Spectral Redundancy in Characterizing Scatterer Structures from Ultrasonic Echoes
نویسندگان
چکیده
Broadband ultrasonic back-scattered energy contains information regarding material structures from which it was scattered. Signal processing techniques use characteristic changes in the back-scattered signals to detect scatterers or reflectors that represent flaws and impurities within a manufactured part. A-scans from materials such as stainless steel, titanium, and composites comprised of dense layers or fibers, exhibit significant scattered energy at positions throughout the material. Consequently, signal processing methods are needed to filter out signals characteristic of normal material echoes and enhance echoes from defective structures.
منابع مشابه
Ultrasonic scatterer structure classification with the generalized spectrum
Ultrasonic back-scattered echoes resulting from the structures within a scanned object contain information of potential diagnostic value. The most common nondestructive evaluation (NDE) techniques use large-scale changes in the back-scatterer coefficients to reveal boundaries between materials with different density/elasticity properties or defects in homogenous material regions. Less common te...
متن کاملA theoretical comparison of attenuation measurement techniques from backscattered ultrasound echoes.
Accurate characterization of tissue pathologies using ultrasonic attenuation is strongly dependent on the accuracy of the algorithm that is used to obtain the attenuation coefficient estimates. In this paper, computer simulations were used to compare the accuracy and the precision of the three methods that are commonly used to estimate the local ultrasonic attenuation within a region of interes...
متن کاملQuantitative Ultrasonic Characterization of Diffuse Scatterers in the Presence of Structures That Produce Coherent Echoes By
Quantitative ultrasound (QUS) techniques that parameterize the backscattered signal power spectrum have demonstrated significant promise for ultrasonic tissue characterization. Some QUS parameters, including the effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) that can be used for disease detection and diagnosis, require the assumption that the examined medium c...
متن کاملMean-scatterer spacing estimates with spectral correlation.
An ultrasonic backscattered signal from material comprised of quasiperiodic scatterers exhibit redundancy over both its phase and magnitude spectra. This paper addresses the problem of estimating mean-scatterer spacing from the backscattered ultrasound signal using spectral redundancy characterized by the spectral autocorrelation (SAC) function. Mean-scatterer spacing estimates are compared for...
متن کاملQuantitative Analysis of Noise Influence on the Detection of Scatterer Concentration by Nakagami Parameter
The Nakagami statistical parameter has been demonstrated to be capable of detecting the variation of scatterer concentration in a biological tissue. The accuracy and sensitivity of the Nakagami parameter would be varied by the quality of ultrasonic backscattered signals, which is further affected by noise interference. For this reason, the experimental measurements and two-dimensional computer ...
متن کامل