A prior knowledge based optimal Wiener filtering approach to ultrasonic scattering amplitude estimation

The Measurement and Analysis of Acoustic Noise as a Random Variable

“…stainless steel with an average grain size of 22.5~m (ASTM 8); 2. stainless steel with an average grain size of 62.5~m (ASTM 5); and 3. aluminum with 2% porosity (average pore radius 164~m [1]). Samples 1 and 3 were interrogated with a planar transducer while sample 2 was interrogated with a focused transducer.…”

“…Measured acoustic noise involves the convolution of measurement system effects with a noise related operator [1,2). Acoustic noise can be modeled in the frequency domain as …”

“…These terms are said to be "effective" since they are average or effective operators associated with scattering at a distribution of scattering sites (e.g., scattering from a large number of grains) rather than scattering from a single target [1,2].…”

“…In addition, it is assumed that an estimate of the average power spectra of the noise is available [1][2][3].…”

Theoretical, Simulated, and Experimental Resolution Enhancement of a Transducer by Deconvolution of the Point Spread Function

“…Subbarao [4] showed this type offilter works weil in deconvolving blurry optical images when a known PSF of the Jens is used in the filter. Optimization ofthe parameter r has been subjected to extensive analysis by Neal [5] for the 1-D case and by Dines and Kak [6] for the 2-D case.…”