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Related papers: Spherical Harmonic Amplitudes From Grid Data

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A method is described by which a function defined on a cubic grid (as from a finite difference solution of a partial differential equation) can be resolved into spherical harmonic components at some fixed radius. This has applications to…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Charles W. Misner

Computing spherical harmonic decompositions is a ubiquitous technique that arises in a wide variety of disciplines and a large number of scientific codes. Because spherical harmonics are defined by integrals over spheres, however, one must…

General Relativity and Quantum Cosmology · Physics 2015-06-25 David R. Fiske

Accurate estimation of the sound field around a rigid sphere necessitates adequate sampling on the sphere, which may not always be possible. To overcome this challenge, this paper proposes a method for sound field estimation based on a…

Audio and Speech Processing · Electrical Eng. & Systems 2023-07-27 Xingyu Chen , Fei Ma , Amy Bastine , Prasanga Samarasinghe , Huiyuan Sun

This paper presents a method for the approximation of harmonic potentials that combines downward continuation of globally available data on a sphere $\Omega_R$ of radius $R$ (e.g., a satellite's orbit) with locally available data on a…

Numerical Analysis · Mathematics 2015-07-07 Christian Gerhards

Recent microscopy imaging techniques allow to precisely analyze cell morphology in 3D image data. To process the vast amount of image data generated by current digitized imaging techniques, automated approaches are demanded more than ever.…

Computer Vision and Pattern Recognition · Computer Science 2020-10-26 Dennis Eschweiler , Malte Rethwisch , Simon Koppers , Johannes Stegmaier

In this paper a local approximation method on the sphere is presented. As interpolation scheme we consider a partition of unity method, such as the modified spherical Shepard's method, which uses zonal basis functions (ZBFs) plus spherical…

Numerical Analysis · Mathematics 2014-04-08 Alessandra De Rossi

We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are…

Astrophysics · Physics 2009-11-13 F. A. Dahlen , Frederik J Simons

For the accurate representation and reconstruction of band-limited signals on the sphere, an optimal-dimensionality sampling scheme has been recently proposed which requires the optimal number of samples equal to the number of degrees of…

Information Theory · Computer Science 2017-09-11 Wajeeha Nafees , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

In this short note we propose a new method for construction new nice arrangement on the sphere $S^d$ using the spaces of spherical harmonic.

Metric Geometry · Mathematics 2008-11-27 Andriy Bondarenko

In this paper, we study hybrid neural representations for spherical data, a domain of increasing relevance in scientific research. In particular, our work focuses on weather and climate data as well as comic microwave background (CMB) data.…

Machine Learning · Computer Science 2024-02-12 Hyomin Kim , Yunhui Jang , Jaeho Lee , Sungsoo Ahn

We derive a compressive sampling method for acoustic field reconstruction using field measurements on a predefined spherical grid that has theoretically guaranteed relations between signal sparsity, measurement number, and reconstruction…

Signal Processing · Electrical Eng. & Systems 2023-07-19 Marc Andrew Valdez , Alex J. Yuffa , Michael B. Wakin

We present a harmonic model for the data analysis of an all-sky cosmic microwave background survey, such as Planck, where the survey is obtained through ring-scans of the sky. In this model, resampling and pixelisation of the data are…

The analysis of whole-sky galaxy surveys commonly suffers from the problems of shot-noise and incomplete sky coverage (e.g. at the Zone of Avoidance). The orthogonal set of spherical harmonics is utilized here to expand the observed galaxy…

Astrophysics · Physics 2009-10-22 O. Lahav , K. B. Fisher , Y. Hoffman , C. A. Scharf , S. Zaroubi

Potential magnetic field solutions can be obtained based on the synoptic magnetograms of the Sun. Traditionally, a spherical harmonics decomposition of the magnetogram is used to construct the current and divergence free magnetic field…

Solar and Stellar Astrophysics · Physics 2011-05-02 Gabor Toth , Bart van der Holst , Zhenguang Huang

We present in this paper a spectrally accurate numerical method for computing the spherical/vector spherical harmonic expansion of a function/vector field with given (elemental) nodal values on a spherical surface. Built upon suitable…

Numerical Analysis · Mathematics 2017-09-18 Bo Wang , Li-Lian Wang , Ziqing Xie

The transport of charged particles or photons in a scattering medium can be modelled with a Boltzmann equation. The mathematical treatment for scattering in such scenarios is often simplified if evaluated in a frame where the scattering…

Plasma Physics · Physics 2024-02-27 Nils W. Schween , Brian Reville

We present the generalized iterative residual fitting (IRF) for the computation of the spherical harmonic transform (SHT) of band-limited signals on the sphere. The proposed method is based on the partitioning of the subspace of…

Information Theory · Computer Science 2017-09-11 Usama Elahi , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

Spherical harmonic expansions are well-established tools for estimating magnetic fields from surface measurements and are widely used in applications such as tomographic imaging, geomagnetism, and biomagnetism. Although the mathematical…

Instrumentation and Detectors · Physics 2026-02-24 Fynn Foerger , Philip Suskin , Marija Boberg , Jonas Faltinath , Tobias Knopp , Martin Möddel

In this pedagogically structured article, we describe a generalized harmonic formulation of the Einstein equations in spherical symmetry which is regular at the origin. The generalized harmonic approach has attracted significant attention…

General Relativity and Quantum Cosmology · Physics 2010-05-07 Evgeny Sorkin , Matthew W. Choptuik

In practice, the finite number of samples of the spherical radiation pattern or antenna gain are taken on the sphere for both the reconstruction of the antenna radiation pattern and the computation of mobile handset performance measures…

Signal Processing · Electrical Eng. & Systems 2018-12-03 Umair Ahmed , Zubair Khalid
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