The dependence of acoustic backscatter on sediment grain size distribution is examined using dual frequency (100 and 410 kHz) sidescan sonar and 22 sediment grab samples from the Loch Linnhe artificial reef site on the west coast of Scotland. The sidescan data were processed to remove an empirically estimated average grazing angle dependence on backscatter. The processed data were analysed by f...

Synthetic aperture radar (SAR) data were acquired over Bonanza Creek Experimental Forest (Alaska) in March 1988 under thawed and frozen conditions. For h e stands analyzed, Cband backscatter at 4 2 O 4 5 " lacidence angle was 2.7-6.9 dB smaller under frozen than under thawed conditions for white spruce and balsam poplar, with the largest difference at HV and the smallest at EM polarization. The...

The properties of PALSAR L-band backscatter and interferometric coherence of Siberian boreal forest are the topic of this paper. The cross-polarized backscatter (HV) is better suited than co-polarized backscatter (HH) for identification of forest cover changes, e.g. clear cuts and fire scars. Coherence acquired during winter also shows a good contrast between forested and nonforested areas. Our...

We examine the correspondence between high latitude ionospheric scintillation measurements made at 250 MHz with the occurrence of 10 MHz HF coherent radar backscatter, on 13 and 14 December 2002. We demonstrate that when the ionospheric intersection point of the scintillation measurements is co-located with significant HF radar backscatter, the observed scintillation, quantified by the S4 index...

Techniques for investigating acoustic backscatter from anisotropic biological tissues are examined. This empirical study combines single-scatter theory with the known elastic properties and histology of the renal cortex to predict the backscatter coefficient from kidney parenchyma. A transverse isotropic correlation model is developed to explain how backscattered energy, which varies with the i...

Recently, one of the authors (A. V. G.) developed a theory of low-frequency plasma irregularities which are created as a consequence of neutral turbulence in the D and lower E regions. In the following this theory will be applied to coherent backscatter experiments with radars in a frequency range between 5 and 150 MHz. We discuss the dependence of the backscatter cross-section on ionospheric a...

'Ihree upward looking acoustic Doppler current profilers (ADCP) were deployed beneath meteorological buoys in the Gulf of Tehuantepec. Mexico. during winter 1988-1989. Hourly averaged wind speed data from the buoys and from ship when in the vicinity were compared with surface acoustic backscatter intensity recorded at the ADCPs. The backscatter was found to be a significant predictor of wind sp...

In a previous experiment [Baddour et al., J. Acoust. Soc. Am. 117(2), 934-943 (2005)] it was shown that it is possible to deduce the ultrasound backscatter transfer function from single, subresolution cells in vitro, across a broad, continuous range of frequencies. Additional measurements have been performed at high frequencies (10-65 MHz) on cells with different relative nucleus sizes. It was ...

Whispering gallery delay lines have demonstrated record propagation length on a silicon chip and can provide a way to transfer certain applications of optical fiber to wafer-based systems. Their design and fabrication requires careful control of waveguide curvature and etching conditions to minimize connection losses between elements of the delay line. Moreover, loss characterization based on o...

Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazon's vast and remote humid tropical forests. Morning overpass QuikScat Ku-band microwave backscatter from the forest ...