English
Related papers

Related papers: Baseline Dependent Averaging in Radio Interferomet…

200 papers

We propose a blind interference alignment (BIA) through staggered antenna switching scheme with no ideal channel assumption. Contrary to the ideal assumption that channels remain constant during BIA symbol extension period, when the…

Information Theory · Computer Science 2016-11-17 Heecheol Yang , Wonjae Shin , Jungwoo Lee

Bearing fault detection is a critical task in predictive maintenance, where accurate and timely fault identification can prevent costly downtime and equipment damage. Traditional attention mechanisms in Transformer neural networks often…

Machine Learning · Computer Science 2024-12-17 Marzieh Mirzaeibonehkhater , Mohammad Ali Labbaf-Khaniki , Mohammad Manthouri

Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Parisa Noorishad , Stefan J. Wijnholds , Arnold van Ardenne , Thijs van der Hulst

Motivated by modern data applications such as cryo-electron microscopy, the goal of classic multi-reference alignment (MRA) is to recover an unknown signal $f: \mathbb{R} \to \mathbb{R}$ from many observations that have been randomly…

Signal Processing · Electrical Eng. & Systems 2024-02-23 Liping Yin , Anna Little , Matthew Hirn

In this paper we present the electromagnetic modeling and beam pattern measurements of a 16-elements ultra wideband sparse random test array for the low frequency instrument of the Square Kilometer Array telescope. We discuss the importance…

Instrumentation and Methods for Astrophysics · Physics 2018-01-10 E. de Lera Acedo , P. Bolli , F. Paonessa , G. Virone , E. Colin-Beltran , N. Razavi-Ghods , I. Aicardi , A. Lingua , P. Maschio , J. Monari , G. Naldi , M. Piras , G. Pupillo

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the most sensitive ground-based, single-dish radio telescope on Earth. However, the original HI spectra produced by FAST are affected by standing waves. To maximize the…

Instrumentation and Methods for Astrophysics · Physics 2022-08-03 De-Jian Liu , Ye Xu , Ying-Jie Li , Ze-Hao Lin , Shuai-Bo Bian , Chao-Jie Hao

The beamforming performance of the uniform circular array (UCA) in near-field wideband communication systems is investigated. Compared to uniform linear array (ULA), UCA exhibits uniform effective array aperture in all directions, thus…

Information Theory · Computer Science 2024-04-04 Yunhui Guo , Yang Zhang , Zhaolin Wang , Yuanwei Liu

Preliminary specifications for the Square Kilometre Array (SKA) call for 25% of the total collecting area of the dish array to be located at distances greater than 180 km from the core, with a maximum baseline of at least 3000 km. The array…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 L. E. H. Godfrey , H. Bignall , S. Tingay , L. Harvey-Smith , M. Kramer , S. Burke-Spolaor , J. C. A. Miller-Jones , M. Johnston-Hollitt , R. Ekers , S. Gulyaev

Long baseline optical and infrared interferometric arrays achieve high angular resolution and enable detailed astrophysical measurements. Interferometers have enabled observations of stars at various stages of evolution, as well as studies…

Latent Dirichlet allocation (LDA) obtains essential information from data by using Bayesian inference. It is applied to knowledge discovery via dimension reducing and clustering in many fields. However, its generalization error had not been…

Machine Learning · Statistics 2021-01-26 Naoki Hayashi

With the high sensitivity and wide-field coverage of the Square Kilometre Array (SKA), large samples of explosive transients are expected to be discovered. Radio wavelengths, especially in commensal survey mode, are particularly well suited…

High Energy Astrophysical Phenomena · Physics 2016-11-23 Poonam Chandra , G. C. Anupama , K. G. Arun , Shabnam Iyyani , Kuntal Misra , D. Narasimha , Alak Ray , L. Resmi , Subhashis Roy , Firoza Sutaria

Dielectric disk accelerating (DDA) structures are being studied as an alternative to conventional disk-loaded copper structures. This paper investigates numerically an efficient X-band DDA structure operating at a higher order mode of…

Accelerator Physics · Physics 2021-06-09 Yelong Wei , Alexej Grudiev

Closure phases and closure amplitudes have proven critical to modern radio interferometry due to their insensitivity to the uncertain station gains. We present the first set of closure quantities constructed from parallel-hand and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-02 Avery E. Broderick , Dominic W. Pesce

This paper is an attempt to mitigate the beam squint happening due to frequency-dependent phase shifts in the wideband beamforming scenario, specifically in radar applications. The estimation of the direction of arrival is significant for…

Signal Processing · Electrical Eng. & Systems 2024-03-06 Neeraja P. K. , Bindiya T. S. , Raghu C.

Modern interferometric imaging relies on advanced calibration that incorporates direction-dependent effects. Their increasing number of antennas (e.g. in LOFAR, VLA, MeerKAT/SKA) and sensitivity are often tempered with the accuracy of their…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 K. Iheanetu , J. N. Girard , O. Smirnov , K. M. B. Asad , M. de Villiers , K. Thorat , S. Makhathini , R. A. Perley

Making sense of a dataset in an automatic and unsupervised fashion is a challenging problem in statistics and AI. Classical approaches for {exploratory data analysis} are usually not flexible enough to deal with the uncertainty inherent to…

The dispersive meshless method with scalar basis function has been successfully applied for analysis of frequency dependent media. However, as scalar based meshless methods are not always divergence-free in the absence of source,inaccurate…

Numerical Analysis · Mathematics 2020-12-21 Sheyda Shams , Masoud Movahhedi

This paper deals with the calibration of the analogue chains of a Square Kilometre Array (SKA) phased aperture array station, using embedded element patterns (one per antenna in the array, thus accounting for the full effects of mutual…

Instrumentation and Methods for Astrophysics · Physics 2020-06-14 Josef Borg , Alessio Magro , Kristian Zarb Adami , Eloy de lera Acedo , Adrian Sutinjo , Daniel Ung

Stacking as a tool for studying objects that are not individually detected is becoming popular even for radio interferometric data, and will be widely used in the SKA era. Stacking is typically done using imaged data rather than directly…

Instrumentation and Methods for Astrophysics · Physics 2015-01-26 K. K. Knudsen , L. Lindroos , W. Vlemmings , J. Conway , I. Marti-Vidal

We explore the possibilities of measuring the longitudinal profile of individual air showers beyond $X_{\rm max}$ when using very dense radio arrays such as SKA. The low-frequency part of the Square Kilometre Array, to be built in…

‹ Prev 1 4 5 6 7 8 10 Next ›