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相关论文: Smoothing of an All-sky Survey Map with a Fisher-v…

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In this paper, we compare two optimization algorithms using full Hessian and approximation Hessian to obtain numerical spherical designs through their variational characterization. Based on the obtained spherical design point sets, we…

数值分析 · 数学 2024-01-03 Yuchen Xiao , Xiaosheng Zhuang

Forecast verification plays a crucial role in the development cycle of operational numerical weather prediction models. At the same time, verification remains a challenge as the traditionally used non-spatial forecast quality metrics…

大气与海洋物理 · 物理学 2026-05-25 Gregor Skok , Katarina Kosovelj

We study an estimator for smoothing irregularly sampled data into a smooth map. The estimator has been widely used in astronomy, owing to its low level of noise; it involves a weight function -- or smoothing kernel -- w(\theta). We show…

天体物理学 · 物理学 2009-11-06 Marco Lombardi , Peter Schneider

Removing the aberrations introduced by the Point Spread Function (PSF) is a fundamental aspect of astronomical image processing. The presence of noise in observed images makes deconvolution a nontrivial task that necessitates the use of…

天体物理仪器与方法 · 物理学 2017-05-03 Samuel Farrens , Jean-Luc Starck , Fred Maurice Ngolè Mboula

We present a versatile formulation of the convolution operation that we term a "mapped convolution." The standard convolution operation implicitly samples the pixel grid and computes a weighted sum. Our mapped convolution decouples these…

计算机视觉与模式识别 · 计算机科学 2019-06-27 Marc Eder , True Price , Thanh Vu , Akash Bapat , Jan-Michael Frahm

We study the problem of deconvolution for light-sheet microscopy, where the data is corrupted by spatially varying blur and a combination of Poisson and Gaussian noise. The spatial variation of the point spread function (PSF) of a…

Obtaining constraints from the largest scales of a galaxy survey is challenging due to the survey mask allowing only partial measurement of large angular modes. This scatters information from the harmonic-space 2-point function away from…

宇宙学与河外天体物理 · 物理学 2022-02-16 Henry S. Grasshorn Gebhardt , Olivier Doré

An important application of next-generation wide-field radio interferometers is making high dynamic range maps of radio emission. Traditional deconvolution methods like CLEAN can give poor recovery of diffuse structure, prompting the…

天体物理仪器与方法 · 物理学 2024-10-23 Katrine A. Glasscock , Philip Bull , Jacob Burba , Hugh Garsden , Michael J. Wilensky

This paper introduces a general method to approximate the convolution of an arbitrary program with a Gaussian kernel. This process has the effect of smoothing out a program. Our compiler framework models intermediate values in the program…

图形学 · 计算机科学 2017-06-06 Yuting Yang , Connelly Barnes

A collection of algorithms is described for numerically computing with smooth functions defined on the unit sphere. Functions are approximated to essentially machine precision by using a structure-preserving iterative variant of Gaussian…

数值分析 · 数学 2016-04-05 Alex Townsend , Heather Wilber , Grady B. Wright

In this manuscript, we study the nearly flat approximation of a conformally invariant gravitational theory in metric measure space (MMS). In addition, we investigate the transformation of the energy-momentum tensor in this context and…

广义相对论与量子宇宙学 · 物理学 2023-02-28 Samaneh Oghbaiee , Nafiseh Rahmanpour , Hossein Shojaie

A new technique is presented for producing images from interferometric data. The method, ``smear fitting'', makes the constraints necessary for interferometric imaging double as a model, with uncertainties, of the sky brightness…

天体物理学 · 物理学 2009-11-11 Robert I. Reid

It has been shown that the large--scale correlation functions of the density field (and velocity divergence field) follow a specific hierarchy in the quasilinear regime and for Gaussian initial conditions (Bernardeau 1992). The exact…

天体物理学 · 物理学 2007-05-23 F. Bernardeau

In this work we introduced a new proposal to study the gravitational lensing theory by spherical lenses, starting from its surface mass density $\Sigma(x)$ written in terms of a decreasing function $f$ of a dimensionless coordinate $x$ on…

宇宙学与河外天体物理 · 物理学 2014-07-21 Roger Hurtado , Leonardo Castaneda , Juan M. Tejeiro

The estimation of potential fields such as the gravitational or magnetic potential at the surface of a spherical planet from noisy observations taken at an altitude over an incomplete portion of the globe is a classic example of an…

统计理论 · 数学 2009-11-11 Frederik J Simons , F. A. Dahlen

Convergence maps of the integrated matter distribution are a key science result from weak gravitational lensing surveys. To date, recovering convergence maps has been performed using a planar approximation of the celestial sphere. However,…

宇宙学与河外天体物理 · 物理学 2021-12-16 Christopher G. R. Wallis , Matthew A. Price , Jason D. McEwen , Thomas D. Kitching , Boris Leistedt , Antoine Plouviez

In this article, we show that (i) any smooth function on compact Riemann surface with non-empty smooth boundary $ (M, \partial M, g) $ can be realized as a Gaussian curvature function; (ii) any smooth function on $ \partial M $ can be…

偏微分方程分析 · 数学 2023-04-11 Jie Xu

We prove Richberg type theorem for $m$-subharmonic function. The main tool is the complex Hessian equation for which we obtain the existence of the unique smooth solution in strictly pseudoconvex domains.

复变函数 · 数学 2014-04-24 Szymon Pliś

A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be…

天体物理学 · 物理学 2009-10-30 P. Magain , F. Courbin , S. Sohy

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…

天体物理学 · 物理学 2009-11-10 M. Tristram , J. -C. Hamilton , J. F. Macias-Perez , C. Renault
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