Effective Density Estimators Based on the K Distribution: Interest of Low and Fractional Order Moments

• Published in: Ultrasonic imaging Vol. 20; no. 4; pp. 243 - 259
• Main Authors: Ossant, Frédéric, Patat, Frédéric, Lebertre, Matthias, Teriierooiterai, Marie-Laure, Pourcelot, Léandre
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.10.1998; Dynamedia
• Subjects: Acoustic signal processing; Acoustical measurements and instrumentation; Acoustics; Biological and medical sciences; Computer Simulation; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Humans; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Miscellaneous. Technology; Models, Statistical; Phantoms, Imaging; Physics; Ultrasonic investigative techniques; Ultrasonography; speckle statistics; K distribution; tissue characterization; scattering; statistical moments; Effective density; Tissue; Signal envelope; Density measurement; Statistical moment; Echography; Testing equipment; Signal processing; Measurement method; Experimental study; Random medium; Ultrasound; Signal to noise ratio
• ISSN: 0161-7346; 1096-0910
• DOI: 10.1177/016173469802000402

The K distribution is an efficient model to the nonRayleigh statistics of the envelope of backscattered signals in random media. This modeling leads to estimate a parameter of effective density by means of the calculation of statistical moments of the envelope signal. In this study, we propose a mathematical analysis of an effective density estimator previously used and based on superior order moments. In order to improve the effective density estimate, we propose several estimators based on low and fractional order moments. The performances of these estimators are evaluated both with simulated signals and in an experimental context with synthetic foams. Estimators based on low and fractional moments appear to be more robust than superior moment-based estimator and an improvement of the spatial resolution of the estimate can be obtained. Results also confirm the capability of the effective density parameter to characterize the spatial distribution of scattering structures.