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The displacement of star images by atmospheric refraction observed by an Earth-bound telescope is dominated by a familiar term proportional to the product of the tangent of the zenith angle by the refractivity at the ground. The manuscript…

Instrumentation and Methods for Astrophysics · Physics 2015-03-02 Richard J. Mathar

Atmospheric refraction modifies the apparent position of objects in the sky. We computed the lateral translation that is to be considered for short-range applications, such as wavefront sensing and meteor trajectories. We aim to calculate…

Instrumentation and Methods for Astrophysics · Physics 2022-03-08 Hanae Labriji , Olivier Herscovici-Schiller , Frédéric Cassaing

The Profiler of Moon Limb is a recent instrument dedicated to the monitoring of optical turbulence profile of the atmosphere. Fluctuations of the Moon or the Sun limb allow to evaluate the index refraction structure constant C_n^2(h) and…

Instrumentation and Methods for Astrophysics · Physics 2020-02-13 Eric Aristidi , Aziz Ziad , Yan Fantéï-Caujolle , Julien Chabé , Christophe Giordano , Catherine Renaud , Henri Lantéri

Transmission spectra contain a wealth of information about the atmospheres of transiting exoplanets. However, large thermal and chemical gradients along the line of sight can lead to biased inferences in atmospheric retrievals. In order to…

Earth and Planetary Astrophysics · Physics 2021-12-16 Joost P. Wardenier , Vivien Parmentier , Elspeth K. H. Lee

Context. Limb darkening is an important tool for understanding stellar atmospheres, but most observations measuring limb darkening assume various parameterizations that yield no significant information about the structure of stellar…

Solar and Stellar Astrophysics · Physics 2015-06-05 Hilding R. Neilson , John B. Lester

This report models the refractive index above a telescope site by an atmosphere with exponential decay of the refractive index (susceptibility) as a function of altitude. The air is represented as a spherical hull around the surface. We…

Instrumentation and Methods for Astrophysics · Physics 2020-08-18 Richard J. Mathar

We explore the sensitivity of limb darkening coefficients computed from stellar atmosphere models to different least-squares fitting methods. We demonstrate that conventional methods are strongly biased to fitting the stellar limb. Our…

Astrophysics · Physics 2008-11-26 David Heyrovsky

This paper quantifies an error source that limits the accuracy of lidar scan matching, particularly for voxel-based methods. Lidar scan matching, which is used in dead reckoning (also known as lidar odometry) and mapping, computes the…

Robotics · Computer Science 2024-01-25 Jason Rife , Matthew McDermott

Spectra of astronomical targets acquired from ground-based instruments are affected by the atmospheric transmission. The authors and their institutes are developing a web-based service, TAPAS (Transmissions of the AtmosPhere for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 J. L. Bertaux , R. Lallement , S. Ferron , C. Boone , R. Bodichon

Motivated by the recognition that variation in the optical transmission of the atmosphere is probably the main limitation to the precision of ground-based CCD measurements of celestial fluxes, we review the physical processes that attenuate…

The distinction between point and line resolution in transmission electron microscopy (TEM) arises because an ability to image sub-0.2 nm fringes is a necessary, but not a sufficient, condition for imaging individual atoms. In scanned tip…

Instrumentation and Detectors · Physics 2007-05-23 P. Fraundorf , J. Tentschert

(Abridged) Context. Stellar limb darkening, I({\mu} = cos{\theta}), is an important constraint for microlensing, eclipsing binary, planetary transit, and interferometric observations, but is generally treated as a parameterized curve, such…

Solar and Stellar Astrophysics · Physics 2015-05-28 Hilding R. Neilson , John B. Lester

Atmospheric optical turbulence seriously limits the performance of high angular resolution instruments. An 8-night campaign of measurements was carried out at the LAMOST site in 2011, to characterize the optical turbulence. Two instruments…

Instrumentation and Methods for Astrophysics · Physics 2015-05-21 L. -Y. Liu , C. Giordano , Y. -Q. Yao , J. Vernin , M. Chadid , H. -S. Wang , J. Yin , Y. -P. Wang

Nowadays, static, mobile, terrestrial, and airborne laser scanning technologies have become familiar data sources for engineering work, especially in the area of land surveying. The diversity of Light Detection and Ranging (LiDAR) data…

Methodology · Statistics 2023-12-07 Fayez Tarsha Kurdi , Paul Reed , Zahra Gharineiat , Mohammad Awrangjeb

We address a data augmentation problem for LiDAR. Given a LiDAR scan of a scene from some position, how can one simulate new scans of that scene from different, secondary positions? The method defines criteria for selecting valid secondary…

Computer Vision and Pattern Recognition · Computer Science 2021-11-23 Xavier Morin-Duchesne , Michael S Langer

Adaptive optics will almost completely remove the effects of atmospheric turbulence at 10 microns on the Extremely Large Telescope (ELT) generation of telescopes. In this paper, we observationally confirm that the next most important…

Instrumentation and Methods for Astrophysics · Physics 2010-03-26 Andrew Skemer , Philip Hinz , William Hoffmann , Laird Close , Sarah Kendrew , Richard Mathar , Remko Stuik , Thomas Greene , Charles Woodward , Michael Kelley

Looming, traditionally defined as the relative expansion of objects in the observer's retina, is a fundamental visual cue for perception of threat and can be used to accomplish collision free navigation. The measurement of the looming cue…

Computer Vision and Pattern Recognition · Computer Science 2022-03-16 Juan D. Yepes , Daniel Raviv

This paper presents the exact error analysis of point positioning equation used for airborne three-dimensional(3D) imaging sensor. With differential calculus and principles of precision analysis a mathematics formula on the point position…

Optics · Physics 2015-03-13 Yuesong Jiang , Xiaoxia Liu , Ruiqiang Chen , Yanling Wang

This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different characterizations of a given model atmosphere can give quite different numerical results…

Solar and Stellar Astrophysics · Physics 2015-05-28 Ian D. Howarth

One of the biggest problems we can encounter while dealing with the limb-darkening coefficients for stellar atmospheric models with spherical symmetry is the difficulty of adjusting both the limb and the central parts simultaneously. In…

Solar and Stellar Astrophysics · Physics 2018-10-10 Antonio Claret
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