English
Related papers

Related papers: A Comparison Between Lucky Imaging and Speckle Sta…

200 papers

The LSST survey will provide unprecedented statistical power for measurements of dark energy. Consequently, controlling systematic uncertainties is becoming more important than ever. The LSST observing strategy will affect the statistical…

Angular differential imaging is a high-contrast imaging technique that reduces quasi-static speckle noise and facilitates the detection of nearby companions. A sequence of images is acquired with an altitude/azimuth telescope while the…

Astrophysics · Physics 2009-11-13 C. Marois , D. Lafreniere , R. Doyon , B. Macintosh , D. Nadeau

Ultrasound is a widely used medical tool for non-invasive diagnosis, but its images often contain speckle noise which can lower their resolution and contrast-to-noise ratio. This can make it more difficult to extract, recognize, and analyze…

Image and Video Processing · Electrical Eng. & Systems 2024-03-06 Suraj Bhute , Subhamoy Mandal , Debashree Guha

Speckle is an intrinsic pattern in optical coherence tomography (OCT) that obscures fine image features and degrades effective resolution. In this study, we propose a numerical speckle reduction method based on the dispersed scatterer model…

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

Instrumentation and Methods for Astrophysics · Physics 2022-08-12 E. Gallego-Cano , R. Schödel , A. T. Gallego-Calvente , A. M. Ghez

Strong lensing time delay cosmography has excellent complementarity with other dark energy probes, and will soon have abundant systems detected. We investigate two issues in the imaging and spectroscopic followup required to obtain the time…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Eric V. Linder

Context. Strong lensing mass measurements require the knowledge of the redshift of both the lens and the source galaxy. Traditionally, spectroscopic redshifts are used for this purpose. Upcoming surveys, however, will lead to the discovery…

Astrophysics of Galaxies · Physics 2022-04-15 Alessandro Sonnenfeld

We study the influence rules of the speckle size of light source on ghost imaging, and propose a new type of speckle patterns to improve the quality of ghost imaging. The results show that the image quality will first increase and then…

Stereoscopic spectral imaging is an observing technique that affords rapid acquisition of limited spectral information over an entire image plane simultaneously. Light from a telescope is dispersed into multiple spectral orders, which are…

Astrophysics · Physics 2007-05-23 Craig E. DeForest , Charles C. Kankelborg

Speckle photography can be used to monitor deformations of solid surfaces. The measuring characteristics, such as range or lateral resolution depend heavily on the optical recording and illumination set-up. This paper shows how, by the…

Optics · Physics 2014-01-30 Jose M. Diazdelacruz

Natural images tend to mostly consist of smooth regions with individual pixels having highly correlated spectra. This information can be exploited to recover hyperspectral images of natural scenes from their incomplete and noisy…

Computer Vision and Pattern Recognition · Computer Science 2016-11-03 Reza Arablouei , Frank de Hoog

Just as turbulence in the Earth's atmosphere can severely limit the angular resolution of optical telescopes, turbulence in the ionized interstellar medium fundamentally limits the resolution of radio telescopes. We present a scattering…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 Michael D. Johnson

The highest resolution images ever taken in the visible were obtained by combining Lucky Imaging and low order adaptive optics. This paper describes a new instrument to be deployed on the WHT 4.2m and GTC 10.4 m telescopes on La Palma, with…

We present a new processing technique aimed at significantly improving the angular differential imaging method (ADI) in the context of high-contrast imaging of faint objects nearby bright stars in observations obtained with extreme adaptive…

Instrumentation and Methods for Astrophysics · Physics 2017-11-15 Gianluca Li Causi , Marco Stangalini , Simone Antoniucci , Fernando Pedichini , Massimiliano Mattioli , Vincenzo Testa

This paper is concerned with the theoretical properties of high contrast coronagraphic images in the context of exoplanet searches. We derive and analyze the statistical properties of the residual starlight in coronagraphic images, and…

Astrophysics · Physics 2009-11-13 Rémi Soummer , André Ferrari , Claude Aime , Laurent Jolissaint

The price of instruments and observing time on modern telescopes is quickly increasing with the size of the primary mirror. Therefore, it is worth revisiting the data reduction algorithms to extract every bit of scientific information from…

Instrumentation and Methods for Astrophysics · Physics 2021-02-03 Nikolai Piskunov , Ansgar Wehrhahn , Thomas Marquart

The observations of solar photosphere from the ground encounter significant problems due to the presence of Earth's turbulent atmosphere. Prior to applying image reconstruction techniques, the frames obtained in most favorable atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2017-12-20 Adam Popowicz , Krystian Radlak , Krzysztof Bernacki , Valeri Orlov

In the past years modern mathematical methods for image analysis have led to a revolution in many fields, from computer vision to scientific imaging. However, some recently developed image processing techniques successfully exploited by…

Instrumentation and Methods for Astrophysics · Physics 2015-01-19 Marco Castellano , Daniele Ottaviani , Adriano Fontana , Emiliano Merlin , Stefano Pilo , Maurizio Falcone

Purpose: Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. The authors have investigated a photon-counting spectral…

Medical Physics · Physics 2021-01-21 Erik Fredenberg , Magnus Hemmendorff , Bjorn Cederstrom , Magnus Aslund , Mats Danielsson

Stacking analysis is a means of detecting faint sources using a priori position information to estimate an aggregate signal from individually undetected objects. Confusion severely limits the effectiveness of stacking in deep surveys with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Peter Kurczynski , Eric Gawiser