Gilerson, Alexander: CUNY (Project Lead)
Project Funding:
2016 - 2020
NRA: 2015 NASA: Ocean Biology and Biogeochemistry
Funded by NASA
Abstract:
Remote sensing (RS) measurements which include the polarimetric characteristics of light provide more intrinsic information about micro and macro- physical properties of
aerosols/hydrosols than standard RS measurements. It is planned that future NASA satellite PACE mission will have a polarimeter on board. Under current NASA funding using vector radiative transfer (VRT) simulations for a coupled ocean-atmosphere system and various measurements advantages of the polarimetric observations were successfully demonstrated for the retrieval of the ratio of attenuation-to-absorption coefficients (c/a) in water, coefficients themselves as well as some microphysical properties of hydrosols. During NASA SABOR cruise in water measurements were combined with above water continuous underway observations by the HyperSAS-POL instrument on the ship and with airborne measurements of the NASA GISS
Research Scanning Polarimeter. To resolve an issue of a glint (sky + Sun) correction for the upwelling polarized signal from a wind driven ocean surface and various atmospheres and observation conditions Monte Carlo and VRT simulations were employed to develop related reflectance and transmittance matrices.
Collected polarimeteric reflectance data above and below water in the SABOR cruise and more recently in NOAA VIIRS validation cruises 2014-2015 together with in situ and flow through measurements and bio-chemical data open a strong potential for further establishment of relationships between polarimetric observations above water with microphysical characteristics of ocean particulates. Thus accurate matchups between measured polarization characteristics and properties of in-water particulates strongly depend on the in-water scattering matrices. Full matrices were not measured directly in any of the cruises mentioned above but can be constructed with some assumptions based on the set of measured microphysical parameters of particulates which should lead to the establishment of the additional connections between the degree of polarization and particle characteristics. Using sensitivity studies through VRT simulations and matchups between in situ and RSP data possible expansion of these relationships to the TOA level will be evaluated. Combined VRT and Monte Carlo based approach for polarized sky-sun glint correction for a wind driven ocean surface with variable aerosol loadings will be fully developed for improved estimation of polarized remote sensing reflectance in above water measurements for various atmospheric and observational conditions.
Additional data will be collected during cruises of opportunity and from the Long Island Sound Coastal Observatory (LISCO) platform for the validation of the developed models. Data collected during current as well as proposed project will be used to develop unique polarimetric hyperspectral datasets for various water, atmospheric and observation conditions. The proposed datasets are critical for the evaluation of the advantages of the polarimetric observations in PACE and other OC missions, development of the advanced algorithms for the retrieval of characteristics of water particulates and atmospheric correction models.
More details may be found in the following project profile(s):
