Publications

Ph.D. thesis

Stefan J. Wijnholds, "Fish-Eye Observing with Phased Array Radio Telescopes", Ph.D. thesis, Delft University of Technology, Delft, The Netherlands, 2 March 2010
abstract | full text (pdf)

Books and book chapters

Alle-Jan van der Veen, Stefan J. Wijnholds and Ahmad Mouri Sardarabadi, "Signal Processing for Radio Astronomy,". In: Shuvra S. Bhattacharyya, Ed F. Deprettere, Rainer Leupers and Jarmo Takala (Eds.), "Handbook of Signal Processing Systems", Third edition, Springer, ISBN 978-3-319-91733-7 / 978-3-319-91734-4 (eBook), pp311-360, 2019.

Jaap Bregman, Stefan Wijnholds and Michiel Brentjens, "Preparing for LOFAR." In: Richard Strom, Arnold van Ardenne and Steve Torchinsky (Eds.), "50 Years Westerbork Radio Observatory - A Continuing Journey to Discoveries and Innovations," ASTRON, ISBN 978-90-805434-0-9, pp151-154, 2018.

Alle-Jan van der Veen and Stefan J. Wijnholds, "Signal Processing Tools for Radio Astronomy". In: Shuvra S. Bhattacharyya, Ed F. Deprettere, Rainer Leupers and Jarmo Takala (Eds.), "Handbook of Signal Processing Systems", Second edition, Springer, ISBN 978-1-4614-6858-5, pp421-464, 2013.

