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相关论文: Measuring angular diameters of extended sources

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In this paper we study the problem of density deconvolution under general assumptions on the measurement error distribution. Typically deconvolution estimators are constructed using Fourier transform techniques, and it is assumed that the…

统计理论 · 数学 2020-02-04 Denis Belomestny , Alexander Goldenshluger

A concise method of deriving expressions for Gaussian-like solutions of the paraxial and d'Alembert equations is presented. This method is based on the Hankel transform. Choosing some Gaussian base functions with slight modifications of the…

光学 · 物理学 2021-12-07 Tomasz Radożycki

Image analysis methods that are based on exact blur values are faced with the computational complexities due to blur measurement error. This atmosphere encourages scholars to look for handcrafted and learned features for finding depth from…

计算机视觉与模式识别 · 计算机科学 2017-09-04 Akbar Saadat

Estimating the angular separation between two incoherent thermal sources is a challenging task for direct imaging, especially when it is smaller than or comparable to the Rayleigh length. In addition, the task of discriminating whether…

量子物理 · 物理学 2025-06-23 Ugo Zanforlin , Cosmo Lupo , Peter W. R. Connolly , Pieter Kok , Gerald S. Buller , Zixin Huang

A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the…

计算机视觉与模式识别 · 计算机科学 2015-03-19 Xiaopeng Xu , Xiaochun Zhang

We present a new method of transient point source deconvolution for coded-aperture X-Ray detectors. Our method is based upon the calculation of the likelihood function and its interpretation as a probability density for the transient source…

天体物理学 · 物理学 2008-02-03 Carlo Graziani , Donald Q. Lamb , Raphael Slawinski

The flux density from undetected sources in the observing beam of a telescope produces source confusion noise in the resulting maps of the sky, and thus limits sensitivity. In a recent paper we discussed this effect in the…

天体物理学 · 物理学 2007-05-23 A. W. Blain , R. J. Ivison , Ian Smail , J. -P. Kneib

To determine the magnification of an extended source caused by gravitational lensing one has to perform a two-dimensional integral over point-source magnifications in general. Since the point-source magnification jumps to an infinite value…

天体物理学 · 物理学 2011-05-23 M. Dominik

The parametric fluorescence from a nonlinear crystal forms a conical radiation pattern. We measure the angular and spectral distributions of parametric fluorescence in a beta-barium borate crystal pumped by a 405-nm diode laser employing…

光学 · 物理学 2013-10-04 Feng-kuo Hsu , Chih-Wei Lai

We introduce a unified approach that, given a strong gravitationally lensed polarised source, self-consistently infers its complex surface brightness distribution and the lens galaxy mass-density profile, magnetic field and electron density…

星系天体物理 · 物理学 2024-07-30 S. Ndiritu , S. Vegetti , D. M. Powell , J. P. McKean

The density deconvolution problem involves recovering a target density g from a sample that has been corrupted by noise. From the perspective of Le Cam's local asymptotic normality theory, we show that non-parametric density deconvolution…

统计理论 · 数学 2015-07-06 Stefan Wager

X-ray sources with very few counts can be identified with low-noise X-ray detectors such as ACIS onboard the Chandra X-ray Observatory. These sources are often too faint for parametric spectral modeling using well-established methods such…

太阳与恒星天体物理 · 物理学 2014-11-20 Konstantin V. Getman , Eric D. Feigelson , Patrick S. Broos , Leisa K. Townsley , Gordon P. Garmire

The imaging performance of tomographic deconvolution phase microscopy can be described in terms of the phase optical transfer function (POTF) which, in turn, depends on the illumination profile. To facilitate the optimization of the…

光学 · 物理学 2021-05-12 Jianhui Huang , Yijun Bao , Thomas K. Gaylord

Fourier transform is applied to annular beams of simplified flat two-level geometry: bright outer ring with a darker core. The pattern of focal beam profile (i.e. far field) is calculated and characterized with respect of its intensity…

光学 · 物理学 2009-04-14 D. N. Astadjov

Microscopy is one of the most essential imaging techniques in life sciences. High-quality images are required in order to solve (potentially life-saving) biomedical research problems. Many microscopy techniques do not achieve sufficient…

计算机视觉与模式识别 · 计算机科学 2018-10-24 Joris Roels , Jan Aelterman , Jonas De Vylder , Hiep Luong , Yvan Saeys , Wilfried Philips

Deconvolution is the most commonly used image processing method to remove the blur caused by the point-spread-function (PSF) in optical imaging systems. While this method has been successful in deblurring, it suffers from several…

图像与视频处理 · 电气工程与系统科学 2019-10-10 Huangxuan Zhao , Ziwen Ke , Ningbo Chen , Ke Li , Lidai Wang , Xiaojing Gong , Wei Zheng , Liang Song , Zhicheng Liu , Dong Liang , Chengbo Liu

We provide efficient and intuitive tools for deriving bounds on achievable precision in quantum enhanced metrology based on the geometry of quantum channels and semi-definite programming. We show that when decoherence is taken into account,…

量子物理 · 物理学 2012-09-19 Rafal Demkowicz-Dobrzanski , Jan Kolodynski , Madalin Guta

The Depth from Defocus (DFD) imaging technique for measuring the size and number concentration of particles in a dispersed two-phase flow has up to now been restricted to relatively sparse particle densities and to identifying only…

流体动力学 · 物理学 2024-04-01 Rixin Xua , Zuojie Huanga , Wenchao Gonga , Wu Zhoua , Cameron Tropea

Deconvolution is essential for radio interferometric imaging to produce scientific quality data because of finite sampling in the Fourier plane. Most deconvolution algorithms are based on CLEAN which uses a grid of image pixels, or clean…

天体物理仪器与方法 · 物理学 2016-11-18 Sarod Yatawatta

We demonstrate the transformation of Gaussian input beams into super-Gaussian beams with a quasi flat-top transverse profile by means of the conical refraction phenomenon by adjusting the ratio between the ring radius and the waist radius…

光学 · 物理学 2015-01-27 A. Turpin , Yu. V. Loiko , T. K. Kalkandkiev , H. Tomizawa , J. Mompart