The most important factor affecting the microwave proper-ties of a snowcover is the liquid water content (snow wetness). An FM-CW(26.5-40 GHz) radar has been used to investigate the influence of snowwetness on the magnitude of radar backscatter from a snowcover. Theradar backscatter measurements from a wet snowcover on a windy daysuggest that evaporative cooling due to the w...

Backscatter differential phase is one of the polarimetric variables which can be estimated from the measurements by dualpolarization weather radars. By definition, the backscatter differential phase δ is a difference between the phases of horizontally and vertically polarized components of the backscattered wave upon reflection from the scatterers within the radar resolution volume. It contribu...

Dose per monitor unit in photon fields generated by clinical linear accelerators can be affected by the backscattered radiation into the monitor chamber from collimator jaws. Thus, it is necessary to account for the backscattered radiation in computing monitor unit setting for a treatment field. In this work, we investigated effects of the backscatter from collimator jaws based on Monte Carlo s...

Mapping of natural and man-made water bodies is a critical component of environmental studies, including climate change, agriculture, flood forecasting and groundwater recharge estimation. Moreover, standing water heavily impacts the ability to accurately estimate soil moisture from satellite, particularly from low resolution passive microwave data using a radiometer. NASA’s soil moisture dedic...

NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et a...

Understanding the relationship between fish biology and target strength potentially improves the accuracy of acoustic assessments. The effects of individual biological factors (e.g., length, tilt, and depth) on backscatter amplitude have been examined, but the relative contribution of each factor has not been quantified. Dimensionless ratios, which facilitate comparison of disparate quantities,...

In a previous paper this author demonstrated how a macroecological plant model could be used to parameterize a backscatter model with the aim of predicting trends in backscatter and height as a function of vegetation biomass. The macroecological model used is of interest because it gives a simple description of the plant structure but remains within realistic biophysical limits. The aim of this...

A new multi-antenna or multiple-input-multiple-output (MIMO) configuration is introduced for RF modulated backscatter in a multipath environment. RF modulated backscatter is used by semipassive RF tags to transmit without a power amplifier, and is therefore appropriate for applications with extreme power constraints such as sensor communications, electronic shelf tags, electronic toll collectio...

We present high-precision measurements of pure element stable isotope pairs that demonstrate mass has no influence on the backscattering of electrons at typical electron microprobe energies. The traditional prediction of average backscatter intensities in compounds was pragmatically based on elemental mass fractions. Our isotopic measurements establish that this approximation has no physical ba...