English
Related papers

Related papers: Real-time correlation reference update for astrono…

200 papers

The precise knowledge of the positions of space debris objects and in particular of defunct satellites is fundamental for satellite operations. Several studies showed that it is possible to improve the accuracy of the orbit determination…

Earth and Planetary Astrophysics · Physics 2019-03-04 E. Cordelli , P. Schlatter , P. Lauber , T. Schildknecht

Using five independent analytic and Monte Carlo simulation codes, we have studied the performance of wide field ground layer adaptive optics (GLAO), which can use a single, relatively low order deformable mirror to correct the wavefront…

We present the details of predicting atmospheric turbulence by mining Zernike moment data obtained from simulations as well as experiments. Temporally correlated optical wave-fronts were simulated such that they followed Kolmogorov phase…

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

We investigate the limits of ground-based astrometry with adaptive optics using the core of the Galactic globular cluster M5. Adaptive optics systems provide near diffraction-limit imaging with the world's largest telescopes. The…

Astrophysics · Physics 2009-11-13 P. B. Cameron , M. C. Britton , S. R. Kulkarni

Context. Modern space telescopes are currently providing high-precision light curves for a large fraction of the sky, such that many new variable stars are being discovered. However, some stars have periodic variability with periods of…

Solar and Stellar Astrophysics · Physics 2019-08-28 Dominic M. Bowman , Daniel L. Holdsworth

In this study, we compared results of determination of the orientation angles between celestial reference frames realized by radio source position catalogues using three methods of accounting for correlation information: using the position…

Instrumentation and Methods for Astrophysics · Physics 2019-07-30 Yulia Sokolova , Zinovy Malkin

Aberrations limit optical systems in many situations, for example when imaging in biological tissue. Machine learning offers novel ways to improve imaging under such conditions by learning inverse models of aberrations. Learning requires…

Optics · Physics 2021-04-30 Ivan Vishniakou , Johannes D. Seelig

Adaptive optic (AO) systems delivering high levels of wavefront correction are now common at observatories. One of the main limitations to image quality after wavefront correction comes from atmospheric refraction. An Atmospheric dispersion…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Prashant Pathak , Olivier Guyon , Nemanja Jovanovic , Julien Lozi , Frantz Martinache , Yosuke Minowa , Tomoyuki Kudo , Takayuki Kotani , Hideki Takami

Observational tests of ground layer wavefront recovery have been made in open loop using a constellation of four natural guide stars at the 1.55 m Kuiper telescope in Arizona. Such tests explore the effectiveness of wide-field seeing…

Astrophysics · Physics 2011-02-11 Christoph Baranec , Michael Lloyd-Hart , N. Mark Milton

Differentiating between an exoplanet signal and residual speckle noise is a key challenge in high-contrast imaging. Speckles are due to a combination of fast, slow and static wavefront aberrations introduced by atmospheric turbulence and…

The Earth observation satellites have been monitoring the earth's surface for a long time, and the images taken by the satellites contain large amounts of valuable data. However, it is extremely hard work to manually analyze such huge data.…

Computer Vision and Pattern Recognition · Computer Science 2017-07-31 Kazuki Uehara , Hidenori Sakanashi , Hirokazu Nosato , Masahiro Murakawa , Hiroki Miyamoto , Ryosuke Nakamura

In this paper a proposal is made of an adaptive coupling function for achieving synchronization between two lasers subject to optical feedback. Such a control scheme requires knowledge of the systems' parameters. For the first time we…

Chaotic Dynamics · Physics 2007-05-23 E. M. Shahverdiev , R. A. Nuriev , R. H. Hashimov , K. A. Shore

Large telescope's adaptive optics (AO) system requires one or several bright artificial laser guide stars to improve its sky coverage. The recent advent of high power sodium laser is perfect for such application. However, besides the output…

Instrumentation and Methods for Astrophysics · Physics 2016-05-23 Feng Lu , Zhi-Xia Shen , Suijian Xue , Yang-Peng Li , Kai Jin , Angel Otarola , Yong Bo , Jun-Wei Zuo , Qi Bian , Kai Wei , Jing-Yao Hu

Optical interferometry has been successful at achieving milliarcsecond resolution on bright stars. Imaging performance can improve greatly by increasing the number of baselines, which has motivated proposals to build large (~ 100 m) optical…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Paul D. Nuñez , Antoine Labeyrie , Pierre Riaud

The method of wavefront shaping to control optical properties of opaque media is a promising technique for authentication applications. One of the main challenges of this technique is the sensitivity of the wavefront-sample coupling to…

Optics · Physics 2015-08-24 Benjamin R. Anderson , Ray Gunawidjaja , Hergen Eilers

The optimal performance of adaptive optics systems can only be maintained if the wavefront reference is bright and compact. Experience has shown that both of these important criteria are remarkably difficult to achieve with laser guide…

Astrophysics · Physics 2007-05-23 S. Rabien , T. Ott , W. Hackenberg , A. Eckart , R. Davies , M. Kasper , A. Quirrenbach

Extreme adaptive optics systems are now in operation across the globe. These systems, capable of high order wavefront correction, deliver Strehl ratios of 90% in the near-infrared. Originally intended for the direct imaging of exoplanets,…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 Nemanja Jovanovic , Christian Schwab , Nick Cvetojevic , Olivier Guyon , Frantz Martinache

Shack-Hartmann wavefront sensors (SHWS) are generally used to measure the wavefront curvature of light beams. Measurement accuracy and the sensitivity of these sensors are important factors for better wavefront sensing. In this study, we…

Optics · Physics 2021-10-04 Nitin Dubey , Ravi Kumar , Joseph Rosen

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

Microscopy and optical imaging are drastically limited by the inhomogeneities encountered by the light while propagating from the object of interest to the detection system. In this context, adaptive optics and wavefront manipulation are…

Optics · Physics 2017-01-23 Diego Di Battista