Foam on the ocean surface significantly increases the brightness temperatures measured by microwave radiometers. Previous results have shown that the microwave emissivity of foam on a calm water surface is significantly less than one and depends upon polarization and incidence angle. Recent radiometric and video observations of large-scale breaking waves from the R/P FLIP during the FAIRS exper...

The multiband MBP 98A pyrometer developed for non-contact temperature measurement of objects with unknown and wavelength-dependent emissivity has been presented in this paper. The pyrometer was designed using single thermoelectrically cooled PbS detector of spectral band of 1-2.5 Ilm and 8 narrow-band optical filters. It enables temperature measurement of objects at temperature within a range o...

We show that the direct Urca process of neutrino emission is allowed in two possible phases of nonspherical nuclei (inverse cylinders and inverse spheres) in the mantle of a neutron star near the crust-core interface. The process is open because neutrons and protons move in a periodic potential created by inhomogeneous nuclear structures. In this way the nucleons acquire large quasimomenta need...

Transition probabilities governing the interaction of energy packets and matter are derived that allow Monte Carlo NLTE transfer codes to be constructed without simplifying the treatment of line formation. These probabilities are such that the Monte Carlo calculation asymptotically recovers the local emissivity of a gas in statistical and radiative equilibrium. Numerical experiments with one-po...

We derive expressions for the total and linearly-polarized synchrotron emissivity of an element of plasma containing relativistic particles and disordered magnetic field which has been sheared or compressed along three independent directions. Our treatment follows that given by Matthews & Scheuer (1990) in the special case of a power-law electron energy spectrum. We show that the emissivity int...

The emission from the vegetation canopy depends on the type of vegetation and the frequencies at which the emission is measured. For studying the vegetation canopy of a tree, the dielectric constant of its constituent is measured at microwave frequencies. In this study the dielectric constant is measured using waveguide cell method and its scattering coefficient is estimated using perturbation ...

A high temperature oil-bath-based-black-body source has been designed and constructed in the Radiometric Physics Division at the National Institute of Standards and Technology, Gaithersburg, MD. The goal of this work was to design a large aperture blackbody source with highly uniform radiance across the aperture, good temporal stability, and good reproducibility. This blackbody source operates ...

A third generation water bath based black-body source has been designed and constructed in the Radiometric Physics Division at the National Institute of Standards and Technology, Gaithersburg, MD. The goal of this work was to design a large aperture blackbody source with improved temporal stability and reproducibility compared with earlier designs, as well as improved ease of use. These blackbo...