Choice of Coded Waveform and Correlation Filter for Self-Noise Suppression in Ultrasonic Correlation Systems
Abstract
Various ultrasonic correlation systems have been suggested in the past [1–5] in order to improve the flaw detection capability of ultrasonic NDE systems. These systems use a coded waveform for transmission, and the received signal is processed through a correlation filter. Although, these systems provide considerable improvement in the flaw detection capability, their performance is limited by what is called “self-noise” of the system. This paper discusses the self-noise limitation of conventional ultrasonic correlation systems and presents various approaches for self-noise suppression. Theoretically predicted performance has been verified using detailed computer simulations. Finally, comparison of the performance and practicability of each approach is discussed.
Preview
Unable to display preview. Download preview PDF.
References
- 1.Eric S. Furgason, Vernon L. Newhouse, Nihat M. Bilgutay and George R. Cooper, “Application of Random Signal Correlation Technique to Ultrasonic Flaw Detection”, Ultrasonics, Vol. 13, No. 1, January 1975, Page 11–17.CrossRefGoogle Scholar
- 2.Nihat M. Bilgutay, Vernon L. Newhouse, “Evaluation of Random Signal Correlation System for Ultrasonic Flaw Detection”, IEEE Transactions on Sonics and Ultrasonics, Vol. SU-23, September 1976, Page 329–333.Google Scholar
- 3.Charles M. Elias and T. J. Moran, “A Pseudorandom Binary Noise NDE Ultrasonic Correlation System”, Proceedings of IEEE Ultrasonics Symposium, 1978, page 311–315.Google Scholar
- 4.Charles M. Elias, “An Ultrasonic Pseudorandom Signal-Correlation System”, IEEE Transactions on Sonics and Ultrasonics, Vol. SU-27, No. 1, January 1980, Page 1–7Google Scholar
- 5.B. B. Lee and Eric S. Furgason, “A New Digital Correlation Flaw Detection System”, Journal of Nondestructive Evaluation, Vol. 2, No. 1, 1981, Page 57–63.CrossRefGoogle Scholar
- 6.S. F. Russell, “Theory of Spread-Spectrum Ultrasonic Evaluation ”, Review of Progress in Quantitative NDE, Vol. 13A, pp. 841–846, Bowdoin College, Brunswick, Maine, August 1–6, 1993, eds. D. O. Thompson and D. E. Chimenti (Plenum, New York, 1994).Google Scholar
- 7.J. K. Kayani, S. F. Russell, “Self-Noise Elimination in Ultrasonic Correlation Systems”, Submitted to, 1995 IEEE International Ultrasonics Symposium, November 7–10, 1995, Seattle, Washington.Google Scholar