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This paper introduces a contribution made to one of the newest methods for simulating indirect lighting in dynamic scenes , the cascaded light propagation volumes . Our contribution consists on using Spherical Radial Basis Functions instead…

Computer Vision and Pattern Recognition · Computer Science 2024-07-25 Ludovic Silvestre , João Pereira

Spectral retrieval techniques are currently our best tool to interpret the observed exoplanet atmospheric data. Said techniques retrieve the optimal atmospheric components and parameters by identifying the best fit to an observed…

Earth and Planetary Astrophysics · Physics 2020-10-21 Kai Hou Yip , Ingo P. Waldmann , Angelos Tsiaras , Giovanna Tinetti

Speckle noise severely limits the quality of images acquired from coherent imaging systems such as Synthetic Aperture Radar (SAR) and medical ultrasound. Traditional second-order PDE-based despeckling approaches, although popular, often…

Image and Video Processing · Electrical Eng. & Systems 2026-05-05 Manish Kumar , Rajendra K. Ray

In many applications data are measured or defined on a spherical manifold; spherical harmonic transforms are then required to access the frequency content of the data. We derive algorithms to perform forward and inverse spin spherical…

Astrophysics · Physics 2011-10-28 J. D. McEwen

We present results of numerical simulations of the flux (irradiance), F, and the degree of polarization (i.e. the ratio of polarized to total flux), P, of light that is reflected by Earth-like extrasolar planets orbiting solar-type stars,…

Astrophysics · Physics 2009-11-13 D. M. Stam

We investigate integral formulations and fast algorithms for the steady-state radiative transfer equation with isotropic and anisotropic scattering. When the scattering term is a smooth convolution on the unit sphere, a model reduction step…

Numerical Analysis · Mathematics 2019-02-20 Yuwei Fan , Jing An , Lexing Ying

The Radiative transfer coherent backscattering (RT-CB) code is extended to apply to dense discrete random media of optically soft spherical particles. This is achieved by utilizing the well-known static-structure-factor (SSF) correction…

Materials Science · Physics 2023-11-23 Johannes Markkanen , Antti Penttilä

At optical wavelengths, an exoplanet's signature is essentially reflected light from the host star - several orders of magnitude fainter. Since it is superimposed on the star spectrum its detection has been a difficult observational…

Earth and Planetary Astrophysics · Physics 2013-10-07 Jorge H. C. Martins , Pedro Figueira , Nuno Santos , Christophe Lovis

We present new methodological features and physical ingredients included in the 1D radiative transfer code HELIOS, improving the hemispheric two-stream formalism. We conduct a thorough intercomparison survey with several established forward…

Rendering highly scattering participating media using brute force path tracing is a challenge. The diffusion approximation reduces the problem to solving a simple linear partial differential equation. Flux-limited diffusion introduces…

Graphics · Computer Science 2018-07-03 David Koerner , Jamie Portsmouth , Wenzel Jakob

Computational spectrometers are pivotal in enabling low-cost, in-situ and rapid spectral analysis, with potential applications in chemistry, biology, and environmental science. However, filter-based spectral encoding approaches typically…

Future space-based direct imaging missions will perform low-resolution (R$<$100) optical (0.3-1~$\mu$m) spectroscopy of planets, thus enabling reflected spectroscopy of cool giants. Reflected light spectroscopy is encoded with rich…

Earth and Planetary Astrophysics · Physics 2021-04-14 Sagnick Mukherjee , Natasha E. Batalha , Mark S. Marley

We present the open-source radiative transfer code named HELIOS, which is constructed for studying exoplanetary atmospheres. In its initial version, the model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of…

3D image processing constitutes nowadays a challenging topic in many scientific fields such as medicine, computational physics and informatics. Therefore, development of suitable tools that guaranty a best treatment is a necessity.…

Numerical Analysis · Computer Science 2018-05-22 Malika Jallouli , Wafa Bel Hadj Khalifa , Anouar Ben Mabrouk , Mohamed Ali Mahjoub

We present a new radiative transfer method (SPH-M1RT) that is coupled dynamically with smoothed particle hydrodynamics (SPH). We implement it in the (task-based parallel) SWIFT galaxy simulation code but it can be straightforwardly…

Instrumentation and Methods for Astrophysics · Physics 2021-07-06 T. K. Chan , Tom Theuns , Richard Bower , Carlos Frenk

Studying the albedos of the planets and moons of the Solar System dates back at least a century. Of particular interest is the relationship between the albedo measured at superior conjunction, known as the ``geometric albedo", and the…

Earth and Planetary Astrophysics · Physics 2021-08-30 Kevin Heng , Brett M. Morris , Daniel Kitzmann

Our ability to observe, detect, and characterize exoplanetary atmospheres has grown by leaps and bounds over the last 20 years, aided largely by developments in astronomical instrumentation; improvements in data analysis techniques; and an…

Earth and Planetary Astrophysics · Physics 2025-09-17 Nikolai Piskunov , Adam D. Rains , Linn Boldt-Christmas

Polarimetry is about to become a powerful tool for determining the atmospheric properties of exoplanets. To provide the basis for the interpretation of observational results and for predictive studies to guide future observations,…

Earth and Planetary Astrophysics · Physics 2021-02-03 Moritz Lietzow , Sebastian Wolf , Robert Brunngräber

The characterization of exoplanet atmospheres is one of the key topics in modern astrophysics. To date, transmission spectroscopy has been the primary method used, but upcoming instruments will lay the foundation for advancing…

Earth and Planetary Astrophysics · Physics 2025-09-10 Maddalena Bugatti , Christophe Lovis , Nicolas Billot , Nicolas Blind , Baptiste Lavie , Martin Turbet , Bruno Chazelas , Francesco Pepe

We present new functionality within PICASO, a state-of-the-art radiative transfer model for exoplanet and brown dwarf atmospheres, by developing a new pipeline that computes phase-resolved thermal emission (thermal phase curves) from…

Earth and Planetary Astrophysics · Physics 2022-05-18 Nina Robbins-Blanch , Tiffany Kataria , Natasha E. Batalha , Danica J. Adams