English
Related papers

Related papers: A Robust Method to Measure Centroids of Spectral L…

200 papers

Measurement of stray light in a complex optical system can be a complex task. We developed a method to measure coherent stray light inside an assembled device, determining all stray light sources and their relative contribution. The method…

Optics · Physics 2026-01-30 Marco Nardello , Amaël Roubeau-Tissot , Michel Lintz

Noise measurement is a powerful tool to investigate many phenomena from laser characterization to quantum behavior of light. In this paper, we report on intensity noise measurements obtained when a laser beam is transmitted through a large…

Accurate spatio-temporal and spatio-spectral metrology is critical to the characterization and use of ultra-short, high-power lasers. The emergence of few cycle pulses, with bandwidths of tens or hundreds of nanometers, poses a significant…

Recent advances in spectroscopic instrumentation and calibration methods dramatically improve the quality of quasar spectra. Supercomputer calculations show that, at high spectral resolution, procedures used in some previous analyses of…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-15 John K. Webb , Chung-Chi Lee , Dinko Milaković

Line intensity mapping (LIM) is an emerging technique in measuring galaxy evolution and the large-scale structure of the universe. LIM surveys measure the cumulative emission from all galaxies emitting a given line at a particular redshift,…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-05 Trevor M. Oxholm

For line spectrum estimation, we derive the maximum a posteriori probability estimator where prior knowledge of frequencies is modeled probabilistically. Since the spectrum is periodic, an appropriate distribution is the circular von Mises…

Statistics Theory · Mathematics 2013-06-26 Dave Zachariah , Petter Wirfält , Magnus Jansson , Saikat Chatterjee

Light Detection and Ranging (LiDAR) technology has proven to be an important part of many robotics systems. Surface normals estimated from LiDAR data are commonly used for a variety of tasks in such systems. As most of the today's…

Robotics · Computer Science 2024-04-23 Igor Bogoslavskyi , Konstantinos Zampogiannis , Raymond Phan

Intensity mapping has been attracting increasing interest as a way to study galaxy evolution and the large scale structure of the Universe. Instead of detecting individual galaxies, we measure the integrated emission from a volume of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-13 José Fonseca

An algorithm is presented which generates pairs of oscillatory random time series which have identical periodograms but differ in the number of oscillations. This result indicate the intrinsic limitations of spectral methods when it comes…

Data Analysis, Statistics and Probability · Physics 2007-05-23 A. G. Rossberg

Spectral measurements of the 21 cm monopole background have the promise of revealing the bulk energetic properties and ionization state of our universe from z ~ 6-30. Synchrotron foregrounds are orders of magnitude larger than the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-08 Eric R. Switzer , Adrian Liu

Understanding the evolution of the Milky Way calls for the precise abundance determination of many elements in many stars. A common perception is that deriving more than a few elemental abundances ([Fe/H], [$\alpha$/Fe], perhaps [C/H],…

Solar and Stellar Astrophysics · Physics 2017-07-05 Yuan-Sen Ting , Charlie Conroy , Hans-Walter Rix , Phillip Cargile

Precision laser spectroscopy is key to many developments in atomic and molecular physics and the advancement of related technologies such as atomic clocks and sensors. However, in important spectroscopic scenarios, such as astronomy and…

Background. Astrometry at or below the micro-arcsec level with an imaging telescope assumes that the uncertainty on the location of an unresolved source can be an arbitrarily small fraction of the detector pixel, given a sufficient photon…

Instrumentation and Methods for Astrophysics · Physics 2022-12-06 Mario Gai , Alberto Vecchiato , Alberto Riva , Deborah Busonero , Mario Lattanzi , Beatrice Bucciarelli , Mariateresa Crosta , Zhaoxiang Qi

The random error of radioastronomical measurements is usually computed in the weak-signal limit, which assumes that the system temperature is sensibly the same on and off source, or with and without a spectral line. This assumption is often…

Astrophysics · Physics 2009-11-07 H. Liszt

Well-calibrated spectropolarimetry studies at resolutions of $R>$10,000 with signal-to-noise ratios (SNRs) better than 0.01\% across individual line profiles, are becoming common with larger aperture telescopes. Spectropolarimetric studies…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 David Harrington , J. R. Kuhn , Rebecca Nevin

We study the noise of the intensity variance and of the intensity correlation and structure functions measured in light scattering from a random medium in the case when these quantities are obtained by averaging over a finite number N of…

The development of sensitive large format imaging arrays for the infrared promises to provide revolutionary capabilities for space astronomy. For example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256 arrays to provide…

Astrophysics · Physics 2016-08-30 D. J. Fixsen , S. H. Moseley , R. G. Arendt

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

Optical spectroscopy plays an essential role across scientific research and industry for non-contact materials analysis1-3, increasingly through in-situ or portable platforms4-6. However, when considering low-light-level applications,…

A number of recent works have proposed to solve the line spectral estimation problem by applying off-the-grid extensions of sparse estimation techniques. These methods are preferable over classical line spectral estimation algorithms…

Signal Processing · Electrical Eng. & Systems 2018-02-19 Thomas Lundgaard Hansen , Bernard Henri Fleury , Bhaskar D. Rao
‹ Prev 1 4 5 6 7 8 10 Next ›