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Related papers: On the comparison between MASS and G-SCIDAR techni…

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Measurements of a well-characterised standard sample can verify the performance of an instrument. Typically, small-angle neutron scattering instruments are used to investigate a wide range of samples and may often be used in a number of…

We present the largest database so far of atmospheric optical-turbulence profiles (197035 individual CN2(h)) for an astronomical site, the Roque de los Muchachos Observatory (La Palma, Spain). This C2 (h) database was obtained through…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 B. Garcia-Lorenzo , J. J. Fuensalida

We present a study of the small-scale structure of the interstellar medium in the Milky Way. We used HST STIS data to measure N(HI) in a pencil-beam toward 59 AGNs and compared the results with the values seen at 9 arcmin - 36 arcmin…

Astrophysics of Galaxies · Physics 2015-05-20 Bart P. Wakker , Felix J. Lockman , Jonathan M. Brown

One of the scientific goals of the Large Synoptic Survey Telescope (LSST) is to measure the evolution of dark energy by measuring subtle distortions of galaxy shapes due to weak gravitational lensing caused by the evolving dark matter…

Instrumentation and Methods for Astrophysics · Physics 2018-07-27 Claire-Alice Hébert , Bruce Macintosh , Patricia R. Burchat

The Laser Interferometer Space Antenna (LISA) is a proposed space mission for the detection of gravitational waves. It consists of three drag-free satellites flying in a triangular constellation. A gravitational reference sensor is used in…

Instrumentation and Methods for Astrophysics · Physics 2013-02-08 Andreas Zoellner , Eric Hultgren , Ke-Xun Sun

We present some statistics of turbulence monitoring at the Plateau de Calern (France), with the Generalised Differential Image Motion Monitor (GDIMM). This instrument allows to measure integrated parameters of the atmospheric turbulence,…

Instrumentation and Methods for Astrophysics · Physics 2018-11-20 Eric Aristidi , Yan Fantei-Caujolle , Julien Chabé , Catherine Renaud , Aziz Ziad , Malak Ben Rahhal

The optical turbulence conditions as measured between 2004 until end of 2008 above Cerro Tololo, their seasonal as well as nocturnal behavior are presented. A comparison with the MASS-DIMM system of the Thirty Meter Telescope site testing…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 S. G. Els , M. Schoeck , E. Bustos , J. Seguel , J. Vasquez , D. Walker , R. Riddle , W. Skidmore , T. Travouillon , K. Vogiatzis

Observations with ground-based telescopes are affected by differential atmospheric dispersion due to the wavelength-dependent index of refraction of the atmosphere. The usage of an Atmospheric Dispersion Corrector (ADC) is fundamental to…

Instrumentation and Methods for Astrophysics · Physics 2020-10-14 B. Wehbe , A. Cabral , G. Avila

Intensity scintillations of cosmic radio sources are used to study astrophysical plasmas like the ionosphere, the solar wind, and the interstellar medium. Normally these observations are relatively narrow band. With Low Frequency Array…

The free-space optical channel has the potential to facilitate inexpensive, wireless communication with fiber-like bandwidth under short deployment timelines. However, atmospheric effects can significantly degrade the reliability of a…

Information Theory · Computer Science 2008-04-02 Nick Letzepis , Albert Guillen i Fabregas

This study explores the use of historical data from Global Navigation Satellite System (GNSS) scintillation monitoring receivers to predict the severity of amplitude scintillation, a phenomenon where electron density irregularities in the…

Signal Processing · Electrical Eng. & Systems 2024-09-04 Sultan Halawa , Maryam Alansaari , Maryam Sharif , Amel Alhammadi , Ilias Fernini

Atmospheric turbulence characterization is crucial for technologies like free-space optical communications. Existing methods using a spatially-integrated one-dimensional (1D) orbital angular momentum (OAM) spectrum, P(m), obscure the…

Optics · Physics 2025-09-09 Wenjie Jiang , Mingjian Cheng , Lixin Guo , Andrew Forbes

We numerically examine the spatial evolution of the structure of coherent and partially coherent laser beams, including the optical vortices, propagating in turbulent atmospheres. The influence of beam fragmentation and wandering relative…

Optics · Physics 2015-05-19 G. P. Berman , V. N. Gorshkov , S. V. Torous

The image quality from Ground-Layer Adaptive Optics (GLAO) can be gradually increased with decreased contiguous field of view. This trade-off is dependent on the vertical profile of the optical turbulence (Cn2 profiles). It is known that…

Instrumentation and Methods for Astrophysics · Physics 2009-12-23 J. Stoesz , E. Masciadri , F. Lascaux , S. Hagelin

Plasma scattering measurement is effective technique to observe low frequency density fluctuations excited in plasma. The spatial and wave number resolutions and the S/N ratio of measurement depend on the wavelength range, the size and the…

Real-time seeing and outer scale estimation at the location of the focus of a telescope is fundamental for the adaptive optics systems dimensioning and performance prediction, as well as for the operational aspects of instruments. This…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Patrice Martinez

Context: By providing information about the location of scattering material along the line of sight (LoS) to pulsars, scintillation arcs are a powerful tool for exploring the distribution of ionized material in the interstellar medium.…

The power spectrum of water optical turbulence is shown to vary with its average temperature $\left\langle T \right\rangle$ and average salinity concentration $\left\langle S \right\rangle$, as well as with light wavelength $\lambda$. This…

Atmospheric and Oceanic Physics · Physics 2020-10-28 Jinren Yao , Mohammed Elamassie , Olga Korotkova

We model long-term variations in the scintillation of binary pulsar PSR J1603$-$7202, observed by the 64 m Parkes radio telescope (Murriyang) between 2004 and 2016. We find that the time variation in the scintillation arc curvature is…

High Energy Astrophysical Phenomena · Physics 2022-07-06 Kris Walker , Daniel J. Reardon , Eric Thrane , Rory Smith

(Abridged) Atmospheric dispersion and field differential refraction impose severe constraints on widefield MOS observations. Flux reduction and spectral distortions must be minimised by a careful planning of the observations -- which is…

Instrumentation and Methods for Astrophysics · Physics 2014-06-04 Rubén Sánchez-Janssen , Steffen Mieske , Fernando Selman , Paul Bristow , Peter Hammersley , Michael Hilker , Marina Rejkuba , Burkhard Wolff
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