English
Related papers

Related papers: Non-modulated pyramid wavefront sensor: Use in sen…

200 papers

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 performance of future observatories such as the Extremely Large Telescope is mainly limited by atmospheric turbulence and structural vibrations of the optical assembly. To further enhance the mitigation performance of adaptive optics,…

Instrumentation and Methods for Astrophysics · Physics 2025-09-17 Pascal Jaufmann , Aaron Buck , Marco Zaiser , Jörg-Uwe Pott , Oliver Sawodny

The future of space and ground based telescopes is intimately tied to technology and algorithm development surrounding wavefront sensing and control. Only with cutting edge developments and unusual ideas will we be able to build diffraction…

Instrumentation and Methods for Astrophysics · Physics 2022-04-04 J. Fowler , R. Deno Stelter

We introduce a simple but practical method to measure the optical transmission matrix (TM) of complex media. The optical TM of a complex medium is obtained by modulating the wavefront of a beam impinging on the complex medium and imaging…

Optics · Physics 2015-06-23 Jonghee Yoon , KyeoReh Lee , Jongchan Park , YongKeun Park

The next generation of adaptive optics (AO) systems will require tomographic reconstruction techniques to map the optical refractive index fluctuations, generated by the atmospheric turbulence, along the line of sight to the astronomical…

Instrumentation and Methods for Astrophysics · Physics 2014-01-07 H. W. Shepherd , J. Osborn , R. W. Wilson , T. Butterley , R. Avila , V. S. Dhillon , T. J. Morris

In this paper, we focus on constant-modulus waveform design for the dual use of radar target detection and cellular transmission. As the MIMO radar typically transmits orthogonal waveforms to search potential targets, we aim at jointly…

Signal Processing · Electrical Eng. & Systems 2019-04-15 Fan Liu , Christos Masouros , Hugh Griffiths

Atmospheric turbulence poses a challenge for the interpretation and visual perception of visual imagery due to its distortion effects. Model-based approaches have been used to address this, but such methods often suffer from artefacts…

Computer Vision and Pattern Recognition · Computer Science 2024-03-01 P. Hill , N. Anantrasirichai , A. Achim , D. R. Bull

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

Restoring images distorted by atmospheric turbulence is a ubiquitous problem in long-range imaging applications. While existing deep-learning-based methods have demonstrated promising results in specific testing conditions, they suffer from…

Image and Video Processing · Electrical Eng. & Systems 2023-12-12 Xingguang Zhang , Zhiyuan Mao , Nicholas Chimitt , Stanley H. Chan

Adaptive optics (AO) systems using tomographic estimation of three-dimensional structure of atmospheric turbulence requires vertical atmospheric turbulence profile, which describes turbulence strength as a function of altitude as a prior…

Instrumentation and Methods for Astrophysics · Physics 2021-04-21 Hajime Ogane , Masayuki Akiyama , Shin Oya , Yoshito Ono

Space-time modulation adds another powerful degree of freedom to the manipulation of classical wave systems. It opens the door for complex control of wave behavior beyond the reach of stationary systems, such as nonreciprocal wave transport…

Classical Physics · Physics 2019-11-06 Junfei Li , Xiaohui Zhu , Chen Shen , Xiuyuan Peng , Steven A. Cummer

In this paper, we design constant modulus probing waveforms with good correlation properties for collocated multi-input multi-output (MIMO) radar systems. The main content is as follows: first, we formulate the design problem as a fourth…

Signal Processing · Electrical Eng. & Systems 2019-09-04 Jiangtao Wang , Yongchao Wang

Cascaded H-bridge and modular multilevel converters (MMC) are on the rise with emerging applications in renewable energy generation, energy storage, and electric motor drives. However, their well-known advantages come at the price of…

Systems and Control · Electrical Eng. & Systems 2022-06-01 N. Tashakor , M. Kilictas , E. Bagheri , S. Goetz

Time series analysis finds wide applications in fields such as weather forecasting, anomaly detection, and behavior recognition. Previous methods attempted to model temporal variations directly using 1D time series. However, this has been…

Machine Learning · Computer Science 2024-11-08 Qiang Wu , Gechang Yao , Zhixi Feng , Shuyuan Yang

Extremely Large Telescopes have overwhelmingly opted for the Pyramid wavefront sensor (PyWFS) over the more widely used Shack-Hartmann WaveFront Sensor (SHWFS) to perform their Single Conjugate Adaptive Optics (SCAO) mode. The PyWFS, a…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Vincent Chambouleyron , Olivier Fauvarque , Pierre Janin-Potiron , Carlos Correia , Jean-François Sauvage , Noah Schwartz , Benoît Neichel , Thierry Fusco

The future upgrade of Keck II telescope's adaptive optics system will include a pyramid wavefront sensor working in the near-infrared (J and H band). It will benefit from the recently developed avalanche photodiode arrays, specifically the…

Instrumentation and Methods for Astrophysics · Physics 2023-01-18 Cédric Plantet , Guido Agapito , Christophe Giordano , Simone Esposito , Peter Wizinozich , Charlotte Bond

In this article, we compare a set of Wave Front Sensors (WFS) based on Fourier filtering technique. In particular, this study explores the "class of pyramidal WFS" defined as the 4 faces pyramid WFS, all its recent variations (6, 8 faces,…

Instrumentation and Methods for Astrophysics · Physics 2017-03-10 Olivier Fauvarque , Benoit Neichel , Thierry Fusco , Jean-François Sauvage , Orion Giraut

Separating the effects of waves and turbulence in oceanographic time series is an ongoing challenge because surface wave motion and turbulence fluctuations can occur at overlapping frequencies. Therefore, simple bandpass filters cannot…

Fluid Dynamics · Physics 2025-01-20 Julio Chávez-Dorado , Isabel Scherl , Michelle DiBenedetto

Temporal modulation unlocks possibilities to dynamically control and modify the response of electromagnetic systems. Employing explicit dependencies of circuit or surface parameters on time enables the engineering of systems with…

Systems and Control · Electrical Eng. & Systems 2023-03-01 Grigorii Ptitcyn , Mohammad Sajjad Mirmoosa , Silvi Hrabar , Sergey Tretyakov

Synthetic turbulence models are a useful tool that provide realistic representations of turbulence, necessary to test theoretical results, to serve as background fields in some numerical simulations, and to test analysis tools. Models of 1D…

Fluid Dynamics · Physics 2016-11-15 Francesco Malara , Francesca Di Mare , Giuseppina Nigro , Luca Sorriso-Valvo