Ultrasonic backscatter of myocardial walls is directly related to the morphometrically evaluated collagen content in humans. The integrated backscatter is also increased in hypertrophic cardiomyopathy, whereas it gives normal values in the physiological hypertrophy of elite athletes. We assessed the quantitatively evaluated myocardial reflectivity in 46 mild to moderate, clinically uncomplicate...

The dry snow zone is the largest component of the Greenland ice sheet and is identified as the region that experiences no annual melt. Therefore, radar backscatter (σ) is expected to be relatively constant over time within the dry snow. However, annual variation was discovered in QuikSCAT data. This paper tests the hypothesis that annual variation in backscatter is caused by changes in permitti...

Theoretical acoustic models of fish are used to explain variability in backscatter measurements, improve estimation of target size, and improve target recognition and discrimination among acoustic targets. Acoustic backscatter models that incorporate fish morphology potentially provide more realistic predictions of echo amplitudes than models that approximate morphology using simple geometric s...

Implementation of an algorithm for the automated determination of the magnitude and time delay of the cardiac cycle-dependent variation of integrated backscatter is reported. This algorithm has been implemented in the experimental firmware of a commercially-available echocardiographic imaging system. Integrated backscatter and the cardiac cycle-dependent variation (cyclic variation) of integrat...

Synthetic aperture radar (SAR) imagery from the sea can contain ships and their ambiguities. The ambiguities are visually identifiable due to their high intensities in the low radar backscatter background of sea environments and can be mistaken as ships, resulting in false alarms in ship detection. Analysing polarimetric characteristics of ships and ambiguities, we found that (a) backscattering...

The dependence of acoustic backscatter variations on sediment grain-size distribution is examined using a combined analysis of 95 kHz side-scan data and approx. 300 grab samples from the New Jersey margin. We show that, under well-controlled circumstances, an unprecedented degree of correlation can be obtained between backscatter intensity and mean grain size. However, backscatter is disproport...

The high frequency backscatter from cells with a nucleus to cell volume ratio of 0.50 cannot be adequately modeled as a homogeneous sphere. It was hypothesized that the cytoplasm of such cells is of fluid nature. This work attempts to model the ultrasound backscatter (10-62 MHz) from some non-nucleated biological specimens. This was done by measuring the backscatter response from individual sea...

Natural land targets for ERS RA-1 backscatter, including the Simpson desert, the Takla Makan, parts of the Sahara and the Arabian desert, have previously been identified and modelled using ERS-1 Geodetic Mission and Tandem Mission data. These have been used to perform cross-calibration of ERS-1/2 ice and ocean mode altimeter σ0. The advent of the Envisat RA-2 provides an opportunity to study th...

The backscatter from ocean waves measured by scatterometers is primarily determined by the speed and direction of near-surface wind, while other influences (temperature, salinity, swell, etc.) appear to be secondary effects. A complete theoretical geophysical model, incorporating all influences on the backscatter, appears beyond the current state of science; empirical estimates of the wind-back...

This paper presents a new analysis method for locating the focus and estimating the size of the focus of the backscatter light of a Lidar system. The formula for calculating the uncertainty of the location of the focus of backscatter light of a Lidar system is given, and the estimation of the size of the focus is also presented. This calculation coincides with the analysis result of ZEMAX softw...