International journal papers

  1. Steven Ndung'u, Trienko Grobler, Stefan J. Wijnholds, Dimka Karastoyanova and George Azzopardi, "Advances on the morphological classification of radio galaxies: A review," New Astronomy Reviews, V97, no. 101685, pp1-17, December 2023.
    DOI: 10.1016/j.newar.2023.101685
  2. Pietro Bolli, David B. Davidson, Maria Grazia Labate and Stefan J. Wijnholds, "Antenna Pattern Modeling Accuracy for a Very Large Aperture Array Radio Telescope With Strongly Coupled Elements," IEEE Antennas and Wireless Propagation Letters, V22, no. 11, pp2730-2734, November 2023.
    DOI: 10.1109/LAWP.2023.3280169
  3. A. M. Kutkin et al., "Apertif 1.4 GHz continuum observations of the Bootes field and their combined view with LOFAR," Astronomy & Astrophysics, V676, no. A37, pp1-13, August 2023.
    DOI: 10.1051/0004-6361/202346618
  4. Joeri van Leeuwen et al., "The Apertif Radio Transient System (ARTS): Design, commissioning, data release, and detection of the first five fast radio bursts," Astronomy & Astrophysics, V672, no. A117, pp1-38, April 2023.
    DOI: 10.1051/0004-6361/202244107
  5. Paola di Ninni, Mirko Bercigli, Pietro Bolli, Maria Grazia Labate and Stefan J. Wijnholds, "Mutual Coupling Mitigation in Array Dense Regime by an Antenna Distribution Optimization in SKA1-LOW," Radio Science, V57, no. e2022RS007507, pp1-14, November 2022.
    DOI: 10.1029/2022RS007507
  6. W. A. van Cappellen et al., "Apertif: Phased array feeds for the Westerbork Synthesis Radio Telescope - System overview and performance characteristics," Astronomy & Astrophysics, V658, no. A146, pp1-29, February 2022.
    DOI: 10.1051/0004-6361/202141739
  7. Anna Bonaldi, Stefan J. Wijnholds, Luca Stringhetti and Justin Jonas, "Special Section Guest Editorial: The SKA Observatory," SPIE Journal of Astronomical Telescopes, Instruments and Systems, V8(1), no. 011001, pp1-3, January - March 2022.
    DOI: 10.1117/1.JATIS.8.1.011001
  8. Cornelis R. Wilke, Stefan J. Wijnholds and Jacki Gilmore, "Calibratability of mid-frequency aperture arrays with self-holography," SPIE Journal of Astronomical Telescopes, Instruments and Systems, V8(1), no. 011008, pp1-11, January - March 2022.
    DOI: 10.1117/1.JATIS.8.1.011008
  9. Giuseppe Virone, Fabio Paonessa, Lorenzo Ciorba, Stefania Matteoli, Pietro Bolli, Stefan J. Wijnholds, Giuseppe Addamo, "Measurement of the LOFAR-HBA beam patterns using an unmanned aerial vehicle in the near field," SPIE Journal of Astronomical Telescopes, Instruments and Systems, V8(1), no. 011005, pp1-14, January - March 2022.
    DOI: 10.1117/1.JATIS.8.1.011005
  10. C. G. Bassa, J. W. Romein, B. Veenboer, S. van der Vlugt and S. J. Wijnholds, "Fourier-domain dedispersion," Astronomy & Astrophysics, V657, no. A46, pp1-7, January 2022.
    DOI: 10.1051/0004-6361/202142099
  11. Ridalise Louw, Ferre Knaepkens, Annie Cuyt, Wen-Shin Lee, Stefan J. Wijnholds, Dirk I. L. De Villiers and Rina-Mari Weideman, "Antenna Position Estimation Through Subsampled Exponential Analysis of Signals in the Near Field," URSI Radio Science Letters, V3, 2021.
    DOI: 10.46620/21-0062
  12. P. Benthem et al., "The Aperture Array Verification System 1: System overview and early commissioning results," Astronomy & Astrophysics, V655, no. A5, pp1-18, November 2021.
    DOI: 10.1051/0004-6361/202040086
  13. Cornelis R. Wilke, Stefan J. Wijnholds and Jacki Gilmore, "Calibratability of Aperture Arrays Using Self-Holography," IEEE Transactions on Antennas and Propagation, V69, no. 8, pp4527-4537, August 2021.
    DOI: 10.1109/TAP.2021.3060070
  14. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Mitigation of Non-Narrowband Radio Frequency Interference Incorporating Array Imperfections," Journal of Astronomical Instrumentation, V08, no. 01, 1940013, March 2019.
    DOI: 10.1142/S2251171719400130
    abstract | full text (pdf)
  15. Liying Wei and Stefan J. Wijnholds, "Joint calibration and imaging for phased array radio telescopes," Monthly Notices of the Royal Astronomical Society, V483, no. 4, pp5672-5686, March 2019.
    DOI: 10.1093/mnras/sty3419
    abstract | full text (pdf)
  16. Paola Di Ninni, Pietro Bolli, Fabio Paonessa, Giuseppe Pupillo, Giuseppe Virone and Stefan J. Wijnholds, "Electromagnetic Analysis and Experimental Validation of the LOFAR Radiation Patterns," International Journal of Antennas and Propagation, V2019, no. 9191580, pp1-12, January 2019.
    DOI: 10.1155/2019/9191580
    abstract | full text (pdf)
  17. Jan-WIllem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Mitigation of non-narrowband radio-frequency interference," URSI Radio Science Bulletin, V2018, no. 365, pp10-19, June 2018.
    DOI: 10.23919/URSIRSB.2018.8572495
    abstract | full text (pdf)
  18. S. J. Wijnholds, A. G. Willis and S. Salvini, "Baseline-dependent averaging in radio interferometry," Monthly Notices of the Royal Astronomical Society, V476, no. 2, pp2029-2039, May 2018.
    DOI: 10.1093/mnras/sty360
    abstract | full text (pdf)
  19. Giuseppe Virone et al., "Strong Mutual Coupling Effects on LOFAR: Modeling and In-Situ Validation," IEEE Transactions on Antennas and Propagation, V66, no. 5, pp2581-2588, May 2018.
    DOI: 10.1109/TAP.2018.2816651
    abstract | full text (pdf)
  20. Pietro Bolli, Giuseppe Pupillo, Fabio Paonessa, Giuseppe Virone, Stefan J. Wijnholds and Andrea Maria Lingua, "Near-Field Experimental Verification of the EM Models for the LOFAR Radio Telescope,", IEEE Antennas and Wireless Propagation Letters, V17, no. 4, pp613-616, April 2018.
    DOI: 10.1109/LAWP.2018.2805999
    abstract | full text (pdf)
  21. Martin Brossard, Mohammed Nabil El Korso, Marius Pesavento, Remy Boyer, Pascal Larzabal and Stefan J. Wijnholds, "Parallel multi-wavelength calibration algorithm for radio astronomical arrays," Signal Processing, V145, pp258-271, April 2018.
    DOI: 10.1016/j.sigpro.2017.12.014
    abstract | full text (pdf)
  22. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Computationally Efficient Radio Frequency Source Localization for Radio Interferometric Arrays." Radio Science, V53, no. 3, pp242-256, March 2018.
    DOI: 10.1002/2017RS006513
    abstract | full text (pdf)
  23. S. Chiarucci and S. J. Wijnholds, "Blind calibration of radio interferometric arrays using sparsity constraints and its implications for self-calibration," Monthly Notices of the Royal Astronomical Society, V474, no. 1, pp1028-1040, February 2018.
    DOI: 10.1093/mnras/stx2731
    abstract | full text (pdf)
  24. A. H. Patil et al., "Upper Limits on the 21 cm Epoch of Reionization Power Spectrum from One Night with LOFAR," The Astrophysical Journal, vol. 838, no. 1, March 2017.
    DOI: 10.3847/1538-4357/aa63e7
    abstract | full text (pdf)
  25. T. L. Grobler, A. J. Stewart, S. J. Wijnholds, J. S. Kenyon and O. M. Smirnov, "Calibration artefacts in radio interferometry - III. Phase-only calibration and primary beam correction," Monthly Notices of the Royal Astronomical Society, V461, no. 3, pp2975-2992, September 2016.
    DOI: 10.1093/mnras/stw1437
    abstract | full text (pdf)
  26. M. Mevius et al., "Probing ionospheric structures using the LOFAR radio telescope," Radio Science, V51, no. 7, pp927-941, July 2016.
    DOI: 10.1002/2016RS006028
    abstract | full text (pdf)
  27. S. J. Wijnholds, T. L. Grobler and O. M. Smirnov, "Calibration artefacts in radio interferometry. - II. Ghost patterns for irregular arrays," Monthly Notices of the Royal Astronomical Society, V457, no. 3, pp2331-2354, April 2016.
    DOI: 10.1093/mnras/stw118
    abstract | full text (pdf)
  28. H. K. Vedantham et al., "Lunar occultation of the diffuse radio sky: LOFAR measurements between 35 and 80 MHz," Monthly Notices of the Royal Astronomical Society, V450, no. 3, pp2291-2305, July 2015.
    DOI: 10.1093/mnras/stv746
    abstract | full text (pdf)
  29. G. Pupillo et al., "Medicina array demonstrator: calibration and radiation pattern characterization using a UAV-mounted radio-frequency source," Experimental Astronomy, V39, no. 2, pp405-421, June 2015.
    DOI: 10.1007/s10686-015-9456-z
    abstract | full text (pdf)
  30. A. Young, S.J. Wijnholds, T.D. Carozzi, R. Maaskant, M.V. Ivashina and D. Davidson, "Efficient correction for both direction-dependent and baseline-dependent effects in interferometric imaging: An A-stacking framework," Astronomy & Astrophysics, V577, no. A56, pp1-11, May 2015.
    DOI: 10.1051/0004-6361/201425492
    abstract | full text (pdf)
  31. Stefano Salvini and Stefan J. Wijnholds, "Fast gain calibration in radio astronomy using alternating direction implicit methods: Analysis and applications," Astronomy & Astrophysics, V571, no. A97, pp1-14, November 2014.
    DOI: 10.1051/0004-6361/201424487
    abstract | full text (pdf)
  32. Rik Jongerius, Stefan Wijnholds, Ronald Nijboer and Henk Corporaal, "An End-to-End Computing Model for the Square Kilometre Array," IEEE Computer, V47, no. 9, pp48-54, September 2014.
    DOI: 10.1109/MC.2014.235
    abstract | full text (pdf)
  33. Ajinkya H. Patil et al., "Constraining the epoch of reionization with the variance statistic: simulations of the LOFAR case," Monthly Notices of the Royal Astronomical Society, V443, no. 2, pp1113-1124, September 2014.
    DOI: 10.1093/mnras/stu1178
    abstract | full text (pdf)
  34. P. Prasad, S.J. Wijnholds, F. Huizinga and R.A.M.J. Wijers, "Real-time calibration of the AARTFAAC array for transient detection," Astronomy & Astrophysics, V568, no. A48, pp1-18, August 2014.
    DOI: 10.1051/0004-6361/201423668
    abstract | full text (pdf)
  35. H.K. Vedantham, L.V.E. Koopmans, A.G. de Bruyn, S.J. Wijnholds, B. Ciardi and M.A. Brentjens, "Chromatic effects in the 21 cm global signal from the cosmic dawn", Monthly Notices of the Royal Astronomical Society, V437, no. 2, pp1056-1069, January 2014
    DOI: 10.1093/mnras/stt1878
    abstract | full text (pdf)
  36. Stefan J. Wijnholds, Wim A. van Cappellen, Jan Geralt bij de Vaate and Arnold van Ardenne, "Phased-Array Antenna System Development for Radio-Astronomy Applications", IEEE Antennas and Propagation Magazine, V55, no. 6, pp293-308, December 2013
    DOI: 10.1109/MAP.2013.6781747
    abstract | full text (pdf)
  37. M.P. van Haarlem et al., "LOFAR: The Low Frequency Array", Astronomy & Astrophysics, V556, no. A2, pp1-53, August 2013
    DOI: 10.1051/0004-6361/201220873
    abstract | full text (pdf)
  38. Peeyush Prasad and Stefan J. WIjnholds, "Amsterdam-ASTRON radio transient facility and analysis centre: towards a 24 x 7, all-sky monitor for the low-frequency array (LOFAR)", Philosophical Transactions of the Royal Society A, V371, no. 1992, 13 June 2013
    DOI: 10.1098/rsta.2012.0234
    abstract | full text (pdf)
  39. Stefan J. Wijnholds, Marianna V. Ivashina, Rob Maaskant and Karl F. Warnick, "Polarimetry With Phased Array Antennas: Sensitivity and Polarimetric Performance Using Unpolarized Sources for Calibration", IEEE Transactions on Antennas and Propagation, V60, no. 10, pp4688-4698, October 2012
    DOI: 10.1109/TAP.2012.2207340, Copyright IEEE
    abstract | full text (pdf)
  40. P. Noorishad, S.J. Wijnholds, A. van Ardenne and J.M. van der Hulst, "Redundancy calibration of phased-array stations", Astronomy & Astrophysics, V545, no. A108, pp1-15, September 2012
    DOI: 10.1051/0004-6361/201219087
    abstract
  41. R. Maaskant, M.V. Ivashina, S.J. Wijnholds and K.F. Warnick, "Efficient Prediction of Array Element Patterns Using Physics-Based Expansions and a Single Far-Field Measurement", IEEE Transactions on Antennas and Propagation, V60, no. 8, pp3614-3621, August 2012
    DOI: 10.1109/TAP.2012.2201104, Copyright IEEE
    abstract | full text (pdf)
  42. Karl F. Warnick, Marianna V. Ivashina, Stefan J. Wijnholds and Rob Maaskant, "Polarimetry With Phased Array Antennas: Theoretical Framework and Definitions", IEEE Transactions on Antennas and Propagation, V60, no. 1, pp184-196, January 2012
    DOI: 10.1109/TAP.2011.2167926, Copyright IEEE
    abstract | full text (pdf)
  43. S. J. Wijnholds, J. D. Bregman and A. van Ardenne, "Calibratability and its impact on configuration design for the LOFAR and SKA phased array radio telescopes", Radio Science, V46, RS0F07, 8 November 2011
    DOI: 10.1029/2011RS004733
    abstract
  44. Stefan J. Wijnholds and Wim A. van Cappellen, "In Situ Antenna Performance Evaluation of the LOFAR Phased Array Radio Telescope", IEEE Transactions on Antennas and Propagation, V59, no. 6, pp1981-1989, June 2011
    DOI: 10.1109/TAP.2011.2122225, Copyright IEEE
    abstract | full text (pdf)
  45. Gideon W. Kant, Parbhu D. Patel, Stefan J. Wijnholds, Mark Ruiter and Erik van der Wal, "EMBRACE: A Multi-Beam 20,000-Element Radio Astronomical Phased Array Antenna Demonstrator", V59, no. 6, pp1990-2003, June 2011
    DOI: 10.1109/TAP.2011.2122233, Copyright IEEE
    abstract | full text (pdf)
  46. Stefan J. Wijnholds, Sebastiaan van der Tol, Ronald Nijboer and Alle-Jan van der Veen, "Calibration Challenges for Future Radio Telescopes", IEEE Signal Processing Magazine, V27, no. 1, pp30-42, January 2010
    DOI: 10.1109/MSP.2009.934853, Copyright IEEE
    abstract | full text (pdf)
  47. Stefan J. Wijnholds and Alle-Jan van der Veen, "Multisource Self-Calibration for Sensor Arrays", IEEE Transactions on Signal Processing, V57, no. 9, pp3512-3522, September 2009
    DOI: 10.1109/TSP.2009.2022894, Copyright IEEE
    abstract | full text (pdf)
  48. Stefan J. Wijnholds and Alle-Jan van der Veen, "Fundamental Imaging Limits of Radio Telescope Arrays", IEEE Journal of Selected Topics in Signal Processing, V2, no. 5, pp613-623, October 2008
    DOI: 10.1109/JSTSP.2008.2004216, Copyright IEEE
    abstract | full text (pdf)
  49. Stefan J. Wijnholds, Alle-Jan van der Veen, "Effects of Parametric Constraints on the CRLB in Gain and Phase Estimation Problems", IEEE Signal Processing Letters, V13, no. 10, pp620-623, October 2006
    DOI: 10.1109/LSP.2006.875348, Copyright IEEE
    abstract | full text (pdf)
  50. H. Falcke et al. (LOPES Collaboration), "Detection and imaging of atmospheric radio flashes from cosmic ray air showers", Nature, V435, pp313-316, May 2005
    abstract | full text (pdf)
  51. Stefan J. Wijnholds, A. Ger de Bruyn, Jaap D. Bregman, Jan Geralt bij de Vaate, "Hemispheric Imaging of Galactic Neutral Hydrogen with a Phased Array Antenna System", Experimental Astronomy, V17, pp59-64, 2004
    abstract | full text (pdf)
  52. Stefan J. Wijnholds, Jaap D. Bregman, Albert-Jan Boonstra, "Sky Noise Limited Snapshot Imaging in the Presence of RFI with LOFAR's Initial Test Station", Experimental Astronomy, V17, pp35-42, 2004
    abstract | full text (pdf)

