A new technique to find both real and imaginary index of refraction of atmospheric aerosols from clear sky radiance measurements.

Persistent Link:
http://hdl.handle.net/10150/187046
Title:
A new technique to find both real and imaginary index of refraction of atmospheric aerosols from clear sky radiance measurements.
Author:
Cooley, Thomas Wright.
Issue Date:
1995
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A new iterative technique to find both the real and imaginary index of refraction of atmospheric aerosols has been developed which utilizes polarized sky radiance measurements in the solar principal plane. The technique requires that the aerosol size distribution, Rayleigh optical depth, aerosol optical depth, surface albedo, and preferably the surface anisotropic characteristics be known from correlative measurements. The calculated optimal radiance ratio, which is the ratio of maximum sensitivity to the index being retrieved with minimum sensitivity to other parameters, is compared with the measured optimal radiance ratio. The retrieved index is found through iterative steps to minimize the difference between the measurement ratio and calculated ratio. The degree to which the uncertainties of the ensemble of parameters that affect retrieved index is assessed. Mie single scattering sensitivity simulations and radiative transfer simulations using a Gauss-Sidel routine are made to determine the sensitivity of polarized sky radiance to index, size distribution, surface albedo, and surface reflectance anisotropy. The results indicate that this inversion technique is viable, especially to retrieve the effective real index of refraction. While the retrieval of imaginary index did not work as consistently well as the retrieval of real index, the imaginary index retrieval yielded promising results with larger values of imaginary index (∼0.020). This technique also offers new insight into the effect surface anisotropy has on sky radiance.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Reagan, John A.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleA new technique to find both real and imaginary index of refraction of atmospheric aerosols from clear sky radiance measurements.en_US
dc.creatorCooley, Thomas Wright.en_US
dc.contributor.authorCooley, Thomas Wright.en_US
dc.date.issued1995en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA new iterative technique to find both the real and imaginary index of refraction of atmospheric aerosols has been developed which utilizes polarized sky radiance measurements in the solar principal plane. The technique requires that the aerosol size distribution, Rayleigh optical depth, aerosol optical depth, surface albedo, and preferably the surface anisotropic characteristics be known from correlative measurements. The calculated optimal radiance ratio, which is the ratio of maximum sensitivity to the index being retrieved with minimum sensitivity to other parameters, is compared with the measured optimal radiance ratio. The retrieved index is found through iterative steps to minimize the difference between the measurement ratio and calculated ratio. The degree to which the uncertainties of the ensemble of parameters that affect retrieved index is assessed. Mie single scattering sensitivity simulations and radiative transfer simulations using a Gauss-Sidel routine are made to determine the sensitivity of polarized sky radiance to index, size distribution, surface albedo, and surface reflectance anisotropy. The results indicate that this inversion technique is viable, especially to retrieve the effective real index of refraction. While the retrieval of imaginary index did not work as consistently well as the retrieval of real index, the imaginary index retrieval yielded promising results with larger values of imaginary index (∼0.020). This technique also offers new insight into the effect surface anisotropy has on sky radiance.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairReagan, John A.en_US
dc.contributor.committeememberHerman, Benjamin M.en_US
dc.contributor.committeememberThome, Kurtisen_US
dc.contributor.committeememberDvorak, Steven L.en_US
dc.identifier.proquest9531071en_US
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