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Context: Combining high-contrast imaging with medium- or high-resolution integral field spectroscopy has the potential to boost the detection rate of exoplanets, especially at small angular separations. Furthermore, it immediately provides…

Earth and Planetary Astrophysics · Physics 2023-07-19 Rico Landman , Ignas Snellen , Cristoph Keller , Mamadou N'Diaye , Fedde Fagginger-Auer , Célia Desgrange

Spatial resolution of most imaging devices is fundamentally restricted by diffraction. This limitation is manifested in the loss of high spatial frequency information contained in evanescent waves. As a result, conventional far-field optics…

Optics · Physics 2010-03-16 Leonid Alekseyev , Evgenii Narimanov , Jacob Khurgin

Holographic displays promise several benefits including high quality 3D imagery, accurate accommodation cues, and compact form-factors. However, holography relies on coherent illumination which can create undesirable speckle noise in the…

Graphics · Computer Science 2023-09-20 Grace Kuo , Florian Schiffers , Douglas Lanman , Oliver Cossairt , Nathan Matsuda

The phase diversity technique is a useful tool to measure and pre-compensate for quasi-static aberrations, in particular non-common path aberrations, in an adaptive optics corrected imaging system. In this paper, we propose and validate by…

Astrophysics · Physics 2009-11-13 L. M. Mugnier , J. -F. Sauvage , T. Fusco , A. Cornia , S. Dandy

Speckle Noise is the dominant source of error in high contrast imaging with adaptive optics system. We discuss the potential for wavefront sensing telemetry to calibrate speckle noise with sufficient precision and accuracy so that it can be…

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…

Astrophysics · Physics 2009-11-07 Henry G. Roe

Adaptive optics can focus light through opaque media by compensating the random phase delay acquired while crossing a scattering curtain. The technique is commonly exploited in many fields, including astrophysics, microscopy, biomedicine…

Optics · Physics 2015-06-24 Diego Di Battista , Giannis Zacharakis , Marco Leonetti

Recently introduced angular-memory-effect based techniques enable non-invasive imaging of objects hidden behind thin scattering layers. However, both the speckle-correlation and the bispectrum analysis are based on the statistical average…

Optics · Physics 2017-11-22 Tengfei Wu , Jonathan Dong , Xiaopeng Shao , Sylvain Gigan

Context. Direct imaging of exoplanets takes advantage of state-of-the-art adaptive optics (AO) systems, coronagraphy, and post-processing techniques. Coronagraphs attenuate starlight to mitigate the unfavorable flux ratio between an…

Instrumentation and Methods for Astrophysics · Physics 2022-09-21 Axel Potier , Johan Mazoyer , Zahed Wahhaj , Pierre Baudoz , Gael Chauvin , Raphael Galicher , Garreth Ruane

The integration of fine-scale multispectral imagery with deep learning models has revolutionized land use and land cover (LULC) classification. However, the atmospheric effects present in Top-of-Atmosphere sensor measured Digital Number…

Computer Vision and Pattern Recognition · Computer Science 2024-09-11 Soham Mukherjee , Yash Dixit , Naman Srivastava , Joel D Joy , Rohan Olikara , Koesha Sinha , Swarup E , Rakshit Ramesh

We discuss in some details a novel algorithm for performing partial-sky spherical harmonic transforms (SHT), building on the Fourier-sphere method of Reinecke et al (2023) handling efficiently high numbers of arbitrary locations on the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Julien Carron , Martin Reinecke

We summarize some of the compelling new scientific opportunities for understanding stars and stellar systems that can be enabled by sub-milliarcsec (sub-mas) angular resolution, UV-Optical spectral imaging observations, which can reveal the…

The scientific discoveries made by H.E.S.S. during its first year of operation encourage a reexamination of the open problems in high energy astrophysics and of the capabilities of the atmospheric Cherenkov technique, which could be…

Astrophysics · Physics 2007-05-23 V. Vassiliev , S. Fegan

We present an algorithm that uses the distribution of photon arrival times to distinguish speckles from incoherent sources, like planets and disks, in high contrast images. Using simulated data, we show that our approach can overcome the…

Instrumentation and Methods for Astrophysics · Physics 2019-10-09 Alex B. Walter , Clinton Bockstiegel , Timothy D. Brandt , Benjamin A. Mazin

Recent adaptive optics systems in astronomy achieve high-angular resolution. With the extreme stability of the images, detection at very low fluxes can be reached using a coronograph at the diffraction limit of the telescopes. This paper is…

Astrophysics · Physics 2007-05-23 Fabien Malbet

Herschel has revolutionized our ability to measure column densities (N$_{\rm H}$) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level…

Instrumentation and Methods for Astrophysics · Physics 2017-08-09 J. Abreu-Vicente , A. Stutz , Th. Henning , E. Keto , J. Ballesteros-Paredes , T. Robitaille

The neutral hydrogen 21cm line is potentially a very powerful probe of the observable universe, and a number of on-going experiments are trying to detect it at cosmological distances. However, the presence of strong foreground radiations…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Qizhi Huang , Fengquan Wu , Xuelei Chen

With the increasing number of directly imaged giant exoplanets the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models…

Earth and Planetary Astrophysics · Physics 2015-06-11 Veselin B. Kostov , Dániel Apai

Near-future astronomical survey experiments, such as LSST, possess system requirements of unprecedented fidelity that span photometry, astrometry and shape transfer. Some of these requirements flow directly to the array of science imaging…

We study the impact of the atmospheric differential chromatic refraction on the measurements and precision of relative astrometry. Specifically, we address the problem of measuring the separations of close pairs of binary stars with…

Astrophysics · Physics 2009-11-13 Krzysztof G. Hełminiak
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