English
Related papers

Related papers: Bayesian self-calibration and imaging in Very Long…

200 papers

We present a stochastic, limited-memory Broyden Fletcher Goldfarb Shanno (LBFGS) algorithm that is suitable for handling very large amounts of data. A direct application of this algorithm is radio interferometric calibration of raw data at…

Instrumentation and Methods for Astrophysics · Physics 2019-04-16 Sarod Yatawatta , Lukas De Clercq , Hanno Spreeuw , Faruk Diblen

Hybrid analog-digital (HAD) architecture is widely adopted in practical millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems to reduce hardware cost and energy consumption. However, channel estimation in the…

Information Theory · Computer Science 2022-05-12 Jiabao Gao , Caijun Zhong , Geoffrey Ye Li , Joseph B. Soriaga , Arash Behboodi

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

We present results from a large global VLBI(Very Long Baseline Interferometry) survey of compact radio sources at 86 GHz which started in October 2001. The main goal of the survey is to increase the total number of objects accessible for…

Astrophysics · Physics 2009-04-14 S. Lee , A. P. Lobanov , T. P. Krichbaum , A. Witzel , J. A. Zensus , M. Bremer , A. Greve , M. Grewing

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2008-12-18 G. Bourda , P. Charlot , R. Porcas , S. Garrington

Recovering complex-valued image recovery from noisy indirect data is important in applications such as ultrasound imaging and synthetic aperture radar. While there are many effective algorithms to recover point estimates of the magnitude,…

Numerical Analysis · Mathematics 2024-03-26 Dylan Green , Jonathan Lindbloom , Anne Gelb

The Gaia celestial reference frame (Gaia-CRF) will benefit from a close assessment with independent methods, such as Very Long Baseline Interferometry (VLBI) measurements of radio stars at bright magnitudes. However, obtaining full…

Instrumentation and Methods for Astrophysics · Physics 2024-03-27 Jingdong Zhang , Bo Zhang , Shuangjing Xu , Niu Liu , Wen Chen , Hao Ding , Pengfei Jiang , Yan Sun , Jinqing Wang , Lang Cui , Shiming Wen , Xiaofeng Mai , Jinling Li , Fengchun Shu , Yidan Huang

Autonomous methods to align beamlines can decrease the amount of time spent on diagnostics, and also uncover better global optima leading to better beam quality. The alignment of these beamlines is a high-dimensional, expensive-to-sample…

We propose a method for automatic calibration of a traffic surveillance camera with wide-angle lenses. Video footage of a few minutes is sufficient for the entire calibration process to take place. This method takes in the height of the…

Computer Vision and Pattern Recognition · Computer Science 2020-01-22 Aman Gajendra Jain , Nicolas Saunier

Accurate camera-LiDAR calibration is a prerequisite for robust multi-modal perception in robotics. Recent target-less approaches based on deep point correspondences achieve remarkable performance for extrinsic calibration but assume…

Computer Vision and Pattern Recognition · Computer Science 2026-05-25 Simon Bultmann , Daniele Cattaneo , Abhinav Valada

Atmospheric propagation effects at millimeter wavelengths can significantly alter the phases of radio signals and reduce the coherence time, putting tight constraints on high frequency Very Long Baseline Interferometry (VLBI) observations.…

We present a Bayesian model for multi-resolution CMB component separation based on Wiener filtering and/or computation of constrained realizations, extending a previously developed framework. We also develop an efficient solver for the…

Instrumentation and Methods for Astrophysics · Physics 2019-07-10 D. S. Seljebotn , T. Bærland , H. K. Eriksen , K. -A. Mardal , I. K. Wehus

We introduce an algorithm for the deconvolution of radio synthesis images that accounts for the non-coplanar-baseline effect, allows multiscale reconstruction onto arbitrarily positioned pixel grids, and allows the antenna elements to have…

Instrumentation and Methods for Astrophysics · Physics 2013-10-09 Stephen J. Hardy

In this paper, we investigate the channel estimation problem for extremely large-scale multiple-input multiple-output (XL-MIMO) systems with a hybrid analog-digital architecture, implemented within a decentralized baseband processing (DBP)…

Information Theory · Computer Science 2025-04-29 Anzheng Tang , Jun-Bo Wang , Yijin Pan , Cheng Zeng , Yijian Chen , Hongkang Yu , Ming Xiao , Rodrigo C. de Lamare , Jiangzhou Wang

In this paper, we investigate the problem of inverse electromagnetic scattering to recover multilayer human tissue profiles using ultrawideband radar systems in a Bayesian setting. We study the recovery problem in a blind setting, in which…

Signal Processing · Electrical Eng. & Systems 2021-08-30 Burak Cevat Civek , Emre Ertin

The paper presents the results of the largest to date VLBI absolute astrometry campaign of observations of 13,645 radio sources with the Very Long Baseline Array (VLBA). Of them, 7220 have been detected, including 6755 target sources that…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Leonid Petrov

A new approach for blind channel equalization and decoding, variational inference, and variational autoencoders (VAEs) in particular, is introduced. We first consider the reconstruction of uncoded data symbols transmitted over a noisy…

Machine Learning · Computer Science 2020-04-14 Avi Caciularu , David Burshtein

Time-delay measurements of 0957+561 based on radio monitoring now agree with optical monitoring. Recent models incorporate many recent observations, but the systematic uncertainties in the models still dominate the uncertainty in the…

Astrophysics · Physics 2007-05-23 Deborah Haarsma , Joseph Leh'ar , Rennan Barkana

The performance of multipath-enhanced device-free localization severely depends on the information about the propagation paths within the network. While known for the line-of-sight, the propagation paths have yet to be determined for…

Signal Processing · Electrical Eng. & Systems 2024-08-15 Martin Schmidhammer , Christian Gentner , Michael Walter , Stephan Sand , Benjamin Siebler , Uwe-Carsten Fiebig

Gaussian graphical models are widely used to infer dependence structures. Bayesian methods are appealing to quantify uncertainty associated with structural learning, i.e., the plausibility of conditional independence statements given the…

Methodology · Statistics 2025-11-05 Deborah Sulem , Jack Jewson , David Rossell
‹ Prev 1 8 9 10 Next ›