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The Fourier spectral techniques that are common in Astronomy for analyzing periodic or multi-periodic light-curves lose their usefulness when they are applied to unsteady light-curves. We review some of the novel techniques that have been…

Astrophysics · Physics 2016-01-27 J. Robert Buchler , Zoltan Kollath

The image subtraction method is a powerful tool to analyze the light variations in crowded fields. This method is able to achieve a nearly optimal differential photometry, even in very dense regions. However, image subtraction is not…

Astrophysics · Physics 2007-05-23 C. Alard

Photon-subtracted and photon-added Gaussian states are amongst the simplest non-Gaussian states that are experimentally available. It is generally believed that they are some of the best candidates to enhance sensitivity in parameter…

Quantum Physics · Physics 2014-07-23 Daniel Braun , Pu Jian , Olivier Pinel , Nicolas Treps

Astrometric detection and mass determination of Earth-mass exoplanets requires sub-microarcsec accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must…

We present $\mathcal{O}(N^2)$ estimators for the small-scale power spectrum and bispectrum in cosmological simulations. In combination with traditional methods, these allow spectra to be efficiently computed across a vast range of scales,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-21 Oliver H. E. Philcox

Though Fourier Transforms (FTs) are a common technique for finding correlation functions, they are not typically used in computations of the anisotropy of the two-point correlation function (2PCF) about the line of sight in wide-angle…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Zachary Slepian , Daniel J. Eisenstein

Fourier ptychographic microscopy enables gigapixel-scale imaging, with both large field-of-view and high resolution. Using a set of low-resolution images that are recorded under varying illumination angles, the goal is to computationally…

Signal Processing · Electrical Eng. & Systems 2018-03-13 Emrah Bostan , Mahdi Soltanolkotabi , David Ren , Laura Waller

Fast Fourier Transform based phase screen simulations give accurate results only when the screen size ($G$) is much larger than the outer scale parameter ($L_0$). Otherwise, they fall short in correctly predicting both the low and high…

Instrumentation and Methods for Astrophysics · Physics 2021-06-03 Sorabh Chhabra , Jyotirmay Paul , Anamparambu N. Ramaprakash , Avinash Surendran

The intersection of Astronomy and AI encounters significant challenges related to issues such as noisy backgrounds, lower resolution (LR), and the intricate process of filtering and archiving images from advanced telescopes like the James…

Computer Vision and Pattern Recognition · Computer Science 2024-05-24 Mohammed Talha Alam , Raza Imam , Mohsen Guizani , Fakhri Karray

A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not…

Astrophysics · Physics 2008-11-26 Z. Shkedy , L. Decin , G. Molenberghs , C. Aerts

Transforming the instrumental photometry of ground-based telescopes into a calibrated physical flux in a well-defined passband is a major challenge in astronomy. Along with the intrinsic instrumental difference between telescopes sharing…

Instrumentation and Methods for Astrophysics · Physics 2025-07-08 S. Garrappa , E. O. Ofek , S. Ben-Ami , D. Polishook , A. Gal-Yam , Y. Shvartzvald , A. Krassilchtchikov , R. Konno , E. Segre , Y. M. Shani , Y. Sofer-Rimalt , M. Engel , A. Blumenzweig

The EFAR project is a study of 736 candidate early-type galaxies in 84 clusters lying in two regions towards Hercules-Corona Borealis and Perseus-Cetus at distances $cz \approx 6000-15000$ km/s. In this paper we describe a new method of…

Estimating the diagonal entries of a matrix, that is not directly accessible but only available as a linear operator in the form of a computer routine, is a common necessity in many computational applications, especially in image…

Instrumentation and Methods for Astrophysics · Physics 2015-03-19 Marco Selig , Niels Oppermann , Torsten A. Enßlin

This paper addresses the issue of detecting point objects in a clutter background and estimating their position by image processing. We are interested in the specific context where the object signature significantly varies with its random…

Applications · Statistics 2009-11-09 Vincent Samson , Frédéric Champagnat , Jean-François Giovannelli

The extended source effect on microlensing magnification is non-negligible and must be taken into account for in an analysis of microlensing. However, the evaluation of the extended source magnification is numerically expensive because it…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 Sunao Sugiyama

Images taken with modern detectors require calibration via flat fielding to obtain the same flux scale across the whole image. One method for obtaining the best possible flat fielding accuracy is to derive a photometric model from dithered…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Lodovico Coccato , Daniel M. Bramich , Wolfram Freudling , Sabine Moehler

We present new data processing techniques that allow to correct the main instrumental effects that degrade the images obtained by ISOCAM, the camera on board the Infrared Space Observatory (ISO). Our techniques take advantage of the fact…

Astrophysics · Physics 2009-10-31 M. -A. Miville-Deschenes , F. Boulanger , A. Abergel , J. -P. Bernard

Interferometry is a powerful technique for making sensitive, high-fidelity images of the sky, but is limited in its ability to measure extended or diffuse emission. Better images of extended astronomical objects can be obtained by…

Instrumentation and Methods for Astrophysics · Physics 2020-06-12 Brian S. Mason

The MOST (Microvariability & Oscillations of STars) satellite obtains ultraprecise photometry from space with high sampling rates and duty cycles. Astronomical photometry or imaging missions in low Earth orbits, like MOST, are especially…

The convolution of galaxy images by the point-spread function (PSF) is the dominant source of bias for weak gravitational lensing studies, and an accurate estimate of the PSF is required to obtain unbiased shape measurements. The PSF…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Martin Eriksen , Henk Hoekstra