Location

Seattle, WA

Start Date

1-1-1996 12:00 AM

Description

In ultrasonic nondestructive evaluation (NDE), grain noise corrupts the scattered wave field from a flaw in a polycrystalline material. Many probabilistic approaches associated with flaw detection and characterization utilize stochastic models in which grain noise is assumed uncorrected and zero-mean Gaussian distributed. Typically, the Gaussian assumptions is justified via heuristic arguments based on the central limit theorem. This paper presents the kurtosis test and the Shapiro-Wilk W test as methods to quantitatively test time domain noise ensembles for deviations from Gaussian statistics. We will establish, through the application of these hypothesis tests to grain noise, a quantitative tool which can be used to consider “how Gaussian” grain noise signals must be for Gaussian noise based signal processing procedures to out perform alternative approaches.

Volume

15A

Chapter

Chapter 3: Signal Processing and Image Analysis

Section

Signal Processing

Pages

789-796

DOI

10.1007/978-1-4613-0383-1_103

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Testing for Nongaussian Fluctuations in Grain Noise

Seattle, WA

In ultrasonic nondestructive evaluation (NDE), grain noise corrupts the scattered wave field from a flaw in a polycrystalline material. Many probabilistic approaches associated with flaw detection and characterization utilize stochastic models in which grain noise is assumed uncorrected and zero-mean Gaussian distributed. Typically, the Gaussian assumptions is justified via heuristic arguments based on the central limit theorem. This paper presents the kurtosis test and the Shapiro-Wilk W test as methods to quantitatively test time domain noise ensembles for deviations from Gaussian statistics. We will establish, through the application of these hypothesis tests to grain noise, a quantitative tool which can be used to consider “how Gaussian” grain noise signals must be for Gaussian noise based signal processing procedures to out perform alternative approaches.