E r young (< 15 years old) lobloUy pine stands at Duke Forest (North Carolina, USA), when the ground was wet, the observed ERS-1 SAR backscatter from short-grass fields of 0.05 kg /m 2 biomass was >~ the backscatter from the stands, and there was no significant correlation between the backscatter and biomass (r 2 = 0.19). Under dry soil conditions, the backscatter increased about 2-3 dB as the ...

Integrated ultrasonic backscatter has been related to collagen deposition in fibrotic myocardium. The purpose of our study was to measure the integrated ultrasonic backscatter in the right and left ventricles of 10 normal freshly excised canine hearts and five normal formalin-fixed human hearts. A 2.25 MHz, 50% fractional bandwidth transducer was positioned at the transducer focal distance from...

Systematic characterization of the scattering behavior of traffic targets, clutter, and their associated interactions are required in order to design and assess the performance of millimeter-wave-based sensors for automated highway system (AHS) applications. In this paper, the polarimetric radar backscatter response of various road surfaces is investigated both theoretically and experimentally....

In animal hearts, the magnitude of integrated ultrasonic backscatter is increased in fibrotic myocardium. Our purpose in this study was to quantitate the relationship between ultrasonic backscatter and collagen deposition in 10 excised human hearts with old infarcts. A 2.25 MHz, 50% fractional bandwidth transducer was positioned at the transducer focal distance from the epicardium of each speci...

OBJECTIVES This study was undertaken to differentiate hypertrophic cardiomyopathy from hypertensive hypertrophy using a newly developed M-mode format integrated backscatter imaging system capable of calibrating myocardial integrated backscatter with the power of Doppler signals from the blood. BACKGROUND Myocardial integrated ultrasound backscatter changes in patients with hypertrophic cardio...

Recent theoretical and experimental advances have shed light on the existence of so-called "perfectly transmitting" wavefronts with transmission coefficients close to 1 in strongly backscattering random media. These perfectly transmitting eigen-wavefronts can be synthesized by spatial amplitude and phase modulation. Here, we consider the problem of transmission enhancement using phase-only-modu...

Polar mesospheric clouds (PMCs) were observed by a ground-based Fe Boltzmann temperature lidar for 65 h on 17-19 and 24-26 January 2000 above the geographic South Pole. The mean PMC backscatter ratio, volume backscatter coetficient, total backscatter coetficient, layer centroid altitude, and layer rms width are 53.5, 2.9x10 -9 m-Xsr -x, 4.3x10 -6 sr -x, 85.37 km, and 0.78 km, respectively. Stro...

Ambient backscatter communication technology has been introduced recently, and is then quickly becoming a promising choice for self-sustainable communication systems as an external power supply or a dedicated carrier emitter is not required. By leveraging existing RF signal resources, ambient backscatter technology can support sustainable and independent communications and consequently open up ...

ERS-1 SAR imagery of lake ice growing on shallow lundra lakes in northern Alaska shows interesting radar backscatter variations. Based on the analysis of ice cores from these lakes, a multi-layer backscatter model comprised of the following elements has been developed: I) specular air-ice, ice-water and ice-frown soil boundaries; 2) an ice layer of variable thickness; 3) ice sub-layers with air...