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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

We propose design of a low-cost passive scintillometer that measures the strength of optical turbulence by analyzing scintillation in the image of a straight edge between the two areas of uniform, but distinct brightness. Two theoretical…

Optics · Physics 2021-11-24 Mikhail Charnotskii

Starlight corrupted by atmospheric turbulence cannot couple efficiently into astronomical instruments based on integrated optics as they require light of high spatial coherence to couple into their single-mode waveguides. Low-order adaptive…

Instrumentation and Methods for Astrophysics · Physics 2021-03-26 Momen Diab , Aline N. Dinkelaker , John Davenport , Kalaga Madhav , Martin M. Roth

Nullifying the servo bandwidth errors improves the strehl ratio by a substantial quantity in adaptive optics systems. An effective method for predicting atmospheric turbulence to reduce servo bandwidth errors in real time closed loop…

Instrumentation and Methods for Astrophysics · Physics 2011-09-14 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

Astrometric detection involves a precise measurement of stellar positions, and is widely regarded as the leading concept presently ready to find earth-mass planets in temperate orbits around nearby sun-like stars. The TOLIMAN space…

This project outlines the complete development of a variable star classification algorithm methodology. With the advent of Big-Data in astronomy, professional astronomers are left with the problem of how to manage large amounts of data, and…

Instrumentation and Methods for Astrophysics · Physics 2020-09-01 Kyle Burton Johnston

Adaptive optics (AO) systems allow a telescope to reach its diffraction limit at near infrared wavelengths. But to achieve this, a bright natural guide star (NGS) is needed for the wavefront sensing, severely limiting the fraction of the…

The performance of an adaptive optics (AO) system on a 100m diameter ground based telescope working in the visible range of the spectrum is computed using an analytical approach. The target Strehl ratio of 60% is achieved at 0.5um with a…

Astrophysics · Physics 2009-10-31 M. Le Louarn , N. Hubin , M. Sarazin , A. Tokovinin

Fast variability of optical objects is an interesting though poorly explored subject in modern astronomy. Real-time data processing and identification of transient celestial events in the images is very important for such study as it allows…

We analyze hydrodynamic simulations of turbulent, star-forming molecular clouds that are post-processed with the photo-dissociation region astrochemistry code 3D-PDR. We investigate the sensitivity of 15 commonly applied turbulence…

Astrophysics of Galaxies · Physics 2018-07-11 Ryan D. Boyden , Stella S. R. Offner , Eric W. Koch , Erik W. Rosolowsky

Atmospheric Turbulence (AT) correction is a challenging restoration task as it consists of two distortions: geometric distortion and spatially variant blur. Diffusion models have shown impressive accomplishments in photo-realistic image…

Computer Vision and Pattern Recognition · Computer Science 2023-07-28 Xijun Wang , Santiago López-Tapia , Aggelos K. Katsaggelos

This study introduces OTCliM (Optical Turbulence Climatology using Machine learning), a novel approach for deriving comprehensive climatologies of atmospheric optical turbulence strength ($C_n^2$) using gradient boosting machines. OTCliM…

Atmospheric and Oceanic Physics · Physics 2025-06-02 Maximilian Pierzyna , Sukanta Basu , Rudolf Saathof

We consider the inverse problem of fitting atmospheric dispersion parameters based on time-resolved back-scattered differential absorption Lidar (DIAL) measurements. The obvious advantage of light-based remote sensing modalities is their…

Analysis of PDEs · Mathematics 2023-08-01 Robert Lung , Nick Polydorides

Selene is the attempt to implement a new scheme for high-intensity specular reflectometry. Instead of a highly collimated beam one uses a convergent beam covering a large angular range. The angular resolution is then performed by a…

Instrumentation and Detectors · Physics 2011-02-15 J. Stahn , U. Filges , T. Panzner

We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is…

Instrumentation and Methods for Astrophysics · Physics 2016-11-26 Christoph U. Keller , Visa Korkiakoski , Niek Doelman , Rufus Fraanje , Raluca Andrei , Michel Verhaegen

Direct imaging and spectral characterization of exoplanets using extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes and space observatories. However, quasi-static wavefront errors will limit the…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Benjamin L. Gerard , Christian Marois , Raphaël Galicher

Context. The GRAVITY instrument on the ESO VLTI is setting a new mark in the landscape of optical interferometers. Long exposures are possible for the first time in this wavelength domain, delivering a dramatic improvement for astrophysics.…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Guy Perrin , Julien Woillez

Scene Text Image Super-Resolution (STISR) aims to restore high-resolution details in low-resolution text images, which is crucial for both human readability and machine recognition. Existing methods, however, often depend on external…

Computer Vision and Pattern Recognition · Computer Science 2026-03-17 Axi Niu , Kang Zhang , Qingsen Yan , Hao Jin , Jinqiu Sun , Yanning Zhang

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…

Context: Current instrument developments at the largest telescopes worldwide have provisions for Multi-Conjugated Adaptive Optics (MCAO) modules. The large field of view and more uniform correction provided by these systems is not only…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Eva Meyer , Martin Kuerster , Carmelo Arcidiacono , Roberto Ragazzoni , Hans-Walter Rix
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