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We present considerations about the transverse beam transfer function (BTF) of beams under the influence of two effects: The strong-strong beam-beam effect and the influence of a Gaussian electron lens. The BTF are investigated using two…

Accelerator Physics · Physics 2014-10-22 P. Gorgen , O. Boine-Frankenheim , W. Fischer

We introduce a phase imaging mechanism for scanning transmission electron microscopy that exploits the complementary intensity changes of transmitted disks at different scattering angles. For scanning transmission electron microscopy, this…

Instrumentation and Detectors · Physics 2023-07-06 Binbin Wang , David W. McComb

We demonstrate a 13-fold speed improvement in broadband cantilever-enhanced photoacoustic spectroscopy (CEPAS) by combining it with phase-controlled Fourier-transform spectroscopy (PC-FTS) instead of traditional Fourier-transform infrared…

Optics · Physics 2022-12-21 Santeri Larnimaa , Mikhail Roiz , Markku Vainio

CNNs perform remarkably well when the training and test distributions are i.i.d, but unseen image corruptions can cause a surprisingly large drop in performance. In various real scenarios, unexpected distortions, such as random noise,…

Computer Vision and Pattern Recognition · Computer Science 2021-03-31 Tonmoy Saikia , Cordelia Schmid , Thomas Brox

A new technique for maintaining high contrast in an atom interferometer is used to measure large de Broglie wave phase shifts. Dependence of an interaction induced phase on the atoms' velocity is compensated by applying an engineered…

Quantum Physics · Physics 2009-11-10 Tony D. Roberts , Alexander D. Cronin , Martin V. Tiberg , David E. Pritchard

We identify a systematic distortion of the gain-vs.-frequency function of radio telescopes caused by digital flattening ("whitening") of the signal's spectrum followed by re-quantization, a common pair of processes in the signal processing…

Instrumentation and Methods for Astrophysics · Physics 2026-05-08 Ruby Byrne , Larry R. D'Addario , Daniel C. Jacobs , Gregg Hallinan

Deployment of machine learning algorithms into real-world practice is still a difficult task. One of the challenges lies in the unpredictable variability of input data, which may differ significantly among individual users, institutions,…

Computer Vision and Pattern Recognition · Computer Science 2024-11-26 Roman Stoklasa

Accurate estimates of Instrument Spectral Response Functions (ISRFs) are crucial in order to have a good characterization of high resolution spectrometers. Spectrometers are composed of different optical elements that can induce errors in…

Numerical Analysis · Mathematics 2024-04-09 Jihanne El Haouari , Jean-Michel Gaucel , Christelle Pittet , Jean-Yves Tourneret , Herwig Wendt

Efficient estimators of Fourier-space statistics for large number of objects rely on Fast Fourier Transforms (FFTs), which are affected by aliasing from unresolved small scale modes due to the finite FFT grid. Aliasing takes the form of a…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Emiliano Sefusatti , Martin Crocce , Roman Scoccimarro , Hugh Couchman

The use of Wavefront Sensors (WFS) is nowadays fundamental in the field of instrumental optics. This paper discusses the principle of an original and recently proposed new class of WFS. Their principle consists in evaluating the slopes of…

Optics · Physics 2011-05-23 Francois Henault

Precise centroid estimation plays a critical role in accurate astrometry using telescope images. Conventional centroid estimation fits a template point spread function (PSF) to the image data. Because the PSF is typically not known to high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Chengxing Zhai , Mike Shao , Renaud Goullioud , Bijan Nemati

Destriping methods for constructing maps of the Cosmic Microwave Background (CMB) anisotropies have been investigated extensively in the literature. However, their error properties have been studied in less detail. Here we present an…

Astrophysics · Physics 2009-11-10 G. Efstathiou

Phase aberration is one of the main contributors to image degradation in ultrasound imaging. Normalized-Cross-Correlation (NCC) is one of the most extensively studied techniques to estimate the arrival delay error and the aberration…

Medical Physics · Physics 2021-06-22 Dena Monjazebi , Yuan Xu

As a multi-contrast X-ray computed tomography (CT) imaging system, the grating-based Talbot-Lau interferometer is able to generate the absorption contrast and differential phase contrast (DPC) images concurrently. However, experiments found…

Medical Physics · Physics 2024-04-16 Yuhang Tan , Jiecheng Yang , Hairong Zheng , Dong Liang , Peiping Zhu , Yongshuai Ge

Field distortion is widespread in imaging systems. If it cannot be measured and corrected well, it will affect the accuracy of photogrammetry. To this end, we proposed a general field distortion model based on Fredholm integration, which…

Image and Video Processing · Electrical Eng. & Systems 2022-05-19 Yunqi Sun , Jianfeng Zhou

21cm tomography promises to be a powerful tool for estimating cosmological parameters, constraining the epoch of reionization, and probing the so-called dark ages. However, realizing this promise will require the extraction of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Adrian Liu , Max Tegmark

Improving the phase resolution of interferometry is crucial for high-precision measurements of various physical quantities. Systematic phase errors dominate the phase uncertainties in most realistic optical interferometers. Here we propose…

Quantum Physics · Physics 2018-04-03 Li Li , Yuan Li , You-Lang Zhang , Sixia Yu , Chao-Yang Lu , Nai-Le Liu , Jun Zhang , Jian-Wei Pan

We discuss the derivation of the analytic properties of the cross-power spectrum estimator from multi-detector CMB anisotropy maps. The method is computationally convenient and it provides unbiased estimates under very broad assumptions. We…

Astrophysics · Physics 2007-05-23 G. Polenta , D. Marinucci , A. Balbi , P. de Bernardis , E. Hivon , S. Masi , P. Natoli , N. Vittorio

The Perception-Distortion tradeoff (PD-tradeoff) theory suggests that face restoration algorithms must balance perceptual quality and fidelity. To achieve minimal distortion while maintaining perfect perceptual quality, Posterior-Mean…

Computer Vision and Pattern Recognition · Computer Science 2025-07-02 Xin Luo , Menglin Zhang , Yunwei Lan , Tianyu Zhang , Rui Li , Chang Liu , Dong Liu

The use of multitaper estimates for spectral proper orthogonal decomposition (SPOD) is explored. Multitaper and multitaper-Welch estimators that use discrete prolate spheroidal sequences (DPSS) as orthogonal data windows are compared to the…

Fluid Dynamics · Physics 2022-09-14 Oliver T. Schmidt