Apertif Builder's List papers

  1. H. Denes et al., "Characterising the Apertif primary beam response," Astronomy & Astrophysics, V667, no. A40, pp1-13, November 2022.
    DOI: 10.1051/0004-6361/202244045
  2. A.M. Kutkin et al., "Continuum source catalog for the first APERTIF data releease," Astronomy & Astrophysics. V667, no. A39, pp1-12, November 2022.
    DOI: 10.1051/0004-6361/202244008
  3. E.A.K. Adams et al., "First release of Apertif imaging survey data," Astronomy & Astrophysics, V667, no. A38, pp1-19, November 2022.
    DOI: 10.1051/0004-6361/202244007
  4. B. Adebahr et al., "Apercal - The Apertif Calibration Pipeline," Astronomy and Computing, V38, no. 100514, pp1-15, January 2022.
    DOI: 10.1016/j.ascom.2021.100514
  5. Ines Pastor-Marazuela et al., Chromatic periodic activity down to 120 megahertz in a fast radio burst," Nature, no. 596, pp505-508, August 2021.
    DOI: 10.1038/s41586-021-03724-8
  6. K. M. Hess et al., "Apertif view of the OH Megamaser IRAS 10597+5926: OH 18 cm satellite lines in wide-area Hi surveys," Astronomy & Astrophysics, V647, no. A193, pp1-9, March 2021.
    DOI: 10.1051/0004-6361/202040019
  7. Liam Connor et al., "A bright, high rotation measure FRB that skewers the M33 halo," Monthly Notices of the Royal Astronomical Society, V499, no. 4, pp. 4716-4724, December 2020.
    DOI: 10.1093/mnras/staa3009
    abstract | full text (pdf)
  8. T. A. Oosterloo et al., "Extreme intra-hour variability of the radio source J1402+5347 discovered with Apertif," Astronomy & Astrophysics, V641, no. L4, pp. 1-11, 1 September 2020.
    DOI: 10.1051/0004-6361/202038378
    abstract | full text (pdf)
  9. L. C. Oostrum et al., "Repeating fast radio bursts with WSRT/Apertif," Astronomy & Astrophysics, V635, no. A61, pp. 1-11, 9 March 2020.
    DOI: 10.1051/0004-6361/201937422
    abstract | full text (pdf)

LOFAR Builder's List papers

  1. L. K. Morabito et al., "Sub-arcsecond imaging with the International LOFAR Telescope - I. Foundational calibration strategy and pipeline," Astronomy & Astrophysics, V658, no. A1, pp1-21, February 2022.
    DOI: 10.1051/0004-6361/202140649
  2. A. J. Stewart et al., "LOFAR MSSS: detection of a low-frequency radio transient in 400 h of monitoring of the North Celestial Pole," Monthly Notices of the Royal Astronomical Society, V456, no. 3, pp2321-2342, March 2016.
    DOI: 10.1093/mnras/stv2797
    abstract | full text (pdf)
  3. S. Buitink et al., "A large light-mass component of cosmic rays at 1017 - 1017.5 electronvolts from radio observations," Nature, V531, pp70-73, March 2016.
    DOI: 10.1038/nature16976
    abstract
  4. M. Pilia et al., "Wide-band, low-frequency pulse profiles of 100 radio pulses with LOFAR," Astronomy & Astrophysics, V586, no. A92, pp1-34, February 2016.
    DOI: 10.1051/0004-6361/201425196
    abstract | full text (pdf)
  5. A. Nelles et al., "Calibrating the absolute ampltiude scale for air showers measured at LOFAR," Journal of Instrumentation, V10, no. 11, pp. P11005, November 2015.
    abstract | full text (pdf)
  6. G. H. Heald et al., "The LOFAR Multifrequency Snapshot Sky Survey (MSSS) - I. Survey description and first results," Astronomy & Astrophysics, V582, no. A123, pp1-22, October2015.
    DOI: 10.1051/0004-6361/201425210
    abstract | full text (pdf)
  7. C. Sotomayor-Beltran et al., "Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes (Corrigendum)," Astronomy & Astrophysics, V581, no. C4, pp1-2, September 2015.
    DOI: 10.1051/0004-6361/201220728e
    absrtact of original paper | Erratum (pdf)
  8. A. Nelles et al., "Measuring a Cherenkov ring in the radio emission from air showers at 110-190 MHz with LOFAR," Astroparticle Physics, V65, pp11-21, May 2015.
    DOI: 10.1016/j.astropartphys.2014.11.006
    abstract | full text (pdf)
  9. H. Garsden et al., "LOFAR sparse image reconstruction," Astronomy & Astrophysics, V575, no. A90, pp1-18, March 2015.
    DOI: 10.1051/0004-6361/201424504
    abstract | full text (pdf)
  10. A. Corstanje et al., "The shape of the radio wavefront of extensive air showers as measured with LOFAR," Astroparticle Physics, V61, pp22-31, February 2015.
    DOI: 10.1016/j.astropartphys.2014.06.001
    abstract | full text (pdf)
  11. Thijs Coenen et al., "The LOFAR pilot surveys for pulsars and fast radio transients," Astronomy & Astrophysics, V570, no. A60, pp1-16, October 2014.
    DOI: 10.1051/0004-6361/201424495
    abstract | full text (pdf)
  12. V. Jelic et al., "Initial LOFAR observations of Epoch of Reionization windows: II. Diffuse polarized emission in the ELAIS-N1 field," Astronomy & Astrophysics, V568, no. A101, pp1-12, August 2014.
    DOI: 10.1051/0004-6361/201423998
    abstract | full text (pdf)
  13. P. Schellart et al., "Detecting Cosmic Rays with the LOFAR Radio Telescope", Astronomy & Astrophysics, V560, no. A98, pp1-14, December 2013
    DOI: 10.1051/0004-6361/201322683
    abstract | full text (pdf)
  14. A.R. Offringa et al., "The brightness and spatial distribution of terrestrial radio sources", Monthly Notices of the Royal Astronomical Society, V435, no. 1, pp584-596, October 2013
    DOI: 10.1093/mnras/stt1337
    abstract | full text (pdf)
  15. T.E. Hassall et al., "Differential Frequency-dependent Delay from the Pulsar Magnetosphere", Astronomy & Astrophysics, V552, no. A61, pp1-9, April 2013
    DOI: 10.1051/0004-6361/201220764
    abstract | full text (pdf)
  16. C. Sotomayor-Beltran et al., "Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes," Astronomy & Astrophysics, V552, no. A58, pp1-13, April 2013.
    DOI: 10.1051/0004-6361/201220728
    abstract | full text (pdf)
  17. S. Yatawatta et al., "Initial deep LOFAR observations of epoch of reionization windows - I. The north celestial pole", Astronomy & Astrophysics, V550, no. A136, pp1-17, February 2013
    DOI: 10.1051/0004-6361/201220874
    abstract | full text (pdf)
  18. A.R. Offringa et al., "The LOFAR radio environment", Astronomy & Astrophysics, V549, no. A11, pp1-15, January 2013
    DOI: 10.1051/0004-6361/201220293
    abstract
  19. T.E. Hassall et al., "Wide-band simultaneous observations of pulsars: disentangling dispersion measure and profile variations", Astronomy & Astrophysics, V543, no. A66, July 2012
    DOI: 10.1051/0004-6361/201218970
    abstract
  20. K. Singh et al., "Optimized trigger for ultra-high-energy cosmic-ray and neutrino observations with the low frequency radio array", Nuclear Instruments and Methods in Physics Research Section A, V664, issue 1, pp171-185, 1 February 2012
    DOI: 10.1016/j.nima.2011.10.041
    abstract
  21. B.W. Stappers et al., "Observing pulsars and fast transients with LOFAR", Astronomy & Astrophysics, V530, no. A80, June 2011
    DOI: 10.1051/0004-6361/201116681
    abstract

Refereed international conference papers

  1. Stefan J. Wijnholds, Maria Grazia Labate, David B. Davidson and Pietro Bolli, "Beam modelling accuracy for flux calibration of phased array radio telescopes,"2023 International Conference on Electromagnetics in Advanced Applications (ICEAA), Venice (Italy), 9 - 13 October 2023.
    DOI: 10.1109/ICEAA57318.2023.10297803
  2. Ridalise Raal, Rina-Mari Weideman, Dirk de Villiers, Annie Cuyt, Stefan J. Wijnholds, "Antenna Position Estimation Results from In-Situ Measurement Data," 2023 International Conference on Electromagnetics in Advanced Applications (ICEAA), Venice (Italy), 9 - 13 October 2023.
    DOI: 10.1109/ICEAA57318.2023.10297881
  3. Stefan J. Wijnholds et al., "Efficient Deconvolution of a Heterogeneous Array Observation Using a Direction-Dependent Point Spread Function," XXXVth URSI General Assmebly and Scientific Symposium (GASS), Sapporo (Japan), 19 - 26 August 2023.
    DOI: 10.23919/URSIGASS57860.2023.10265341
  4. Steven Ndung'u, Trienko Grobler, Stefan J. Wijnholds and George Azzopardi, "Deep supervised hashing for fast retrieval of radio image cubes," XXXVth URSI General Assmebly and Scientific Symposium (GASS), Sapporo (Japan), 19 - 26 August 2023.
    DOI: 10.23919/URSIGASS57860.2023.10265687
  5. Dijkema, Tammo Jan et al., "Developments on the LOFAR and SKA calibration and imaging software," Astronomical Data Analysis Software and Systems (ADASS) XXXII, hosted online by the Canadian Astronomy Data Centre, 31 October - 4 November 2022.
    abstract | full text (pdf)
  6. Stefan J. Wijnholds, "Reducing SKA-LOW Station Calibration Errors by Wideband Gain Model Fitting," 2022 International Conference on Electromagnetics in Advanced Applications (ICEAA), Cape Town (South Africa), 5 - 9 September 2022.
    DOI: 10.1109/ICEAA49419.2022.9899895
  7. Rina-Mari Weideman, Ridalise Louw, Ferre Knaepkens, Dirk De Villiers, Annie Cuyt, Wen-shin Lee and Stefan J. Wijnholds, "Simulated Performance of Antenna Position Estimation through Sub-Sampled Exponential Analysis," 2022 International Conference on Electromagnetics in Advanced Applications (ICEAA), Cape Town (South Africa), 5 - 9 September 2022.
    DOI: 10.1109/ICEAA49419.2022.9900012
  8. Stefan J. Wijnholds., "Keeping SKA1-LOW station beamforming errors acceptable," 2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC), Gran Canaria (Spain), 30 May - 4 June 2022.
    DOI: 10.23919/AT-AP-RASC54737.2022.9814381
  9. Chiara Salvoni et al., "Calibration and Imaging Pipeline Processing Baseline-dependent Averaged Visibilities," 2022 3rd URSI Atlantic and Asia Pacific Radio Science Meeting (AT-AP-RASC), Gran Canaria (Spain), 30 May - 4 June 2022.
    DOI: 10.23919/AT-AP-RASC54737.2022.9814290
  10. Cornelis Vertegaal, Hamid Reza Pourshaghaghi, Stefan Wijnholds and Mark Bentum, "Time Smearing in Space-based 3D Synthesis Imaging," 2022 IEEE Aerospace Conference (AERO), Big Sky, MT (USA), 5 - 12 March 2022.
    DOI: 10.1109/AERO53065.2022.9843284
  11. Stefan J. Wijnholds, "Generalised Self-Holography," XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Rome (Italy), 28 August - 4 September 2021.
    DOI: 10.23919/URSIGASS51995.2021.9560415
  12. Ridalise Louw, Ferre Knaepkens, Annie Cuyt, Wen-shin Lee, Stefan J. Wijnholds, Dirk L.L. de Villiers and Rina-Mari Weideman, "Antenna Position Estimation Through Sub-Sampled Exponential Analysis of Harmonically Related Input Signals, XXXIVth General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Rome (Italy), 28 August - 4 September 2021.
    DOI: 10.23919/URSIGASS51995.2021.9560519
  13. G. Virone et al., Preliminary Results on the Verification of the LOFAR-HBA with a Flying Test Source," 15th European Conference on Antennas and Propagation (EuCAP), Dusseldorf (Germany), 22 - 26 March 2021.
    DOI 10.23919/EuCAP51087.2021.9411311
  14. Stefan J. Wijnholds, "Embedded Element Patterns in Hierarchical Calibration of Large Distributed Arrays," XXXIIIrd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Rome (Italy), 29 August - 5 September 2020.
    abstract | full text (pdf)
  15. C. R. Wilke, S. J. Wijnholds and J. Gilmore, "Self-Holography - Slimming Down Calibration of Large Aperture Arrays," XXXIIIrd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Rome (Italy), 29 August - 5 September 2020.
    abstract | full text (pdf)
  16. Paola Di Ninni, Pietro Bolli, Fabio Paonessa, Giuseppe Pupillo, Giuseppe Virone and Stefan J. Wijnholds, "Comparison between Measured and Simulated Antenna Patterns for a LOFAR LBA array," 14th European Conference on Antennas and Propagation (EuCAP), Copenhagen (Denmark), 15 - 20 March 2020.
    abstract | full text (pdf)
  17. Stefan J. Wijnholds, Michel Arts, Pietro Bolli, Paola Di Ninni and Giuseppe Virone, "Using Embedded Element Patterns to Improve Aperture Array Calibration," International Conference on Electromagnetics in Advanced Applications (ICEAA), Granada (Spain), 9 - 13 September 2019.
    abstract | full text (pdf)
  18. P. Di Ninni, P. Bolli, R. Nesti, G. Virone, G. Pupillo and S. J. Wijnholds, "Antenna Phase Center Analysis for the LOFAR Radio Telescope," IEEE International Symposium on Antennas and Propagation (APS), Atlanta, Georgia (USA), 7 - 12 July 2019.
    abstract | full text (pdf)
  19. C. R. Wilke, S. J. Wijnhholds and J. Gilmore, "Performance Improvement of Self-Holography Based Aperture Array Station Calibration," European Conference on Antennas and Propagation (EUCAP), Krakow (Poland), 31 March - 5 April 2019.
    abstract | full text (pdf)
  20. Paola Di Ninni, Mirko Bercigli, Pietro Bolli, Giuseppe Virone and Stefan J. Wijnholds, "Mutual Coupling Analysis for a SKA1-LOW Station," European Conference on Antennas and Propagation (EUCAP), Krakow (Poland), 31 March - 5 April 2019.
    abstract | full text (pdf)
  21. Stefan J. Wijnholds, "Joint Imaging Across Multiple Beams," URSI Asia-Pacific Radio Science Conference (AP-RASC), New Delhi (India), 9-15 March 2019.
    abstract | full text (pdf)
  22. P. Krueger, M. Ruiter, S. J. Wijnholds and M. A. Brentjens, "RFI mitigation strategies for next generation phased array radio telescopes," URSI Asia-Pacific Radio Science Conference (AP-RASC), New Delhi (India), 9-15 March 2019.
    abstract | full text (pdf)
  23. Stefan J. Wijnholds, "Beam Shape Calibration for Multi-Beam Radio Astronomical Phased Arrays," European Signal Processing Conference (EuSiPCo), Rome (Italy), 3-7 September 2018.
    abstract | full text (pdf)
  24. P. Di Ninni et al., "Near-field validation of the electromagnetic model for LOFAR LBA-outer array," XXII Riunione Nazionale di Elettromagnetismo (RiNEm), Cagliari (Italy), 3-6 September 2018.
    abstract | full text (pdf)
  25. Stefan J. Wijnholds, "Assessing Polarimetric Performance in Scenarios with Spatially Non-White Noise", URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    abstract | full text (pdf)
  26. Stefan J. Wijnholds, "Blind calibration techniques for radio astronomical arrays," URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    extended abstract (pdf)
  27. Fabio Paonessa et al., "In-situ Verification of Aperture-Array Polarimetric Performance by means of a Micro UAV: Preliminary Results on the LOFAR Low Band Antenna", URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    abstract | full text (pdf)
  28. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Mitigation of Non-Narrowband Radio Frequency Interference," URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    abstract | full text (pdf)
  29. J. G. bij de Vaate, D. B. Davidson adn S. J. Wijnholds, "Regular Sparse Arrays: the Impact of Grating Lobes on Radio Astronomical Observations" URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    abstract | full text (pdf)
  30. J. G. bij de Vaate et al., "The SKA1_Low Telescope: Station Design and Prototyping," URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria (Spain), 28 May - 1 June 2018.
    extended abstract (pdf)
  31. Fabio Paonessa et al., "Differential Phase Patterns of the LOFAR LBA Array Measured In Situ," European Conference on Antennas and Propagation (EuCAP), London (UK), 9-13 April 2018.
    abstract | full text (pdf)
  32. Liying Wei, Stefan J. Wijnholds and Paul Hurley, "Robust recovery for aperture synthesis imaging," IEEE International Conference on Image Processing (ICIP), Beijing (China), 17-20 September 2017.
    abstract | full text (pdf)
  33. Stefan J. Wijnholds, "Calibration of Mid-Frequency Aperture Array Stations Using Self-holography," International Conference on Electromagnetics in Advanced Applications (ICEAA), Verona (Italy), 11-15 September 2017.
    abstract | full text (pdf)
  34. F. Paonessa et al., "Recent results on the characterization of the LOFAR radio telescope by means of a micro UAV," International Conference on Electromagnetics in Advanced Applications (ICEAA), Verona (Italy), 11-15 September 2017.
    abstract | full text (pdf)
  35. Stefan J. Wijnholds, "Constraining Ionospheric Models with Radio Interferometric Self-Calibration Data," URSI General Assembly and Scientific Symposium (URSI GASS), Montreal (Canada), 19-26 August 2017.
    abstract | full text (pdf)
  36. Stefano Salvini and Stefan J. Wijnholds, "High-compression Baseline Dependent Averaging," URSI General Assembly and Scientific Symposium (URSI GASS), Montreal (Canada), 19-26 August 2017.
    abstract | full text (pdf)
  37. A. G. Willis et al., "Analysis of Baseline-Dependent Averaging for the Square Kilometre Array," URSI General Assembly and Scientific Symposium (URSI GASS), Montreal (Canada), 19-26 August 2017.
    extended abstract (pdf)
  38. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Computationally Efficient Near-field Radio Frequency Source Localisation," URSI General Assembly and Scientific Symposium (URSI GASS), Montreal (Canada), 19-26 August 2017.
    abstract | full text (pdf)
  39. Pietro Bolli et al., "In-Situ Characterization of International Low-Frequency Aperture Arrays by Means of an UAV-based System," URSI General Assembly and Scientific Symposium (URSI GASS), Montreal (Canada), 19-26 August 2017.
    abstract | full text (pdf)
  40. Pieter van Vugt, Stefan Wijnholds, Arjan Meijerink and Mark Bentum, "Frequency smearing in full 3D interferometry," IEEE Aerospace Conference, Big Sky, Montana (USA), 4-11 March 2017.
    abstract | full text (pdf)
  41. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Spatial filtering of near-field radio frequency interference at a LOFAR LBA station," RFI worshop 2016, Socorro, New Mexico (USA), 17-20 October 2016.
    abstract | full text (pdf)
  42. Stefan J. Wijnholds and Simone Chiarucci, "Blind calibration of phased arrays using sparsity constraints on the signal model," 24th European Signal Processing Conference (EuSiPCo), Budapest (Hungary), 29 August - 2 September 2016.
    DOI: 10.1109/EUSIPCO.2016.7760252
    abstract | full text (pdf)
  43. Stefan J. Wijnholds, Giuseppe Pupillo, Pietro Bolli and Giuseppe Virone, "UAV-aided calibration for commissioning of phased array radio telescopes," URSI Asia-Pacific Radio Science Conference (URSI AP-RASC), Seoul (South Korea), 21-25 August 2016.
