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Related papers: Ray-Tracing studies in a perturbed atmosphere: I- …

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We describe a novel adaptive ray tracing scheme to solve the equation of radiative transfer around point sources in hydrodynamical simulations. The angular resolution adapts to the local hydrodynamical resolution and hence is of use for…

Astrophysics · Physics 2009-11-07 Tom Abel , Benjamin D. Wandelt

A measurement setup made of millimeter-wave and ultra wideband transceivers mounted on both a customized UAV and a ground station for full 3D wireless propagation analysis is described in this work. The developed system represents a…

Signal Processing · Electrical Eng. & Systems 2021-08-23 Franco Fuschini , Marina Barbiroli , Enrico M. Vitucci , Vasilii Semkin , Claude Oestges , Bruno Strano , Vittorio Degli-Esposti

This paper deals with simulation of flow and transport in porous media such as transport of groundwater contaminants. We first discuss how macro scale equations are derived and which terms have to be closed by models. The transport of…

Numerical Analysis · Mathematics 2018-07-03 Quanji Cai , Sheema Kooshapur , Michael Manhart , Ralf-Peter Mundani , Ernst Rank , Andreas Springer , Boris Vexler

We present initial attempts to include the multi-dimensional nature of radiation transport in hydrodynamical simulations of the small-scale structure that arises from the line-driven instability in hot-star winds. Compared to previous 1D or…

Astrophysics · Physics 2009-11-10 Luc Dessart , S. P. Owocki

We develop a field-theoretic framework, called radiant field theory, to calculate the distribution of transmission eigenvalues for coherent wave propagation in disordered media. At its core is a self-consistent transport equation for a…

Mathematical Physics · Physics 2025-07-21 David Gaspard , Arthur Goetschy

Differentiable ray tracing has recently challenged the status quo in radio propagation modelling and digital twinning. Promising unprecedented speed and the ability to learn from real-world data, it offers a real alternative to conventional…

Networking and Internet Architecture · Computer Science 2025-09-25 Stefanos Bakirtzis , Paul Almasan , José Suárez-Varela , Gabriel O. Ferreira , Michail Kalntis , André Felipe Zanella , Ian Wassell , Andra Lutu

We present a light and fast, public available, ray-tracer {\tt Splotch} software tool which supports the effective visualization of cosmological simulations data. We describe the algorithm it relies on, which is designed in order to deal…

Astrophysics · Physics 2008-12-18 K. Dolag , M. Reinecke , C. Gheller , S. Imboden

The atmospheres of planets (including Earth) and the outer layers of stars have often been treated in radiative transfer as plane-parallel media, instead of spherical shells, which can lead to inaccuracy, e.g. limb darkening. We give an…

Statistical Mechanics · Physics 2009-11-11 Michael J. Caola

Millimeter-wave (mmWave) communication is one of the cornerstone innovations of fifth-generation (5G) wireless networks, thanks to the massive bandwidth available in these frequency bands. To correctly assess the performance of such…

Signal Processing · Electrical Eng. & Systems 2021-01-29 Mattia Lecci , Paolo Testolina , Marco Giordani , Michele Polese , Tanguy Ropitault , Camillo Gentile , Neeraj Varshney , Anuraag Bodi , Michele Zorzi

The diffusive motion of charged particles in synthetic magnetic turbulence with different properties is investigated by using numerical simulations with unprecedented dynamical range, which allow us to ensure that both the inertial range…

High Energy Astrophysical Phenomena · Physics 2020-11-24 Andrej Dundovic , Oreste Pezzi , Pasquale Blasi , Carmelo Evoli , William H. Matthaeus

This work presents a high-resolution, ray-tracing-based channel modeling for Low Earth Orbit (LEO) satellite-to-ground links in a suburban environment at X-band. Using simulations conducted in Wireless InSite, we develop a parametric…

Signal Processing · Electrical Eng. & Systems 2025-07-22 Wahab Khawaja , Ismail Guvenc , Rune Hylsberg Jacobsen

A novel method for solving the linear radiative transport equation (RTE) in a three-dimensional homogeneous medium is proposed and illustrated with numerical examples. The method can be used with an arbitrary phase function A(s,s') with the…

Mathematical Physics · Physics 2007-05-23 George Panasyuk , John C. Schotland , Vadim A. Markel

This work develops novel algorithms for high-performance networking in the presence of obstacles based on a method for communicating via ultrasonic rays reflected at the obstacles. The rays are curves determined by the variable speed of…

Networking and Internet Architecture · Computer Science 2012-07-09 Kamen Lozev

Acoustic propagation models are widely used in numerous oceanic and other underwater applications. Most conventional models are approximate solutions of the acoustic wave equation, and require accurate environmental knowledge to be…

Sound · Computer Science 2023-08-25 Kexin Li , Mandar Chitre

Realistic modeling of scattering from curved metallic bodies - such as vehicles and roadside structures - is essential for cellular and vehicular channel modeling as well as radar applications. A practical approach is to approximate curved…

Signal Processing · Electrical Eng. & Systems 2026-04-08 Ainur Ziganshin , Enrico M. Vitucci , Wim Kotterman , Reiner Thomae , Christian Schneider , Vittorio Degli-Esposti

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

A striking prediction from the random matrix theory in mesoscopic physics is the existence of "open channels": waves that can use multipath interference to achieve perfect transmission across an opaque disordered medium even in the…

Optics · Physics 2024-06-12 Ho-Chun Lin , Chia Wei Hsu

We present a new ray bending approach, referred to as the Eigenray method, for solving two-point boundary-value kinematic and dynamic ray tracing problems in 3D smooth heterogeneous general anisotropic elastic media. The proposed Eigenray…

Geophysics · Physics 2020-03-23 Zvi Koren , Igor Ravve

We propose a new technique for a-posteriori diffusion analysis of numerical schemes. The scalar linear advection equation with a broadband signal as initial conditions is numerically solved to simulate a traveling linear wave. A diffusion…

Computational Physics · Physics 2017-07-18 S. M. Joshi , A. Chatterjee

We show the necessity for a new approach towards comprehensive and consistent simulations of the propagation of galactic cosmic rays. Our developments are optimised for addressing the spatially 3-dimensional inhomogeneous diffusion problem…

Instrumentation and Methods for Astrophysics · Physics 2013-08-14 M. Werner , R. Kissmann , A. W. Strong , O. Reimer