Abstract

Total and polarized radiances from above the ocean surface are measured by a state-of-the-art snapshot hyperspectral imager. A computer-controlled filter wheel is installed in front of the imager allowing for recording of division-of-time Stokes vector images from the ocean surface. This system, to the best of our knowledge, for the first time provided a capability of hyperspectral polarimetric multi-angular measurements of radiances from above the water surface. Several sets of measurements used in the analysis were acquired from ocean platforms and from shipborne observations. Measurements made by the imager are compared with simulations using a vector radiative transfer (VRT) code showing reasonable agreement. Analysis of pixel-to-pixel variability of the total and polarized above-water radiance for the viewing angles of 20°–60° in different wind conditions enable the estimation of uncertainties in measurements of these radiances in the polarized mode for the spectral range of 450–750 nm, thus setting requirements for the quality of polarized measurements. It is shown that there is a noticeable increase of above-water degree of linear polarization (DoLP) as a function of the viewing angle, which is due both to the larger DoLP of the light from the water body and the light reflected from the ocean surface. Results of measurements and VRT simulations are applied for the multi-angular retrieval of the ratio of beam attenuation coefficient (${c_\textrm{tot}}$) to absorption coefficient (${a_\textrm{tot}}$) in addition to the other parameters such as absorption and backscattering coefficients retrieved from traditional unpolarized methods.

© 2020 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Characterization of radiance from the ocean surface by hyperspectral imaging

Carlos Carrizo, Alexander Gilerson, Robert Foster, Andrii Golovin, and Ahmed El-Habashi
Opt. Express 27(2) 1750-1768 (2019)

Retrieval of aerosol properties and water-leaving reflectance from multi-angular polarimetric measurements over coastal waters

Meng Gao, Peng-Wang Zhai, Bryan Franz, Yongxiang Hu, Kirk Knobelspiesse, P. Jeremy Werdell, Amir Ibrahim, Feng Xu, and Brian Cairns
Opt. Express 26(7) 8968-8989 (2018)

Variability of the reflectance coefficient of skylight from the ocean surface and its implications to ocean color

Alexander Gilerson, Carlos Carrizo, Robert Foster, and Tristan Harmel
Opt. Express 26(8) 9615-9633 (2018)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (12)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (2)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (5)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription