Filters








7,076 Hits in 5.0 sec

Distributed image reconstruction for very large arrays in radio astronomy

Andre Ferrari, David Mary, Remi Flamary, Cedric Richard
2014 2014 IEEE 8th Sensor Array and Multichannel Signal Processing Workshop (SAM)  
Current and future radio interferometric arrays such as LOFAR and SKA are characterized by a paradox.  ...  We investigate here decentralized and distributed image reconstruction strategies which select, transfer and process only a fraction of the total data.  ...  INTRODUCTION Since the commissioning of the first large radio interferometers in the 70s and 80s (such as the VLA in the USA and the WSRT) radio astronomy in the range of large wavelengths has grown dramatically  ... 
doi:10.1109/sam.2014.6882424 dblp:conf/ieeesam/FerrariMFR14 fatcat:vmseansmpbe7fbueyh5prdvwiq

Introduction to the Issue on Signal Processing for Space Research and Astronomy

Amir Leshem, Julian Christou, Brian D. Jeffs, Ercan Kuruoglu, Alle-Jan van der Veen
2008 IEEE Journal on Selected Topics in Signal Processing  
Two papers discuss calibration of radio interferometers and feed arrays. image reconstruction in very large optical interferometers such as the VLTI and the LBT.  ...  Technological advances in the last decade have created possibilities for large distributed interferometric radio and optical telescopes with very large receiving areas, extremely large aperture, and a  ... 
doi:10.1109/jstsp.2008.2006397 fatcat:wbvphvxdjjd5xmimomogxnaeaa

Digital hologram reconstruction of radio telescope data

Peter Kellman, Steve Leonard, Eamon Barrett
1977 Applied Optics  
Wernecke at Stanford Radio Science Laboratory, and the IDIMS image processing facility at ESL, Incorporated, Sunnyvale, California.  ...  Optical processing may be necessary to meet the enormous data processing requirements of future radio telescopes-for example, the National Radio Astronomy Observatory Very Large Array presently under construction  ...  Less familiar are those for imaging incoherent sources. Such methods involve interferometry and are the basis for radio astronomy.  ... 
doi:10.1364/ao.16.001113 pmid:20168649 fatcat:5z4mss2q7rdgpmklsvl66u5num

Offline and online reconstruction for radio interferometric imaging [article]

Xiaohao Cai, Luke Pratley, Jason D. McEwen
2020 arXiv   pre-print
Radio astronomy is transitioning to a big-data era due to the emerging generation of radio interferometric (RI) telescopes, such as the Square Kilometre Array (SKA), which will acquire massive volumes  ...  In this article we review methods proposed recently to resolve the ill-posed inverse problem of imaging the raw visibilities acquired by RI telescopes in the big-data scenario.  ...  For example, representative next-generation radio interferometric (RI) telescopes -the LOw Frequency ARray (LO-FAR 1 , [6] ), the Extended Very Large Array (EVLA 2 ), the Australian Square Kilometre Array  ... 
arXiv:2004.06478v1 fatcat:mwpqxago2fb2plj7nyfvr3elg4

Compressed sensing for aperture synthesis imaging

Stephan Wenger, Soheil Darabi, Pradeep Sen, Karl-Heinz Glassmeier, Marcus Magnor
2010 2010 IEEE International Conference on Image Processing  
Based on the favorable results of our statistical evaluation, we present a practical method for interferometric image reconstruction that is evaluated on observational data from the Very Large Array (VLA  ...  Index Termsradio astronomy, synthetic aperture imaging, image reconstruction, interferometry  ...  The common image reconstruction method used in radio astronomy is the CLEAN algorithm [10] , dating back to 1974.  ... 
doi:10.1109/icip.2010.5652311 dblp:conf/icip/WengerDSGM10 fatcat:p4ykteiwj5hbdd3js6snwmp3ge

Page 353 of Astronomy and Astrophysics Vol. 261, Issue 1 [page]

1992 Astronomy and Astrophysics  
Astrophys. 261, 353-364 (1992) ASTRONOMY AND ASTROPHYSICS Radio-interferometric imaging of very large fields The problem of non-coplanar arrays T.J. Cornwell’ and R.A. Perley!  ...  For any line of sight to a point on the celestial sphere, the spatial frequencies used in a standard two-dimensional imag- ing scheme result from the projection of a three-dimensional distribution of sample  ... 

Astronomy and cosmology [From the Guest editors

Amir Leshem, Farzad Kamalabadi, Ercan Kuruoglu, Alle-Jan van der Veen
2010 IEEE Signal Processing Magazine  
very large.  ...  Radio astronomy is also one of the first fields where sparse reconstruction techniques have been implemented regularly since the early 1970s, where image sparseness is used to compensate for sub Nyquist  ... 
doi:10.1109/msp.2009.934928 fatcat:kjkt26y76jdtnirojtu3koam34

An Imaging Algorithm for a Lunar Orbit Interferometer Array

Qizhi Huang, Shijie Sun, Shifan Zuo, Fengquan Wu, Yidong Xu, Bin Yue, Reza Ansari, Xuelei Chen
2018 Astronomical Journal  
However, for such array the traditional imaging algorithm is not applicable: the field of view is very wide (almost whole sky), and for baselines distributed on a plane, there is a mirror symmetry between  ...  The algorithm is applicable and good maps could be reconstructed, even though for each baseline the sky blocking by the Moon is different.  ...  We thank our colleagues from the DSL team and the CE-4 piggybacking long wavelength astronomy micro-satellites team for many helpful discussions during the past several years which enhanced our understanding  ... 
doi:10.3847/1538-3881/aac6c6 fatcat:t3m2wh5nwrclxm4rwpfqqhlwfe

The TAIGA experiment: from cosmic ray to gamma-ray astronomy in the Tunka valley

N Budnev, I Astapov, P Bezyazeekov, A Bogdanov, V Boreyko, M Büker, M Brückner, A Chiavassa, O Chvalaev, O Gress, T Gress, O Grishin (+68 others)
2016 Journal of Physics, Conference Series  
m 2 and the radio array Tunka-Rex.  ...  The TAIGA array is a complex, hybrid detector for ground-based gamma-ray astronomy for energies from a few TeV to several PeV as well as for cosmic ray studies from 100 TeV to several EeV.  ...  solve all problems of very high energy gamma -astronomy.  ... 
doi:10.1088/1742-6596/718/5/052006 fatcat:njm3rps6wzejvjvkv2aon4vk4y

Multi-frequency-synthesis and wide-field imaging with the EVLA

Urvashi Rau, Sanjay Bhatnagar, Kumar Golap
2011 2011 XXXth URSI General Assembly and Scientific Symposium  
In this talk, we will describe the algorithms used for wide-field wide-band imaging with the EVLA (Expanded Very Large Array), and show imaging results that demonstrate our current capabilities.  ...  Imaging algorithms need to account for all these effects to reconstruct both the spatial and spectral structure of the sky brightness distribution over the wide fields-of-view allowed by the element response  ...  (Expanded Very Large Array).  ... 
doi:10.1109/ursigass.2011.6051223 fatcat:jsrfqhqvojhhvne3fwzwafmlgy

Signal processing challenges for radio astronomical arrays

S. J. Wijnholds, A.-J. van der Veen, F. De Stefani, E. La Rosa, A. Farina
2014 2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)  
Current and future radio telescopes, in particular the Square Kilometre Array (SKA), are envisaged to produce large images (> 10 8 pixels) with over 60 dB dynamic range.  ...  This poses a number of image reconstruction and technological challenges, which will require novel approaches to image reconstruction and design of data processing systems.  ...  In the next section, we provide a brief introduction to image reconstruction with radio astronomical imaging arrays.  ... 
doi:10.1109/icassp.2014.6854631 dblp:conf/icassp/WijnholdsVSRF14 fatcat:w67cbqqspfaz5h2xdz2hldnojq

High-resolution radio astronomy: an outlook for Africa [article]

Leonid I. Gurvits, Robert Beswick, Melvin Hoare, Ann Njeri, Jay Blanchard, Carla Sharpe, Adrian Tiplady, Aletha de Witt
2020 arXiv   pre-print
Very Long Baseline Interferometry (VLBI) offers unrivalled resolution in studies of celestial radio sources.  ...  This contribution briefly describes the status and near-term strategy for the AVN development as a southern extension of the EVN-AVN alliance and as an eventual bridge to the Square Kilometre Array (SKA  ...  ., for the dedicated VLBI network -the Very Long Baseline Array (VLBA, Napier et al. 1994 ) and the SKA (Lal et al. 2010, and references therein) .  ... 
arXiv:2001.04576v1 fatcat:223ukerhyfag5odq2kpfa3xwym

Sparse Image Reconstruction for the SPIDER Optical Interferometric Telescope [article]

Luke Pratley, Jason D. McEwen
2019 arXiv   pre-print
State of the art sparse radio interferometric image reconstruction techniques have been gaining traction in radio astronomy and reconstruct accurate images of the radio sky.  ...  interest for its possible applications in astronomy and space science.  ...  Interferometric imaging in the radio has proven to be a popular approach between 50 MHz and 100 GHz, with telescopes such as the Very Large Array (VLA) that have antenna arrays spread over 36 kilometers  ... 
arXiv:1903.05638v2 fatcat:rhbeyk3exrcphiqv7rkg2vatbe

TAIGA - a hybrid array for high energy gamma astronomy and cosmic ray physics

N. Budnev, I. Astapov, P. Bezyazeekov, V. Boreyko, A. Borodin, M. Brueckner, A. Chiavassa, A. Dyachok, O. Fedorov, A. Gafarov, A. Garmash, N. Gorbunov (+72 others)
2018 EPJ Web of Conferences  
For the energy range 30 -200 TeV the sensitivity of 10 km 2 area TAIGA array for the detection of local sources is expected to be 5 × 10 −14 erg cm −2 sec −1 for 300 h of observations.  ...  The low investments together with the high sensitivity for energies ≥ 30-50 TeV make this pioneering technique very attractive for exploring the galactic PeVatrons  ...  At present the Tunka Radio Extension (Tunka-Rex) is an array of 63 antennas distributed on an area of 3 km 2 .  ... 
doi:10.1051/epjconf/201819101007 fatcat:tzyzpukqxnemthl5eilol2sgg4

The application of compressed sensing techniques in radio astronomy

Anna M. M. Scaife, Yves Wiaux
2011 2011 XXXth URSI General Assembly and Scientific Symposium  
The optimal reconstruction of these signals is an important topic not only for current astronomical imaging but also that of the next generation of radio telescopes, for many of which image dynamic range  ...  The theory of compressed sensing demonstrates that incompletely sampled signals, such as those from an interferometer, may be accurately reconstructed when they are sparse or compressible in some basis  ...  Conclusions Compressed sensing offers a new framework for image reconstruction in radio interferometry.  ... 
doi:10.1109/ursigass.2011.6051225 fatcat:isai7f3b6rejthdvmixxjgdd2q
« Previous Showing results 1 — 15 out of 7,076 results