scholarly journals Mie scattering and the Martian atmosphere

1971 ◽  
Vol 40 ◽  
pp. 156-165
Author(s):  
Walter G. Egan ◽  
Kenneth M. Foreman
Keyword(s):  
Radio Occultation ◽  
Martian Atmosphere ◽  
Mie Scattering ◽  
Index Of Refraction ◽  
Viewing Angle ◽  
Angle Dependence ◽  
Bulk Solid ◽  
Visual Range ◽  
Complex Index Of Refraction

It has been suggested that the discrepancy between radio occultation determinations of the Martian atmospheric surface pressure (3.8 to 7 mb) and those deduced from optical polarization measurements and a simple Rayleigh atmosphere model (about 10 mb) are the results of sub-micron sized aerosols in the Martian atmosphere. Based on observed viewing angle dependence of the polarization of the Martian disk in the visual range, a Mie scattering analysis has been made utilizing the measured complex index of refraction of limonite and bulk solid CO2. The results of this study indicate that limonite aerosols alone are unsatisfactory to explain the viewing angle observations, whereas solid CO2 (and H2O ice) aerosol spheres, having a dominant particle radius range between 0.28 and 0.35 μ, could bring planetary and laboratory observations into compatibility. It is suggested, further, that solid CO2 aerosols could explain limb brightening in the blue spectral range. Various distributions of solid CO2 and H2O Mie particles with radii up to 0.35 μ show an opposition effect. However, the role of these aerosols in explaining the Mars opposition observations is very dependent on the optical properties of the underlying Mars surface material.

Mie Scattering with Complex Index of Refraction

1961 ◽  
Vol 51 (6) ◽  
pp. 620 ◽  
Author(s):  
D. Deirmendjian ◽  
R. Clasen ◽  
W. Viezee
Keyword(s):  
Mie Scattering ◽  
Index Of Refraction ◽  
Complex Index ◽  
Complex Index Of Refraction

scholarly journals Graphite and Interstellar Extinction

1965 ◽  
Vol 7 ◽  
pp. 5-10
Author(s):  
T. P. Stecher ◽  
Bertram Donn
Keyword(s):  
Cross Section ◽  
Optical Constants ◽  
Preceding Paper ◽  
Interstellar Extinction ◽  
Mie Scattering ◽  
Index Of Refraction ◽  
Spherical Particles ◽  
Complex Dielectric Constant ◽  
Integrated Cross Section ◽  
Complex Index Of Refraction

The Theory That Graphite Particles could be responsible for interstellar extinction is presented in references 1 and 2, and this paper will present evidence that further supports this contention. The complex dielectric constant (m = n(l — ik) for graphite has been measured as a function of energy by the authors of reference 3, and the optical constants as function of wavelength λ have been obtained from this measurement. A large variation occurs in both n and k at wavelengths below 3000 Å.The results reported in the preceding paper indicated the desirability of performing Mie scattering calculations on graphite. The measured values of the complex index of refraction corresponding to 17 wavelengths were used in the calculation for spherical particles. The IBM 7094 computer program for Mie scattering follows that of van de Hulst. (See ref. 4.) The Oort-van de Hulst size distribution (ref. 5), which may not be applicable to the type of particle discussed herein, has been used to obtain an integrated cross section for extinction.

scholarly journals Progress in turbulence detection via GNSS occultation data

2012 ◽  
Vol 5 (4) ◽  
pp. 789-808 ◽  
Author(s):  
L. B. Cornman ◽  
R. K. Goodrich ◽  
P. Axelrad ◽  
E. Barlow
Keyword(s):  
Power Spectrum ◽  
Radio Occultation ◽  
Real Data ◽  
Index Of Refraction ◽  
Estimation Methods ◽  
Model Parameters ◽  
Phase Fluctuations ◽  
Global Statistics ◽  
Occultation Data ◽  
Parameter Estimators

Abstract. The increased availability of radio occultation (RO) data offers the ability to detect and study turbulence in the Earth's atmosphere. An analysis of how RO data can be used to determine the strength and location of turbulent regions is presented. This includes the derivation of a model for the power spectrum of the log-amplitude and phase fluctuations of the permittivity (or index of refraction) field. The bulk of the paper is then concerned with the estimation of the model parameters. Parameter estimators are introduced and some of their statistical properties are studied. These estimators are then applied to simulated log-amplitude RO signals. This includes the analysis of global statistics derived from a large number of realizations, as well as case studies that illustrate various specific aspects of the problem. Improvements to the basic estimation methods are discussed, and their beneficial properties are illustrated. The estimation techniques are then applied to real occultation data. Only two cases are presented, but they illustrate some of the salient features inherent in real data.

Optical properties of amorphous hydrogenated carbon films: A spectroscopic ellipsometry study

1987 ◽  
Vol 2 (5) ◽  
pp. 645-647 ◽  
Author(s):  
Shuhan Lin ◽  
Shuguang Chen
Keyword(s):  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Carbon Films ◽  
Index Of Refraction ◽  
The Real ◽  
Complex Index ◽  
Tentative Explanation ◽  
Amorphous Hydrogenated Carbon ◽  
Ellipsometry Data ◽  
Complex Index Of Refraction

Optical properties of plasma-deposited amorphous hydrogenated carbon films were studied by spectroscopic ellipsometry. From the ellipsometry data, the real and imaginary parts, n and k, of the complex index of refraction of the film have been deduced for photon energies between 2.0 and 4.0 eV for as-grown as well as for thermally annealed films. Here n and k showed considerable variation with subsequent annealing, even under 400°C. A tentative explanation of the results is proposed.

scholarly journals Role of Mie scattering in the seeding of matter-wave superradiance

2012 ◽  
Vol 86 (4) ◽  
Author(s):  
R. Bachelard ◽  
H. Bender ◽  
Ph. W. Courteille ◽  
N. Piovella ◽  
C. Stehle ◽  
...  
Keyword(s):  
Mie Scattering ◽  
Matter Wave
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