Publication Abstracts
Ibrahim et al. 2016
Ibrahim, A., A. Gilerson,
, and S. Ahmed, 2016: Retrieval of macro- and micro-physical properties of oceanic hydrosols from polarimetric observations. Remote Sens. Environ., 186, 548-566, doi:10.1016/j.rse.2016.09.004.Remote sensing has mainly relied on measurements of scalar radiance and its spectral and angular features to retrieve micro- and macro-physical properties of aerosols/hydrosols. However, it is recognized that measurements that include the polarimetric characteristics of light provide more intrinsic information about particulate scattering. To take advantage of this, we used vector radiative transfer (VRT) simulations and developed an analytical relationship to retrieve the macro and micro-physical properties of the oceanic hydrosols. Specifically, we investigated the relationship between the observed degree of linear polarization (DoLP) and the ratio of attenuation-to-absorption coefficients (c/a) in water, from which the scattering coefficient can be readily computed (b = c s - a), after retrieving a. This relationship was parameterized for various scattering geometries, including sensor zenith/azimuth angles relative to the Sun's principal plane, and for varying Sun zenith angles. An inversion method was also developed for the retrieval of the microphysical properties of hydrosols, such as the bulk refractive index and the particle size distribution. The DoLP vs c/a relationship was tested and validated against in-situ measurements of underwater light polarization obtained by a custom-built polarimeter and measurements of the coefficients a and c, obtained using an in-water WET Labs ac-s instrument package. These measurements confirmed the validity of the approach, with retrievals of attenuation coefficients showing a high coefficient of determination depending on the wavelength. We also performed a sensitivity analysis of the DoLP at the Top of Atmosphere (TOA) over coastal waters showing the possibility of polarimetric remote sensing application for ocean color.
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BibTeX Citation
@article{ib02000c, author={Ibrahim, A. and Gilerson, A. and Chowdhary, J. and Ahmed, S.}, title={Retrieval of macro- and micro-physical properties of oceanic hydrosols from polarimetric observations}, year={2016}, journal={Remote Sens. Environ.}, volume={186}, pages={548--566}, doi={10.1016/j.rse.2016.09.004}, }
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RIS Citation
TY - JOUR ID - ib02000c AU - Ibrahim, A. AU - Gilerson, A. AU - Chowdhary, J. AU - Ahmed, S. PY - 2016 TI - Retrieval of macro- and micro-physical properties of oceanic hydrosols from polarimetric observations JA - Remote Sens. Environ. VL - 186 SP - 548 EP - 566 DO - 10.1016/j.rse.2016.09.004 ER -
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