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Related papers: New concepts for calibrating non-common path aberr…

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In an effort to transcend the limitations of differential imaging of exoplanets in the era of extremely large telescopes (ELTs), the first paper in this series established a rigorous, fully polarimetric framework for determining the science…

Instrumentation and Methods for Astrophysics · Physics 2016-02-18 Richard A. Frazin

The Evanescent Wave Coronagraph (EvWaCo) is an achromatic coronagraph mask with adjustable size over the spectral domain [600nm, 900nm] that will be installed at the Thai National Observatory. We present in this work the development of a…

Compressive focal plane arrays (FPA) enable cost-effective high-resolution (HR) imaging by acquisition of several multiplexed measurements on a low-resolution (LR) sensor. Multiplexed encoding of the visual scene is typically performed via…

Image and Video Processing · Electrical Eng. & Systems 2023-09-21 Alper Güngör , M. Umut Bahceci , Yasin Ergen , Ahmet Sözak , O. Oner Ekiz , Tolga Yelboga , Tolga Çukur

The CHARA Array is the longest baseline optical interferometer in the world. Operated with natural seeing, it has delivered landmark sub-milliarcsecond results in the areas of stellar imaging, binaries, and stellar diameters. However, to…

The correction of quasi-static wavefront errors within a coronagraphic optical system will be a key challenge to overcome in order to directly image exoplanets in reflected light. These quasi-static errors are caused by mid to high-order…

Instrumentation and Methods for Astrophysics · Physics 2024-06-28 Kian Milani , Ewan Douglas , Leonid Pogorelyuk , Christopher Mendillo , Kerri Cahoy , Nicholas Belsten , Brandon Eickert , Shanti Rao

Accurate astrometry and photometry of saturated and coronagraphic point spread functions (PSFs) are fundamental to both ground- and space-based high contrast imaging projects. For ground-based adaptive optics imaging, differential…

Astrophysics · Physics 2008-11-26 C. Marois , D. Lafreniere , B. Macintosh , R. Doyon

We compare coronagraph concepts and investigate their behavior and suitability for planet finder projects with Extremely Large Telescopes (ELTs, 30-42 meters class telescopes). For this task, we analyze the impact of major error sources…

Astrophysics · Physics 2009-11-13 P. Martinez , A. Boccaletti , M. Kasper , C. Cavarroc , N. Yaitskova , T. Fusco , C. Verinaud

Performances of an adaptive optics (AO) system are directly linked with the quality of its alignment. During the instrument calibration, having open loop fast tools with a large capture range are necessary to quickly assess the system…

In fields such as ecology, microbiology, and genomics, non-Euclidean distances are widely applied to describe pairwise dissimilarity between samples. Given these pairwise distances, principal coordinates analysis (PCoA) is commonly used to…

Quantitative Methods · Quantitative Biology 2020-03-24 Yushu Shi , Liangliang Zhang , Kim-Anh Do , Christine Peterson , Robert Jenq

The capability of the adaptive optics to correct for the segmentation error is analyzed in terms of the residual wavefront RMS and the power spectral density of the phase. The analytical model and the end-to-end simulation give…

Astrophysics · Physics 2009-11-11 Natalia Yaitskova , Christophe Verinaud

The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental non-common path errors (NCPEs). Rapid development of efficient…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 Michael J. Wilby , Christoph U. Keller , Frans Snik , Visa Korkiakoski , Alexander G. M. Pietrow

Here the role and influence of aberrations in optical imaging systems employing partially coherent complex scalar fields is studied. Imaging systems require aberrations to yield contrast in the output image. For linear shift-invariant…

Optics · Physics 2015-06-30 Mario A. Beltran , Marcus J. Kitchen , T. Petersen , David M. Paganin

Direct imaging of exo-Earths and search for life is one of the most exciting and challenging objectives for future space observatories. Segmented apertures in space will be required to reach the needed large diameters beyond the…

Most current astronomical adaptive optics (AO) systems rely on the availability of a bright star to measure the distortion of the incoming wavefront. Replacing the guide star with an artificial laser beacon alleviates this dependency on…

Astrophysics · Physics 2009-11-11 E. Steinbring , S. M. Faber , B. A. Macintosh , D. Gavel , E. L. Gates

The Back-Projection Algorithm (BPA) is a time domain matched filtering technique to form synthetic aperture radar (SAR) images. To produce high quality BPA images, precise navigation data for the radar platform must be known. Any error in…

Signal Processing · Electrical Eng. & Systems 2024-10-30 Colton Lindstrom , Randall Christensen , Jacob Gunther

Laser guide stars with adaptive optics allow astronomical image correction in the absence of a natural guide star. Single guide star systems with a star created in the earth's sodium layer can be used to correct the wavefront in the near…

Astrophysics · Physics 2009-11-11 S. Rabien , F. Eisenhauer , R. Genzel , R. I. Davies , T. Ott

In ultrasound imaging, propagation of an acoustic wavefront through heterogeneous media causes phase aberrations that degrade the coherence of the reflected wavefront, leading to reduced image resolution and contrast. Adaptive imaging…

We develop a Coherent Perfect Absorption (CPA) protocol for cases where scale invariance is violated due to the presence of nonlinear mechanisms. We demonstrate, using a microwave setting that lacks geometrical symmetries, that the…

Current and future high contrast imaging instruments aim to detect exoplanets at closer orbital separations, lower masses, and/or older ages than their predecessors. However, continually evolving speckles in the coronagraphic science image…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

Direct imaging of Earth-like planets from space requires dedicated observatories, combining large segmented apertures with instruments and techniques such as coronagraphs, wavefront sensors, and wavefront control in order to reach the high…