English
Related papers

Related papers: Reaching micro-arcsecond astrometry with long base…

200 papers

Very long baseline interferometry (VLBI) astrometry is used to determine the three-dimensional position and proper motion of astronomical objects. A typical VLBI astrometric campaign generally includes around ten observations, making it…

High Energy Astrophysical Phenomena · Physics 2025-07-30 Ashish Kumar , Adam T. Deller , Pankaj Jain , Javier Moldón

This paper is devoted to a practical model for relativistic reduction of positional observations with an accuracy of 1 \muas which is expected to be attained in the future space astrometry missions. All relativistic effects which are caused…

Astrophysics · Physics 2007-05-23 Sergei A. Klioner

More than 450 exoplanets are known and this number increases nearly every day. Only a few constraints on their orbital parameters and physical characteristics can be determined, as most exoplanets are detected indirectly. Measuring the…

Instrumentation and Methods for Astrophysics · Physics 2010-05-28 Eva Meyer

Optical Coherence Tomography (OCT) was originally conceived as a volumetric imaging method. Quickly, OCT images went beyond structural data and started to provide functional information about an object enabling for example visualization of…

Multi-epoch radio-interferometric observations of young stellar objects can be used to measure their displacement over the celestial sphere with a level of precision that currently cannot be attained at any other wavelength. In particular,…

Astrophysics · Physics 2008-04-28 Laurent Loinard , Rosa M. Torres , Amy J. Mioduszewski , Luis F. Rodriguez

The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard the Swift observatory. The photometric calibration has been published, and this paper follows up with details on other aspects of the calibration including a…

Intensity interferometry removes the stringent requirements on mechanical precision and atmospheric corrections that plague all amplitude interferometry techniques at the cost of severely limited sensitivity. A new idea we recently…

Astrophysics · Physics 2009-11-11 Aviv Ofir , Erez N. Ribak

Length and g-factor are fundamental parameters that characterize optical cavities. We developed a technique to measure these parameters in-situ by determining the frequency spacing between the resonances of fundamental and spatial modes of…

Optics · Physics 2015-06-05 Alberto Stochino , Koji Arai , Rana X. Adhikari

We present a single-source dual atom interferometer and utilize it as a gradiometer for precise gravitational measurements. The macroscopic separation between interfering atomic wave packets (as large as 16 cm) reveals the interplay of…

The optical aberrations of a system can be described in terms of the wave aberrations, defined as the departure from the ideal spherical wavefront; or the ray aberrations, which are in turn the deviations from the paraxial ray intersection…

Optics · Physics 2016-01-20 John Restrepo , Pawel J. Stoerck , Ivo Ihrke

Adaptive optics (AO) instruments for the future extremely large telescopes (ELTs) are characterized by advanced optical systems with diffraction-limited optical quality. Low geometric distortion is also crucial for high accuracy astrometric…

Instrumentation and Methods for Astrophysics · Physics 2019-04-02 Mauro Patti , Matteo Lombini , Edoardo Maria Alberto Redaelli , Emiliano Diolaiti

Increasing the laser power is essential to improve the sensitivity of interferometric gravitational wave detectors. However, optomechanical parametric instabilities can set a limit to that power. It is of major importance to understand and…

Instrumentation and Methods for Astrophysics · Physics 2021-09-29 David Cohen , Annalisa Allocca , Gilles Bogaert , Paola Puppo , Thibaut Jacqmin , Virgo Collaboration

The diffraction contrast modalities accessible by X-ray grating interferometers are not imaged directly but have to be inferred from sine like signal variations occurring in a series of images acquired at varying relative positions of the…

Instrumentation and Detectors · Physics 2021-02-01 Jonas Dittmann , Andreas Balles , Simon Zabler

The optical interferometry has been widely used in various high precision applications. Usually, the minimum precision of an interferometry is limited by various technique noises in practice. To suppress such kind of noises, we propose a…

Optics · Physics 2018-06-20 Chen Fang , Jing-Zheng Huang , Guihua Zeng

Very Long Baseline Interferometric (VLBI) observations of quasar jets enable one to measure many theoretically expected effects. Estimating the significance of observational findings is complicated by the correlated noise in the image…

Instrumentation and Methods for Astrophysics · Physics 2018-10-22 I. N. Pashchenko

Geodetic Very Long Baseline Interferometry (VLBI) measures the group delay in the barycentric reference frame. As the Earth is orbiting around the Solar system barycentre with the velocity $V$ of 30 km/s, VLBI proves to be a handy tool to…

Instrumentation and Methods for Astrophysics · Physics 2018-10-10 Oleg Titov , Hana Krasna

Very long baseline interferometry (VLBI) provides the resolution needed to make precision measurements of a pulsar's parallax and proper motion. In making these measurements, the astronomer is faced with difficult calibration problems and a…

Astrophysics · Physics 2007-05-23 Walter Brisken

Context. High accuracy astrometric instruments like Gaia aiming at an accuracy of 1 microarcsecond cannot be considered as point-like observers in the framework of relativistic modelling of observable quantities. Aims. Special-relativistic…

Astrophysics · Physics 2007-05-23 G. Anglada-Escude , S. Klioner , M. Soffel , J. Torra

This paper focuses on the mission design for the Laser Astrometric Test Of Relativity (LATOR). This mission uses laser interferometry between two micro-spacecraft whose lines of sight pass close by the Sun to accurately measure deflection…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Slava G. Turyshev , Michael Shao , Kenneth L. Nordtvedt

We describe a novel pulsed magnetic gradiometer based on the optical interference of sidebands generated using two spatially separated alkali vapor cells. The sidebands are produced with high efficiency using parametric frequency conversion…

Atomic Physics · Physics 2021-11-25 Kaleb Campbell , Ying-Ju Wang , Igor Savukov , Peter Schwindt , Yuan-Yu Jau , Vishal Shah