Realistic uncertainties on Hapke model parameters from photometric measurement

Schmidt, Frédéric; Fernando, J.

doi:10.1016/j.icarus.2015.07.002

Cited by 44 publications

(44 citation statements)

References 38 publications

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“…To quantify the evolution of the photometric behavior of each sample with the wavelength, we used the procedure developed by Fernando et al (2013Fernando et al ( , 2015 using the fast implementation strategy of Schmidt and Fernando (2015). This methodology uses a Bayesian approach to estimate photometric parameters from the Hapke model (Hapke, 1993).…”

Section: Inversion Methodsmentioning

confidence: 99%

“…The prior information about model parameters (no information is defined as uniform PDF) combined with prior information about observations (a Gaussian PDF) are fused to infer the solution by using Bayes theory. The final state of information (posterior PDF of each parameter) is numerically sampled, using a Monte Carlo Markov Chain (Mosegaard and Tarantola, 1995) with an adaptative Metropolis method (Schmidt and Fernando, 2015), to calculate the posterior PDF.…”

Section: Inversion Methodsmentioning

confidence: 99%

“…The incidence angle was set to an intermediate value of 45°and the bidirectional reflectance was measured in the principal plane at various emergence angles from À70°to +70°. Such measurements in the illumination plane with phase angles ranging from 15°to 115°are indeed sufficient to characterize the scattering behaviors of the samples and their potential variations using the Hapke model (Schmidt and Fernando, 2015) (except for the opposition effect, which would require phase angles lower than 15°). A Labsphere Ò Spectralon sample was used as a reference target.…”

Section: Data Acquisitionmentioning

confidence: 99%

See 2 more Smart Citations

Wavelength dependence of scattering properties in the VIS–NIR and links with grain-scale physical and compositional properties

Pilorget

Fernando

Ehlmann

et al. 2016

Icarus

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Section: Inversion Methodsmentioning

confidence: 99%

Section: Inversion Methodsmentioning

confidence: 99%

Section: Data Acquisitionmentioning

confidence: 99%

See 1 more Smart Citation

Wavelength dependence of scattering properties in the VIS–NIR and links with grain-scale physical and compositional properties

Pilorget

Fernando

Ehlmann

et al. 2016

Icarus

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“…[17][18][19][20][21][22][23][24][25][26] The isotropic multiple scattering approximation (IMSA) is an approximate solution to an RTE based on the Chandresekhar-Ambartsumian method of invariance. 4 In the Hapke treatment of the RTE, five orders of scattering are considered, and the single scattering contribution through the single scattering phase function is treated in an exact form; however, for multiple scattering contributions, the phase function is assumed to be isotropic.…”

Section: Radiative Transfer Models For Retrieval Of Sediment Geophysimentioning

confidence: 99%

Modeling and intercomparison of field and laboratory hyperspectral goniometer measurements with G-LiHT imagery of the Algodones Dunes

