Deriving anisotropic correction for upwelling radiance from PACE's multi-angle polarimetry
Document Type
Article
Publication Date
4-1-2025
Department
Marine Science
School
Ocean Science and Engineering
Abstract
NASA's Plankton, Aerosol, Clouds, ocean Ecosystem (PACE) mission, launched on 8th February 2024, carries a hyperspectral radiometer, Ocean Color Instrument (OCI) and two multi-angle polarimeters, Hyper Angular Rainbow Polarimeter (HARP2) and Spectro-Polarimeter for Planetary Exploration one (SPEX-one). The simultaneous deployment of these sensors offers an unprecedented opportunity to derive more accurate bidirectional factors for correcting the Sun-sensor viewing dependence of the remote sensing reflectance derived from OCI. With a bidirectional remote sensing model based on quasi-single-scattering approximation to the radiative transfer equation, the angular shape of the volume scattering function (VSF) in backward directions, i.e., the χ factor for particles (χp) is derived from the multi-angle observation of HARP2. The derived χp is in turn used to drive the bidirectional remote sensing model to predict the bidirectional factor. Testing with prelaunch simulated HARP2 L1C data that includes uncertainties due to atmospheric correction, the proposed method can estimate bidirectional factor with an uncertainty <10 % at any three visible bands of HARP2. Because the proposed method estimates the χp directly from the multi-angle observation, it fully accounts for the natural variability of VSFs, which were assumed to confine within a limited range of variation in the earlier bidirectional correction models.
Publication Title
Remote Sensing of Environment
Volume
320
Recommended Citation
Zhang, X.,
Gao, M.,
He, S.,
Barbedo, L.
(2025). Deriving anisotropic correction for upwelling radiance from PACE's multi-angle polarimetry. Remote Sensing of Environment, 320.
Available at: https://aquila.usm.edu/fac_pubs/21908
COinS