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We introduce fast millimeter-wave base station (BS) and its antenna sector selection for user equipment based on its location. Using a conditional random field inference model with specially designed parameters, which are robust to change…

Networking and Internet Architecture · Computer Science 2018-03-06 Sai Qian Zhang , H. T. Kung , Youngjune Gwon

Interferometry is a powerful technique for making sensitive, high-fidelity images of the sky, but is limited in its ability to measure extended or diffuse emission. Better images of extended astronomical objects can be obtained by…

Instrumentation and Methods for Astrophysics · Physics 2020-06-12 Brian S. Mason

Classically, optical and near-infrared interferometry have relied on closure phase techniques to produce images. Such techniques allow us to achieve modest dynamic ranges. In order to test the feasibility of next generation optical…

Starlight suppression techniques for High-Contrast Imaging (HCI) are crucial to achieving the demanding contrast ratios and inner working angles required for detecting and characterizing exoplanets with a wide range of masses and…

The Laser Interferometer Space Antenna (LISA) is a future space-based interferometric gravitational-wave detector consisting of three spacecraft in a triangular configuration. The interferometric measurements of path length changes between…

We discuss the ongoing development of single-mode fiber Fabry-Perot (FFP) Interferometers as precise astro-photonic calibration sources for high precision radial velocity (RV) spectrographs. FFPs are simple, inexpensive, monolithic units…

We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the…

Quantum Physics · Physics 2012-09-03 Daniel Gottesman , Thomas Jennewein , Sarah Croke

Betelgeuse has gone through a sudden shift in its brightness and dimmed mysteriously. This is likely caused by a hot blob of plasma ejected from Betelgeuse and then cooled to obscuring dust. If true, it is a remarkable opportunity to…

We explore the sensitivity and completeness of long baseline interferometric observations for detecting unknown, faint companions around bright unresolved stars. We derive a linear expression for the closure phase signature of a faint…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Jean-Baptiste Le Bouquin , Olivier Absil

High precision astrometric Space Very Long Baseline Interferometry (S-VLBI) at the low end of the conventional frequency range, i.e. 20cm, is a requirement for a number of high priority science goals. These are headlined by obtaining…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 R. Dodson , M. Rioja , Y. Asaki , H. Imai , X. -Y. Hong , Z. Shen

The 2nd generation VLTI instrument GRAVITY is a two-field infrared interferometer operating in the K band between 1.97 and 2.43 $\mu$m with either the four 8 m or the four 1.8 m telescopes of the Very Large Telescope (VLT). Beams collected…

Optical imaging with microarcsecond resolution will reveal details across and outside stellar surfaces but requires kilometer-scale interferometers, challenging to realize either on the ground or in space. Intensity interferometry,…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 Dainis Dravins

Astrometry at centimeter wavelengths using Very Long Baseline Interferometry is approaching accuracies of ~1 uas for the angle between a target and a calibrator source separated by <1 degree on the sky. The BeSSeL Survey and the Japanese…

Instrumentation and Methods for Astrophysics · Physics 2023-01-13 Mark J. Reid

Very long baseline interferometry (VLBI) makes it possible to recover images of astronomical sources with extremely high angular resolution. Most recently, the Event Horizon Telescope (EHT) has extended VLBI to short millimeter wavelengths…

Instrumentation and Methods for Astrophysics · Physics 2018-02-05 Katherine L. Bouman , Michael D. Johnson , Adrian V. Dalca , Andrew A. Chael , Freek Roelofs , Sheperd S. Doeleman , William T. Freeman

Detecting the angles and orbits of remote targets precisely has been playing crucial roles in astrophysical research. Due to the resolution limitations imposed by the Airy disk in a single telescope, optical interferometric schemes with at…

Instrumentation and Methods for Astrophysics · Physics 2025-02-12 Yi-Xin Shen , Zhou-Kai Cao , Jian Leng , Xiang-Bin Wang

Baseline calibration of a stellar interferometer is a prerequisite to data reduction of astrometric operations. This technique of astrometry is triangulation of star positions. Since angles are deduced from the baseline and delay side of…

Instrumentation and Methods for Astrophysics · Physics 2009-06-16 Richard J. Mathar

The Fringe Sensor Unit (FSU) is the central element of the Phase Referenced Imaging and Micro-arcsecond Astrometry (PRIMA) dual-feed facility and provides fringe sensing for all observation modes, comprising off-axis fringe tracking, phase…

Instrumentation and Methods for Astrophysics · Physics 2009-12-08 Johannes Sahlmann , Serge Menardi , Roberto Abuter , Matteo Accardo , Sergio Mottini , Francoise Delplancke

The Low Frequency Instrument (LFI) is one of the two instruments onboard the ESA PLANCK satellite foreseen to be launched in 2007. The LFI will image the Cosmic Microwave Background (CMB) anisotropies and the polarization in four different…

The Wide-Field Imaging Interferometry Testbed (WIIT) will provide valuable information for the development of space-based interferometers. This laboratory instrument operates at optical wavelengths and provides the ability to test…

A long-held astronomical vision is to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, show their evolution over time, and reveal…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Dainis Dravins , Tiphaine Lagadec
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