Bachmann

Eon

Ambeau

et al. 2017

J. Appl. Remote Sens

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Abstract. We compare field hyperspectral bidirectional reflectance distribution function (BRDF) measurements acquired by a hyperspectral goniometer system known as the goniometer of the Rochester Institute of Technology (GRIT) during an experiment in the Algodones Dunes system in March 2015 with NASA Goddard's light detection and ranging, hyperspectral, and thermal imagery of the site acquired during the experiment. We augment our field spectral data collection with laboratory hyperspectral BRDF measurements of samples brought back from the Algodones Dunes site using GRIT and our second-generation goniometer GRIT-two (GRIT-T).In these laboratory experiments, we vary geophysical parameters such as sediment density and grain size distribution of the sediments that would typically impact observed BRDF with the goal of extending the range of applicability of our resulting BRDF spectral libraries. Geotechnical measurements on site confirm the variability of geophysical parameters such as density and grain size distributions within the dune system, and measurements with GRIT and GRIT-T demonstrate the impact on observed spectral variation. By augmenting field spectral libraries with laboratory BRDF, we show that a greater proportion of the dune system is more faithfully represented in the expanded spectral library. Beyond developing appropriate calibration data for airborne and satellite imagery of the Algodones Dunes, laboratory and field studies also support goals to develop reliable retrieval methods for geophysical quantities such as sediment density directly from spectral imagery. We consider approaches based on the Hapke model. Our approaches use the invariance of the observed functional forms of the single scattering phase function, which must be invariant to differences in the illumination geometry. Fill factor is retrieved and correlates with expected direct measurements of sediment density in a laboratory setting. © The Authors.Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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“…In the case of the Hapke model, the entangling of its parameters, mainly the w, g sca andθ , have been widely criticized for a few decades (Helfenstein and Veverka, 1989). Nevertheless Fernando et al (2013), Fernando et al (2015a) and Schmidt and Fernando (2015) have recently applied a Bayesian inversion to study the probabilistic density function of each Hapke parameter and their degeneracy. Their study has found that w, b, c andθ follow a unimodal distribution around the solution and the parameters can be described with a mean and standard deviation when uncertainties are lower than about 5%.…”

Section: H(x W)mentioning

confidence: 99%

Asteroid (21) Lutetia: Disk-resolved photometric analysis of Baetica region

Hasselmann

Fornasier

Leyrat

et al. 2016

Icarus

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ABSTRACT. (21) Lutetia has been visited by Rosetta mission on July 2010 and observed with a phase angle ranging from 0.15 to 156.8 degrees. The Baetica region, located at the north pole has been extensively observed by OSIRIS cameras system. Baetica encompass a region called North Pole Crater Cluster (NPCC), shows a cluster of superposed craters which presents signs of variegation at the small phase angle images. For studying the location, we used 187 images distributed throughout 14 filter recorded by the NAC (Narrow Angle Camera) and WAC (Wide Angle Camera) of the OSIRIS system on-board Rosetta taken during the fly-by. Then, we photometrically modeled the region using Minnaert diskfunction and Akimov phase function to obtain a resolved spectral slope map at phase angles of 5 • and 20 • . We observed a dicothomy between Gallicum and Danuvius-Sarnus Labes in the NPCC, but no significant phase reddening (−0.04 ± 0.045% · microns −1 deg −1 ). In the next step, we applied the Hapke (2008Hapke ( ,2012 model for the NAC F82+F22 (649.2 nm), WAC F13 (375 nm) and WAC F17 (631.6 nm) and we obtained normal albedo maps and Hapke parameter maps for NAC F82+F22. On Baetica, at 649.2 nm, the geometric albedo is 0.205 ± 0.005, the average single-scattering albedo is 0.181 ± 0.005, the average asymmetric factor is −0.342 ± 0.003, the average shadow-hiding opposition effect amplitude and width are 0.824 ± 0.002 and 0.040 ± 0.0007, the average roughness slope is 11.45 • ± 3 • and the average porosity is 0.85 ± 0.002. We are unable to confirm the presence of coherent-backscattering mechanism. In the NPCC, the normal albedo variegation among the craters walls reach 8% brighter for Gallicum Labes and 2% fainter for Danuvius Labes. The Hapke parameter maps also show a dicothomy at the opposition effect coefficients, single-scattering albedo and asymmetric factor, that may be attributed to the maturation degree of the regolith or to compositonal variation. In addition, we compared the Hapke (2008Hapke ( , 2012 and Hapke (1993) parameters with laboratory samples and other small-solar system bodies visited by space missions.

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Realistic uncertainties on Hapke model parameters from photometric measurement

Cited by 44 publications

References 38 publications

Wavelength dependence of scattering properties in the VIS–NIR and links with grain-scale physical and compositional properties

Wavelength dependence of scattering properties in the VIS–NIR and links with grain-scale physical and compositional properties

Modeling and intercomparison of field and laboratory hyperspectral goniometer measurements with G-LiHT imagery of the Algodones Dunes

Asteroid (21) Lutetia: Disk-resolved photometric analysis of Baetica region

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