Applying a microfacet model to polarized light scattering measurements of the Earth's surface

Kupinski, Meredith; Bradley, Christine; Diner, David J.; Xu, Feng; Chipman, Russell A.

doi:10.1117/12.2188207

Cited by 5 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, if the illumination polarization is known, the extension of the analysis to this case is relatively straightforward. We note that the fourth Stokes component, corresponding to the circular polarization state, is not measured by the Ground-MSPI due to its insignificant contribution in most natural scenes [1][2]4,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

Section: Model Developmentmentioning

confidence: 97%

“…For clear sky conditions, the direct illumination generally dominates unless the Sun is low in the sky. Thus, in this work, as well as other passive remote sensing studies [1,[15][16][17][18][19][20][21][22], the scene illumination is considered to be unpolarized. This assumption may not be accurate for certain conditions such as a partly cloudy sky or for relatively smooth surfaces that produce significant specular reflections of the partially polarized sky irradiance.…”

Section: Model Developmentmentioning

confidence: 99%

“…We assume the diffuse scattering is completely unpolarized and Lambertian where the light encounters enough multiple scattering events within the bulk of the material that the scattering directions and polarization state are uniformly random. In general, the diffuse scattering may exhibit some polarization and directional preference due to the re-emergence processes [23], but the assumptions of unpolarized and Lambertian scattering are reasonable especially for remote sensing scenarios where the target's surface roughness is typically large compared to the incident wavelength [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. In contrast, the surface scattering that develops based on a microfacet model, can produce a directional lobe and polarization preference.…”

Section: Model Developmentmentioning

confidence: 99%

“…describes the depolarization phenomena of the diffuse scattering, which is defined with no polarization preference in this case [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. A convenient reflectance parameter ρ d , based on Kubelka-Munk (KM) theory [27] and the work by Le Hors et al [26], has been developed to describe the intensity ratio of the diffuse scattering to the scattering from a perfect Lambertian surface.…”

Section: Model Developmentmentioning

confidence: 99%

“…To our knowledge, this is the first time that images of surface parameters have been generated from polarimetric field data. The polarimetric data for this work was collected with the Ground Multiangle SpectroPolarimetric Imager (Ground-MSPI) [15][16], which is a camera system developed to provide Stokes parameter images at narrowband wavelengths of 470 nm, 660 nm and 865 nm [17][18][19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Parameter-based imaging from passive multispectral polarimetric measurements

2019

Self Cite

View full text Add to dashboard Cite

A modified pBRDF model with a diffuse scattering component is applied to estimate the complex refractive index, slope variance roughness, and diffuse scattering coefficients of object surfaces from time sequences of polarimetric images. The approach is used for the first time to produce parameter-based images from multispectral Stokes imagery of outdoor target scenes collected by the Ground Multiangle Spectro-Polarimetric Imager. The images of the estimated surface parameters show distinctions between different objects in the scenes and the parameter values are consistent with reasonable expectations for the object surfaces.

show abstract

Section: Model Developmentmentioning

confidence: 97%

Section: Model Developmentmentioning

confidence: 99%

Section: Model Developmentmentioning

confidence: 99%

Section: Model Developmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Parameter-based imaging from passive multispectral polarimetric measurements

2019

Self Cite

View full text Add to dashboard Cite

show abstract

Estimating surface orientation from microfacet Mueller matrix bidirectional reflectance distribution function models in outdoor passive imaging polarimetry

et al. 2019

Self Cite

View full text Add to dashboard Cite

Representative examples from 3 years of measurements from JPL's ground-based multiangle spectropolarimetric imager (GroundMSPI) are compared to a Mueller matrix bidirectional reflectance distribution function (mmBRDF). This mmBRDF is used to model polarized light scattering from solar illuminated surfaces. The camera uses a photoelastic-modulator-based polarimetric imaging technique to measure linear Stokes parameters in three wavebands (470, 660, and 865 nm) with a AE0.005 uncertainty in degree of linear polarization. GroundMSPI measurements are made over a range of scattering angles determined from a fixed viewing geometry and varying sun positions over time. This microfacet mmBRDF model predicts an angle of the linear polarization that is consistently perpendicular to the scattering plane and therefore is only appropriate for rough surface types. The model is comprised of a volumetric reflection term plus a specular reflection term of Fresnel-reflecting microfacets. The following modifications to this mmBRDF model are evaluated: an apodizing shadowing function, a Bréon or Gaussian microfacet scattering density function, and treating the surface orientation as an additional model parameter in the specular reflection term. The root-mean-square error (RMSE) between the GroundMSPI measurements and these various forms of the microfacet mmBRDF model is reported. Four example scenes for which a shadowed-Bréon microfacet mmBRDF model yields realistic estimates of surface orientation, and the lowest RMSE among other model options are shown.

show abstract

Angle of linear polarization images of outdoor scenes

et al. 2019

Self Cite

View full text Add to dashboard Cite

Observations from the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) are used to relate angle of linear polarization (AoLP) measurements to material properties and illumination conditions in sunlit outdoor environments. GroundMSPI is a push-broom spectropolarimetric camera with an uncertainty in degree of linear polarization (DoLP) of AE0.005. This polarimetric accuracy yields useful AoLP images even when the DoLP is less than 0.02. AoLP images are reported with respect to dependency on surface texture, surface orientation, albedo, and illumination conditions. Agreement with well-known principles of polarized light scattering is illustrated, and several special cases are described. Expected observations of AoLP tangential to surface orientation and AoLP perpendicular to the scattering plane are reported. Significant changes in the AoLP are observed from common variations in outdoor illumination conditions. Also, simple variants in material properties change the dominant polarized light scattering process and thus the AoLP. Measurement examples that isolate a 90 deg AoLP flip are shown for a sunny and cloudy day as well as an object of high and low albedo. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Applying a microfacet model to polarized light scattering measurements of the Earth's surface

Cited by 5 publications

References 26 publications

Parameter-based imaging from passive multispectral polarimetric measurements

Parameter-based imaging from passive multispectral polarimetric measurements

Estimating surface orientation from microfacet Mueller matrix bidirectional reflectance distribution function models in outdoor passive imaging polarimetry

Angle of linear polarization images of outdoor scenes

Contact Info

Product

Resources

About