    DOI: 10.1109/URSIAP-RASC.2016.7601375
    abstract | full text (pdf)
  44. Stefan J. Wijnholds, "Blind calibration of dense irregular arrays by exploiting mulitply-measured nearly-identical spatial frequencies," IEEE International Symposium on Antennas and Propagation (APS), Fajardo (Puerto Rico), 26 June - 1 July 2016.
    DOI: 10.1109/APS.2016.7696172
    abstract | full text (pdf)
  45. P. Bolli et al., "Antenna pattern characterization of the low-frequency receptor of LOFAR by means of an UAV-mounted artificial test source," Proceedings SPIE 9906: Ground-based and Airborne Telescopes VI, Edinburgh (UK), 26 June 2016.
    DOI: 10.1117/12.2232419
    abstract | full text (pdf)
  46. A. Young, D.B. Davidson, S.J. Wijnholds, T.D. Carozzi, R. Maaskant and M.V. Ivashina, "Efficient Wideband Gain Modeling for Interferometric Imaging Arrays in Radio Astronomy," IEEE International Symposium on Antennas and Propagation (APS), Vancouver, BC (Canada), 19-24 July 2015.
    DOI: 10.1109/APS.2015.7305076
    abstract | full text (pdf)
  47. Stefan J. Wijnholds, "Fundamental Accuracy Limits of Ionospheric Characterization by Radio Interferometers," URSI Atlantic Radio Science Conference (URSI AT-RASC), Gran Canaria (Spain), 16-24 May 2015.
    DOI: 10.1109/URSI-AT-RASC.2015.7303209
    extended abstract (pdf)
  48. Peeyush Prasad, Stefan J. Wijnholds and R.A.M.J. Wijers, "All-Sky synthesis imaging for optimum transient detection in Radio Astronomy," URSI Atlantic Radio Science Conference (URSI AT-RASC), Gran Canaria (Spain), 16-24 May 2015.
    DOI: 10.1109/URSI-AT-RASC.2015.7303185
    extended abstract (pdf)
  49. Amir Leshem and Stefan J. Wijnholds, "Imaging and Calibration for Aperture Array Radio Telescopes," IEEE International Conference on Acoustics, Speech and Signal Processing, Tutorial Lecture T14, Brisbane (Australia), 19-24 April 2015.
    abstract
  50. Stefan J. Wijnholds and Jaap D. Bregman, "Calibratability by design for SKA's Low Frequency Aperture Array," XXXIth URSI General Assembly and Scientific Symposium, Beijing (China), 16-23 August 2014.
    DOI: 10.1109/URSIGASS.2014.6930060
    abstract | full text (pdf)
  51. Stefano Salvini and Stefan J. Wijnholds, "StEFCal - An Alternating Direction Implicit Method for Fast Full Polarization Array Calibration." XXXIth General Assembly and Scientific Symposium, Beijing (China), 16-23 August 2014.
    DOI: 10.1109/URSIGASS.2014.6930038
    abstract | full text (pdf)
  52. S.J. Wijnholds, A.J. van der Veen, F. De Stefani, E. La Rosa and A. Farina, "Signal Processing Challenges for Radio Astronomical Arrays", IEEE International Conference on Acoustics, Speech and Signal Processing, Florence (Italy), 4-9 May 2014
    abstract | full text (pdf)
  53. Yuntao Wu, Amir Leshem and Stefan J. Wijnholds, "A Computationally Efficient Calibration Algorithm for the LOFAR Radio Astronomical Array", IEEE International Conference on Acoustics, Speech and Signal Processing, Florence (Italy), 4-9 May 2014
    abstract | full text (pdf)
  54. Stefan J. Wijnholds and Rik Jongerius, "Computing Cost of Sensitivity and Survey Speed for Aperture Array and Phased Array Feed Systems", IEEE AfriCon / URSI BEJ meeting, Pointe-Aux-Piments (Mauritius), 9-12 September 2013
    abstract | full text (pdf)
  55. Stefan J. Wijnholds, Wim A. van Cappellen and Jan Geralt bij de Vaate, "Advances in Phased Array Systems for Radio Astronomy", IEEE International Symposium on Antennas and Propagation (APS), Orlando, Florida (USA), 7-13 July 2013
    abstract | full text (pdf)
  56. A. van Ardenne, J.G. bij de Vaate, B. Fiorelli and S.J. Wijnholds, "Wideband Array Developments for Planned and Future Radio Astronomy Antennas", European Conference on Antennas and Propagation (EuCAP), Goteborg (Sweden), 8-12 April 2013
    abstract | full text (pdf)
  57. David M.P. Smith, Michel J. Arts, Albert-Jan Boonstra and Stefan J. Wijnholds, "Characterisation of astronomical antenna for space based low frequency radio telescope", IEEE Aerospace Conference, Big Sky, MT (USA), 2-9 March 2013
    abstract | full text (pdf)
  58. Stefan Wijnholds, Ahmad Mouri Sardarabadi and Alle-Jan van der Veen, "Factor Analysis as a Tool for Signal Processing", Biomedical and Astronomical Signal Processing (BASP) Frontiers Workshop, Villars-sur-Ollon (Switzerland), 27 January - 1 February 2013
    extended abstract (pdf)
  59. Stefan J. Wijnholds, "Blind Self-Calibration of Sensor Arrays", Biomedical and Astronomical Signal Processing (BASP) Frontiers Workshop, Villars-sur-Ollon (Switzerland), 27 January - 1 February 2013
    extended abstract (pdf)
  60. Wim A. van Cappellen and Stefan J. Wijnholds, "Polarimetric Calibration Results of an APERTIF Phased Array Feed", International Conference on Electromagnetics in Advanced Applications (ICEAA), Cape Town (South Africa), 2-7 September 2012
    abstract | full text (pdf)
  61. Stefan J. Wijnholds and Parisa Noorishad, "Statistically Optimal Self-Calibration of Regular Imaging Arrays", 20th European Signal Processing Conference (EuSiPCo), Bucharest (Romania), 27-31 August 2012
    abstract | full text (pdf)
  62. W.A. van Cappellen, S.J. Wijnholds and L. Bakker, "High Sensitivity L-band Phased Array Feeds for the Westerbork Synthesis Radio Telescope", 6th European Conference on Antennas and Propagation (EuCAP), Prague (Czech Republic), 26-30 March 2012
    abstract | full text (pdf)
  63. Stefan J. Wijnholds, Wim van Cappellen and Marianna V. Ivashina, "Performance Assessment of Bi-scalar Beamformers in Practical Phased Array Feed Systems". General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Istanbul (Turkey), 13-20 August 2011
    abstract | full text (pdf)
  64. Stefan J. Wijnholds, Ronald Nijboer, Keith Grainge and Jaap D. Bregman, "Overview of SKA Calibration Challenges and Impact of Design Decisions". General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Istanbul (Turkey), 13-20 August 2011
    abstract | full text (pdf)
  65. Marianna V. Ivashina, Stefan J. Wijnholds, Rob Maaskant and Karl F. Warnick, "Performance of Polarimetric Beamformers for Phased Array Radio Telescopes". General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Istanbul (Turkey), 13-20 August 2011
    abstract | full text (pdf)
  66. P. Noorishad, S.J. Wijnholds, A. van Ardenne and J.M. van der Hulst, "Application of Redundancy Calibration to Phased Arrays and Some Limitations". General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), Istanbul (Turkey), 13-20 August 2011
    abstract | full text (pdf)
  67. Karl F. Warnick, Marianna Ivashina, Stefan Wijnholds and Rob Maaskant, "Beamforming, Calibration and Figures of Merit for Polarimetric Phased Array Antennas", IEEE International Symposium on Antennas and Propagation and USNC/URSI National Radio Science Meeting, Spokane (USA), 3-8 July 2011
    abstract
  68. Stefan J. Wijnholds and Alle-Jan van der Veen, "Data Driven Model Based Least Squares Image Reconstruction for Radio Astronomy". IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Prague (Czech Republic), 22-27 May 2011
    abstract | full text (pdf)
  69. P. Benthem, G.W. Kant, S.J. Wijnholds, M.J. Arts, M. Ruiter and E. van der Wal, "Aperture Array Development for Future Large Radio Telescopes". 5th European Conference on Antennas and Propagation (EuCAP), Rome (Italy), 11-15 April 2011
    abstract | full text (pdf)
  70. S.J. Wijnholds, "LOFAR - The First Operational Precursor to the SKA" , Asia-Pacific Radio Science Conference (AP-RASC'10), Toyama (Japan), 22-26 September 2010
    extended abstract (pdf)
  71. P. Noorishad, S.J. Wijnholds, A. van Ardenne and Thijs van der Hulst, "Applicability of Redundancy Calibration on Dense Phased Arrays", in: S.A. Torchinsky et al., "Wide Field Astronomy & Technology for the Square Kilometre Array - SKADS conference 2009", pp215-220, Limelette (Belgium), 4-6 November 2009
    abstract | full text (pdf)
  72. A.O.H. Olofsson et al., "Profiling the EMBRACE tile beam using GPS satellite carriers", in: S.A. Torchinsky et al., "Wide Field Astronomy & Technology for the Square Kilometre Array - SKADS conference 2009", pp253-258, Limelette (Belgium), 4-6 November 2009
    abstract | full text (pdf)
  73. S.J. Wijnholds et al., "EMBRACE: First Experimental Results with the Initial 10% of a 10,000 Element Phased Array Radio Telescope", in: S.A. Torchinsky et al., "Wide Field Astronomy & Technology for the Square Kilometre Array - SKADS conference 2009", pp259-264, Limelette (Belgium), 4-6 November 2009
    abstract | full text (pdf)
  74. Stefan J. Wijnholds and Alle-Jan van der Veen, "Self-Calibration of Radio Astronomical Arrays with Non-Diagonal Noise Covariance Matrix", 17th European Signal Processing Conference (EuSiPCo), Glasgow (UK), 24-28 August 2009
    abstract | full text (pdf)
  75. Stefan J. Wijnholds, "Fish-Eye Imaging With A LOFAR Station", URSI Benelux Forum, Delft (The Netherlands), 8 June 2009
    extended abstract (pdf)
  76. Stefan J. Wijnholds, "Autonomous Online LOFAR Station Calibration", URSI GA 2008, Chicago (Illinois, USA), 7-16 August 2008
    extended abstract (pdf)
  77. Stefan J. Wijnholds, "Calibration of Phased Array Radio Telescopes", URSI Benelux Forum, Brussels (Belgium), 30 May 2008
    extended abstract (pdf)
  78. W.A. van Cappellen, S.J. Wijnholds, J.D. Bregman, "Sparse Antenna Array Configurations in Large Aperture Synthesis Radio Telescopes", European Radar Conference (EuRAD), 13-15 September 2006
    abstract | full text (pdf)
  79. H. Falcke et al., "A very brief description of LOFAR - the Low Frequency Array", XXVIth IAU General Assembly, August 2006, in: Highlights of Astronomy, V14
    full text (pdf)
  80. Stefan J. Wijnholds, Albert-Jan Boonstra, "A Multisource Calibration Method for Phased Array Radio Telescopes", 4th IEEE workshop on Sensor Array and Multichannel Processing (SAM), Waltham (MA), 12-14 July 2006
  81. Sebastiaan van der Tol, Stefan J. Wijnholds, "CRB Analysis of the Impact of Unknown Receiver Noise in Phased Array Calibration", 4th IEEE workshop on Sensor Array and Multichannel Processing (SAM), Waltham (MA), 12-14 July 2006
  82. H.J.A. Roettgering et al., "LOFAR - Opening up a New Window on the Universe", SKA Conference 2006, 10-12 April 2006. In: H.-R. Kloeckner, M. Jarvis, S. Rawlings (eds.), "Cosmology, Galaxy Formation and Astroparticle Physics on the Pathway to the SKA"
  83. Albert-Jan Boonstra, Stefan J. Wijnholds, "Implementation of the LOFAR Interference Mitigation Strategy, Considerations and Tradeoffs", URSI GA 2005, New Delhi (India), October 2005
  84. Stefan J. Wijnholds, "Confusion Limited All Sky Imaging With LOFAR's Initial Test Station Applying Wide Field Calibration Techniques", URSI GA 2005, New Delhi (India), October 2005
  85. A.J. Boonstra, S.J. Wijnholds, S. van der Tol (TUD), B. Jeffs (TUD), "Calibration, Sensitivity and RFI Mitigation Requirements for LOFAR", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 18-23 March 2005, Philadelphia (Pennsylvania), V5, pp 869-872

