Acoustic backscatter eturns measured with a vertical source and horizontal receiving array are beamformed and charted to respective scattering sites on the western flank of the Mid-Atlantic Ridge (MAR). Well-defined patterns of high-level backscatter esembling bottom morphology occur within the direct path and at convergence zone ranges. Measured backscatter is compared with modeled two-way tra...

Acoustic backscatter mosaics derived from multibeam and sidescan sonars are often used to estimate seafloor type and composition, which are important parameters in the description of benthic habitats. However, due to limitations of the mosaicking technique, backscatter mosaics are restricted in their capacity to unambiguously discriminate seafloor properties. A more adequate technique to charac...

OBJECTIVE As are the attenuation coefficient and sound speed, the backscatter coefficient is a fundamental ultrasonic property that has been used to characterize many tissues. Unfortunately, there is currently far less standardization for the ultrasonic backscatter measurement than for the other two, as evidenced by a previous American Institute of Ultrasound in Medicine (AIUM)-sponsored interl...

the present study investigates the crystal preferred orientation (cpo) of quartz crystals in psammitic rocks to ascertain the deformationmechanism using electron backscatter diffraction (ebsd) on quartz crystals from north of the renvyle-bofin slide (rbs) nearletterfrack in western ireland. complete crystallographic orientations were determined for several thousand individual quartz crystalsin ...

PURPOSE To develop a method for removing the effect of support arm backscatter from Varian electronic portal imaging devices (EPIDs), improving the dosimetric abilities of the imager. METHODS A physical, kernel based model of the backscatter signal produced during an exposure was developed. The model parameters were determined through an optimization process, comparing measured images without...

Backscatter and attenuation variations are essential contrast mechanisms in ultrasound B-mode imaging. Emerging quantitative ultrasound methods extract and display absolute values of these tissue properties. However, in clinical applications, backscatter and attenuation parameters sometimes are not easily measured because of tissues inhomogeneities above the region-of-interest (ROI). We describ...

In this paper, measurements and models for the polarimetric backscatter response of various point targets on roads and road surface faults is presented. Of particular interest are debris and faults that could lead to fatal accidents and damage of property. A desired safety feature for automotive radar sensors is the capability of detecting such debris and faults. The detectability of a point ta...

BACKGROUND Accumulation of lipids within coronary plaques is an important process in disease progression. However, gray-scale intravascular ultrasound images cannot detect plaque lipids effectively. Radiofrequency signal analysis could provide more accurate information on preclinical coronary plaques. METHODS We analyzed 29 zones of mild atheroma in human coronary arteries acquired at autopsy...

The Cloud Physics Lidar (CPL) is a threewavelength, polarization-sensitive elastic backscatter lidar that flies aboard NASA’s high-altitude ER2 research aircraft. This work presents spatial and optical analyses of the combined cirrus cloud measurements acquired by CPL during eight separate field campaigns occurring from 2002 to 2007. Particular attention is given to the retrieval and characteri...