pipes that are buried in the soil by placing transmitters on one end of the pipes and the receivers on the other end. The recorded signals are then processed using 2-D Gabor Transform or Short Time Fourier Transform (STFT). Gabor transform converts the timeamplitude signal into a time frequency signal which reveals the group velocities hidden in the signal. These experimentally obtained group velocities are then compared with the theoretical velocities for cylindrical pipes embedded in the soil. From the comparison of the theoretical and experimental group velocities, an effort has been made to identify which modes are propagating through the embedded defective pipes and which modes are having difficulty to propagate through the defective pipe wall. From this knowledge pipe wall defects can be detected.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6532
DOIs
StatePublished - 2007
EventHealth Monitoring of Structural and Biological Systems 2007 - San Diego, CA, United States
Duration: Mar 19 2007Mar 22 2007

Other

OtherHealth Monitoring of Structural and Biological Systems 2007
CountryUnited States
CitySan Diego, CA
Period3/19/073/22/07

Fingerprint

Guided electromagnetic wave propagation
Pipe
Defects
group velocity
defects
soils
Group velocity dispersion
Soils
Piezoelectric transducers
piezoelectric transducers
transmitters
signal processing
Transmitters
Fourier transforms
Signal processing
receivers
plots
Mathematical transformations
curves

Keywords

  • Cylindrical guided wave
  • Defect detection
  • Gabor transform
  • Pipe inspection
  • Short time fourier transform
  • Wavelet analysis

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Ahmad, R., & Kundu, T. (2007). Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6532). [65320P] https://doi.org/10.1117/12.715673

Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes. / Ahmad, Rais; Kundu, Tribikram.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6532 2007. 65320P.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Ahmad, R & Kundu, T 2007, Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6532, 65320P, Health Monitoring of Structural and Biological Systems 2007, San Diego, CA, United States, 3/19/07. https://doi.org/10.1117/12.715673
Ahmad R, Kundu T. Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6532. 2007. 65320P https://doi.org/10.1117/12.715673
Ahmad, Rais ; Kundu, Tribikram. / Application of Gabor transform on cylindrical guided waves to detect defects in underground pipes. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6532 2007.
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