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Related papers: Atmospheric pressure loading for routine data anal…

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This work devotes to investigations of solar corona and solar wind plasma by the method of radio probing with using of very long baseline interferometry (VLBI). We performed the theoretical calculation of power spectrum of interferometric…

Electricity is difficult to store, except at prohibitive cost, and therefore the balance between generation and load must be maintained at all times. Electricity is traditionally managed by anticipating demand and intermittent production…

Machine Learning · Computer Science 2024-09-26 Julie Keisler , Margaux Bregere

We present the results of PSR$\pi$, a large astrometric project targeting radio pulsars using the Very Long Baseline Array (VLBA). From our astrometric database of 60 pulsars, we have obtained parallax-based distance measurements for all…

Instrumentation and Methods for Astrophysics · Physics 2019-05-07 A. T. Deller , W. M. Goss , W. F. Brisken , S. Chatterjee , J. M. Cordes , G. H. Janssen , Y. Y. Kovalev , T. J. W. Lazio , L. Petrov , B. W. Stappers , A. Lyne

Very-long-baseline interferometry (VLBI) at frequencies above 230 GHz with Earth-diameter baselines gives spatial resolution finer than the ${\sim}50 \mu$as "shadow" of the supermassive black hole at the Galactic Center, Sagittarius A* (Sgr…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Daniel C. M. Palumbo , Sheperd S. Doeleman , Michael D. Johnson , Katherine L. Bouman , Andrew A. Chael

This paper presents the fourth extension to the Very Long Baseline Array (VLBA) Calibrator Survey, containing 258 new sources not previously observed with very long baseline interferometry (VLBI). This survey, based on three 24 hour VLBA…

Astrophysics · Physics 2008-11-26 L. Petrov , Y. Y. Kovalev , E. Fomalont , D. Gordon

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

Inspired by biological swimming and flying with distributed sensing, we propose a data-driven approach for load estimation that relies on complex networks. We exploit sparse, real-time pressure inputs, combined with pre-trained transition…

Fluid Dynamics · Physics 2022-02-16 Giovanni Iacobello , Frieder Kaiser , David E. Rival

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

The observation and imaging of hundreds or thousands of radio sources with the technique of very long baseline interferometry (VLBI) is a computationally intensive task. However, these surveys allow us to conduct statistical investigations…

Astrophysics of Galaxies · Physics 2017-06-28 Kristóf Rozgonyi , Sándor Frey

As the peak of the solar cycle approaches in 2025 and the ability of a single geomagnetic storm to significantly alter the orbit of Resident Space Objects (RSOs), techniques for atmospheric density forecasting are vital for space…

Atmospheric and Oceanic Physics · Physics 2023-10-27 Julia Briden , Peng Mun Siew , Victor Rodriguez-Fernandez , Richard Linares

Published analyses of very long baseline interferometry (VLBI) data for the sources included in the third International Celestial Reference Frame (ICRF3) catalog have revealed object-specific, excess astrometric variability and…

Astrophysics of Galaxies · Physics 2024-11-27 Valeri V. Makarov , Phil Cigan , David Gordon , Megan C. Johnson , Christopher DiLullo , Sébastien Lambert

The 16th magnitude quasar 3C 345 (redshift z=0.5928) shows structural and emission variability on parsec scales around a compact unresolved radio core. For the last three decades it has been closely monitored with very long baseline…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-31 Frank K. Schinzel , Andrei P. Lobanov , J. Anton Zensus

Atmospheric structure, represented by backscatter coefficients (BC) recovered from satellite LiDAR attenuated backscatter (ATB), provides a volumetric view of clouds, aerosols, and molecules, playing a critical role in human activities,…

Computer Vision and Pattern Recognition · Computer Science 2025-07-16 Tianchi Xu

This work proposes to reduce visibility data volume using a baseline-dependent lossy compression technique that preserves smearing at the edges of the field-of-view. We exploit the relation of the rank of a matrix and the fact that a…

Instrumentation and Methods for Astrophysics · Physics 2023-04-17 M Atemkeng , S Perkins , E Seck , S Makhathini , O Smirnov , L Bester , B Hugo

We use the Global Historical Climatology Network--daily database to calculate trends in sea-level atmospheric pressures, their variance and the variance of their day-to-day differences in nine regions of the world. Changes in pressure…

Atmospheric and Oceanic Physics · Physics 2019-02-05 T. A. Howells , J. I. Katz

In a radio interferometer, the determination of geometrical antenna positions relies on accurate calibration of the dry and wet delay of the atmosphere above each antenna. For the Atacama Large Millimeter/Submillimeter Array (ALMA), which…

Instrumentation and Methods for Astrophysics · Physics 2016-10-14 Todd R. Hunter , Robert Lucas , Dominique Broguiere , Ed B. Fomalont , William R. F. Dent , Neil Phillips , David Rabanus , Catherine Vlahakis

Air contamination in urban areas has risen consistently over the past few years. Due to expanding industrialization and increasing concentration of toxic gases in the climate, the air is getting more poisonous step by step at an alarming…

Machine Learning · Computer Science 2021-05-13 Satvik Garg , Himanshu Jindal

Active Galactic Nuclei (AGNs) observed with the technique of very long baseline interferometry (VLBI) are used as fiducial references on the sky to precisely measure the shape and orientation of the Earth. Their positions form a celestial…

Astrophysics of Galaxies · Physics 2025-01-31 Ming Hui Xu , Patrick Charlot

This study focuses on inverting time-domain airborne electromagnetic data in 2D by training a neural-network to understand the relationship between data and conductivity, thereby removing the need for expensive forward modeling during the…