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Related papers: Fast Convolution on the Sphere

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We present a general method for accelerating by more than an order of magnitude the convolution of pixelated function on the sphere with a radially-symmetric kernel. Our method splits the kernel into a compact real-space, and a compact…

Instrumentation and Methods for Astrophysics · Physics 2012-11-16 P. M. Sutter , Benjamin D. Wandelt , Franz Elsner

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

We present a general method for accelerating by more than an order of magnitude the convolution of pixelated functions on the sphere with a radially-symmetric kernel. Our method splits the kernel into a compact real-space component and a…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-31 P. M. Sutter , Benjamin D. Wandelt , Franz Elsner

We describe a fast and accurate method to perform the convolution of a sky map with a general asymmetric main beam along any given scanning strategy. The method is based on the decomposition of the beam as a sum of circular functions, here…

Astrophysics · Physics 2009-11-10 M. Tristram , J. -C. Hamilton , J. F. Macias-Perez , C. Renault

We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The…

Instrumentation and Methods for Astrophysics · Physics 2014-01-08 F. Elsner , B. D. Wandelt

We describe a accurate and fast pixel-based statistical method to interpolate fields of arbitrary spin on the sphere. We call this method Fast and Lean Interpolation on the Sphere (FLINTS). The method predicts the optimal interpolated…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-21 Guilhem Lavaux , Benjamin D. Wandelt

Image subtraction in astronomy is a tool for transient object discovery such as asteroids, extra-solar planets and supernovae. To match point spread functions (PSFs) between images of the same field taken at different times a convolution…

Instrumentation and Methods for Astrophysics · Physics 2013-05-30 Steven Hartung , Hemant Shukla , J. Patrick Miller , Carlton Pennypacker

We present several diverse applications of the spherical fast convolution method suggested by Wandelt and Gorski (2001), which is useful for studies of telescope optical properties and for construction of shaped filters for analysis of…

Astrophysics · Physics 2007-09-18 K. M. Huffenberger , I. J. O'Dwyer , K. M. Gorski , B. D. Wandelt

Precise measurement of the angular power spectrum of the Cosmic Microwave Background (CMB) temperature and polarization anisotropy can tightly constrain many cosmological models and parameters. However, accurate measurements can only be…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 S. Mitra , G. Rocha , K. M. Górski , K. M. Huffenberger , H. K. Eriksen , M. A. J. Ashdown , C. R. Lawrence

We present a fast algorithm for generating full sky, high resolution ($\sim 5'$) simulations of the CMB anisotropy pattern. We also discuss the inverse problem, that of evaluating from such a map the full set of $a_{\ell m}$'s and the…

Astrophysics · Physics 2014-10-13 Pio Francesco Muciaccia , Paolo Natoli , Nicola Vittorio

We discuss all-sky convolution of the instrument beam with the sky signal in polarimetry experiments, such as the Planck mission which will map the temperature anisotropy and polarization of the cosmic microwave background (CMB). To account…

The Cosmic Microwave Background (CMB) data analysis and the map-making process rely heavily on the use of spherical harmonics. For suitable pixelizations of the sphere, the (forward and inverse) Fourier transform plays a crucial role in…

We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Nicoletta Krachmalnicoff , Maurizio Tomasi

Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Mariona Giner Mascarell , Emory F. Bunn

State-of-the-art 2D image compression schemes rely on the power of convolutional neural networks (CNNs). Although CNNs offer promising perspectives for 2D image compression, extending such models to omnidirectional images is not…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 Navid Mahmoudian Bidgoli , Roberto G. de A. Azevedo , Thomas Maugey , Aline Roumy , Pascal Frossard

A fast algorithm is developed for the directional correlation of scalar band-limited signals and band-limited steerable filters on the sphere. The asymptotic complexity associated to it through simple quadrature is of order O(L^5), where 2L…

Astrophysics · Physics 2011-02-11 Y. Wiaux , L. Jacques , P. Vielva , P. Vandergheynst

We present a new computationally efficient method for multi-beamforming in the broadband setting. Our "fast beamspace transformation" forms $B$ beams from $M$ sensor outputs using a number of operations per sample that scales linearly (to…

Signal Processing · Electrical Eng. & Systems 2026-04-17 Nakul Singh , Coleman DeLude , Mark Davenport , Justin Romberg

Spherical CNNs generalize CNNs to functions on the sphere, by using spherical convolutions as the main linear operation. The most accurate and efficient way to compute spherical convolutions is in the spectral domain (via the convolution…

Machine Learning · Computer Science 2023-06-09 Carlos Esteves , Jean-Jacques Slotine , Ameesh Makadia

Szapudi et al (2001) introduced the method of estimating angular power spectrum of the CMB sky via heuristically weighted correlation functions. Part of the new technique is that all (co)variances are evaluated by massive Monte Carlo…

Astrophysics · Physics 2007-05-23 I. Szapudi , S. Prunet , S. Colombi

Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty…

Instrumentation and Methods for Astrophysics · Physics 2011-08-22 J. D. McEwen , Y. Wiaux , D. M. Eyers
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