Other conference, workshop and seminar contributions

  1. Stefan J. Wijnholds and Vincent Morello, "SDP AA2 pipeline benchmarking results," SKA Data Processing PI Demo, 23 November 2023.
  2. Stefan J. Wijnholds and Vincent Morello, "SDP-G2: SDP Mid and Low imaging pipeline scaling for AA2," SKA Data Processing PI Demo, 30 May 2023.
  3. Stefan J. Wijnholds, "SKA Science Data Handling & Processing (SDH&P)," SKA Regioanl Center meeting, 7 February 2023.
  4. Stefan J. Wijnholds, "Exponentials in radio astronomical data processing," EXPOWER kick-off meeting, 16 - 19 May 2022.
  5. Stefan J. Wijnholds, "Summary of SKA-LOW stability studies," SKA-LOW Meeting 2022, 8 February 2022.
  6. Stefan J. Wijnholds, "Massive correlation vs. massive beamforming," AARTFAAC 2.0 Workshop, Dwingeloo (The Netherlands), 12 February 2019.
  7. Stefan J. Wijnholds, "A short intro to interferometry," lecture at the University of Stellenbosch, Stellenbosch (South Africa), 12 October 2018.
  8. Stefan J. Wijnholds, "In-Situ Characterization of the Low-Frequency Array (LOFAR) by Means of an UAV-based System," KIvI-URSI meeting on "Radio Science in The Netherlands", Utrecht (The Netherlands), 13 March 2018.
  9. Stefan J. Wijnholds, "(Self-)calibration: from knowing everything to knowing nothing at all," WimSym77, Dwingeloo (The Netherlands), 6-7 July 2017.
  10. Jan-Willem W. Steeb, David B. Davidson and Stefan J. Wijnholds, "Wideband RFI mitigation," Detection and measurement of RFI in radio astronomy, Yebes Observatory (Spain), 8-9 June 2017.
  11. Stefan J. Wijnholds, "Ionospheric calibratability of SKA-low," Realising SKA-low Conference, Perth (Australia), 29-31 March 2017.
  12. B. Hut, S. J. Wijnholds and W. A. van Cappellen, "Online Calibration Scheme for APERTIF," Phased Array Feed Workshop, Cagliari (Italy), 24-26 August 2016.
  13. Stefan J. Wijnholds, "AA-mid calibratability requirements," MIDprep workshop, Cape Town (South Africa), 7-9 March 2016.
  14. Stefan J. Wijnholds, "Core-to-halo ratio, station size and ``sea(s) of elements''," SKA-low Calibration Consultation Meeting, Manchester (UK), 25 February 2016.
  15. Stefan J. Wijnholds, "Fundamental Limits of Direction Dependent Calibration," seminar at SKA South Africa Offices, Cape Town (South Africa), 28 January 2016.
  16. Stefan J. Wijnholds, "Ionospheric calibratability of SKA-low," SKA-low Calibration Consultation Meeting, Manchester (UK), 1 December 2015.
  17. Stefan J. Wijnholds, "Analysis of (u, v)-coverage of SKA-low," SKA-low Calibration Consultation Meeting, Mancheter (UK), 1 December 2015.
  18. Stefan J. Wijnholds, "Calibratability of a SKA-size MFAA," MIDprep workshop, Aveiro (Portugal), 20-22 April 2015.
  19. Stefan J. Wijnholds, "Calibratability of SKA-low in view of ionospheric conditions," SKA-low Calibration Consultation Workshop, Manchester (UK), 14 April 2015.
  20. Stefan J. Wijnholds, "Station calibration: from LOFAR to SKA-low," SKA-low Calibration Consultation Workshop, Manchester (UK), 14 April 2015.
  21. A. Young, S. J. Wijnholds, T. D. Carozzi, R. Maaskant, M. V. Ivashina and D. B. Davidson, "Efficient Correction for Both Direction-Dependent and Baseline-Dependent Gain Effects: An A-Stacking Framework," Royal Society Workshop on Next-Generation Radio Interferometric Imaging for the SKA, Stellenbosch (South Africa), March 2015.
  22. Stefan J. Wijnholds, "A noise budget for SKA imaging observations," SKA South Africa Bursary Conference, Stellenbosch (South Africa), 4-8 December 2014.
  23. Stefan J. Wijnholds, "Comparative Analysis of Performance and Computing for MFAA." Seminar at Stellenbosch University, Stellenbosch (South Africa), 1 December 2014.
  24. Stefan J. Wijnholds, "Advances in Phased Array Systems for Radio Astronomy," Seminar at Stellenbosch University, Stellenbosch (South Africa), 1 December 2014.
  25. Stefan J. Wijnholds, "Calibratability-by-design for AERA3", MIDprep Meeting, Dwingeloo (The Netherlands), 1 April 2014
  26. Stefan J. Wijnholds, "A noise budget for SKA imaging applications", SKA Calibration & Imaging Workshop, Kiama (Australia), 3-7 March 2014
  27. Peeyush Prasad, Stefan J. Wijnholds and Ralph Wijers, "Real-Time Wide-Field Calibration and Imaging for AARTFAAC All Sky Monitor", The Modern Radio Universe (MRU) Conference, Bonn (Germany), 22-26 April 2013
  28. Peeyush Prasad, Stefan J. Wijnholds and Ralph Wijers, "Real-Time Wide-Field Calibration for the AARTFAAC ASM", LOFAR Science Workshop, Dalfsen (The Netherlands), 19 March 2013
  29. Stefan J. Wijnholds, "Phased Array Feeds: Calibration & Beamforming", 3rd Generation Calibration (3GC) Workshop, Port Alfred (South Africa), 10-22 February 2013
  30. Stefan J. Wijnholds, "The dust under the carpet", 3rd Generation Calibration (3GC) Workshop, Port Alfred (South Africa), 10-22 February 2013
  31. Stefan J. Wijnholds, "Deep Calibration & Imaging With SKA - Where we are and where we should be going", SKA Calibration & Imaging Workshop, Cape Town (South Africa), 3-7 December 2012
    abstract
  32. Stefan J. Wijnholds, "System Requirements Derived from Calibratability", Aperture Array Calibration & Calibratability Meeting (AACal), Amsterdam (The Netherlands), 12-13 July 2012
  33. Stefan J. Wijnholds, Rob Maaskant and Marianna V. Ivashina, "Efficient Modeling of Beam Patterns Using Physics-Based Basis Functions", Aperture Array Calibration & Calibratability Meeting (AACal), Amsterdam (The Netherlands), 12-13 July 2012
  34. Stefan J. Wijnholds, "Self-Calibration of Non-Redundant Arrays Using Redundancy Calibration", Astronomical Data Analysis Conference VII (ADA7), Cargese (France), 14-18 May 2012
  35. Stefan J. Wijnholds, "AA Station Beam Accuracy", Aperture Array Verification Programme (AAVP) Workshop 2011, Dwingeloo (The Netherlands), 12-15 December 2011
  36. Stefan J. Wijnholds, "Identifiability of DDEs", Second Workshop on 3rd Generation Calibration (3GC-II), Albufeira (Portugal), 19-30 September 2011
  37. Stefan J. Wijnholds, "Calculating Beam Pattern Inaccuracies and Their Implications", Second Workshop on 3rd Generation Calibration (3GC-II), Albufeira (Portugal), 19-30 September 2011
  38. Stefan J. Wijnholds, "The Model Based Approach - A New View on Calibration and Imaging", SKA-low Workshop, Perth (Australia), 6-9 September 2011
  39. Stefan J. Wijnholds, Keith J. B. Grainge and Ronald Nijboer, "An Update from the Calibration & Imaging Working Group", SKA-low Workshop, Perth (Australia), 6-9 September 2011
  40. Stefan J. Wijnholds, "Beam Quality and Stability of PAF Systems", SKA Calibration & Imaging Workshop, Manchester (UK), 25-29 July 2011
    abstract
  41. Stefan J. Wijnholds, "Antenna Imaging with the Square Kilometre Array", European School of Antennas (ESoA) on Antenna Imaging Techniques, Delft (The Netherlands), 30 June 2011
  42. Stefan J. Wijnholds, "A Model Based Approach to LOFAR Calibration and Imaging", AAVP Workshop, Cambridge (UK), 8-10 December 2010
    abstract
  43. Stefan J. Wijnholds and Gideon W. Kant, "EMBRACE - Current Status, Early Results and Next Steps", SKA Annual Work Package 2 (WP2) Meeting, Oxford (UK), 27-30 October 2010
  44. Stefan J. Wijnholds, "Full Polarization Calibration of Phased Array Systems", SKA Calibration & Imaging Workshop, Dwingeloo (The Netherlands), 23-27 August 2010
  45. M.V. Ivashina, S.J. Wijnholds, R. Maaskant, K.F. Warnick and B. Jeffs, "Polarimetric Beamforming Methods for PAF Systems - Numerical Results for the APERTIF Prototype", SKA Calibration & Imaging Workshop, Dwingeloo (The Netherlands), 23-27 August 2010
  46. Stefan J. Wijnholds, "Aperture Array Developments at ASTRON", International Workshop on Phased Array Antenna Systems for Radio Astronomy, Provo (Utah, USA), 3-5 May 2010
    extended abstract (pdf)
  47. Stefan J. Wijnholds, "Calibration of Radio Astronomical Phased Arrays", International Workshop on Phased Array Antenna Systems for Radio Astronomy, Provo (Utah, USA), 3-5 May 2010
    extended abstract (pdf)
  48. Stefan J. Wijnholds, "Imaging with the SKA core", SKA2010 - International SKA Science and Engineering Meeting, Manchester (UK), 22-25 March 2010
    extended abstract
  49. P. Noorishad, S.J. Wijnholds, A. van Ardenne and J.M. van der Hulst, "Redundancy calibration in new radio telescopes", SKA2010 - International SKA Science and Engineering Meeting, Manchester (UK), 22-25 March 2010
    abstract
  50. Stefan J. Wijnholds, "Least Squares All-sky Synthesis Imaging With A LOFAR Station", SKA Calibration & Imaging Workshop, Socorro (New Mexico, USA), 30 March - 3 April 2009
  51. Stefan J. Wijnholds, "High DR Imaging with Signal Processing Techniques", MCCT SKADS Workshop, Cambridge (UK), 25-29 August 2008
  52. Stefan J. Wijnholds, "Autonomous Online LOFAR Station Calibration - Methods and Results", SKA Calibration & Imaging Workshop, Perth (Australia), 7-9 April 2008
  53. Stefan J. Wijnholds, "Effective Noise", SKA Calibration & Imaging Workshop, Perth (Australia), 7-9 April 2008
    54. abstract
  54. Stefan J. Wijnholds, "Overview of Measurement and Calibration Methods" , MCCT SKADS workshop, Dwingeloo (The Netherlands), 26-30 November 2007
  55. Stefan J. Wijnholds, "LOFAR on the Moon: Science & System Concept", Nederlandse Astronomen Conferentie (NAC), Veldhoven (The Netherlands), 14-16 May 2007
  56. Stefan J. Wijnholds, "Reducing the Impact of Station Level Spatial Filtering Limitations", SKA Calibration and Imaging Workshop, Cape Town (South-Africa), 4-6 December 2006
  57. Wim van Cappellen, Stefan J. Wijnholds, "The APERTIF Project", SKA Calibration and Imaging Workshop, Cape Town (South-Africa), 4-6 December 2006
  58. Stefan J. Wijnholds, "Automated Online Calibration of the LOFAR LBA Station Array", Young European Radio Astronomers Conference (YERAC), Dalfsen (The Netherlands), 12-15 September 2006
  59. Stefan J. Wijnholds, "Self-noise in full sky LOFAR images", Nederlands Astronomen Conferentie (NAC), 10-12 May 2006
  60. S.J. Wijnholds, "LOFAR's First All Sky Map", Nederlandse Astronomen Conferentie (NAC), Blankenberge (Belgium), May 2005
  61. D.M. Salter et al., "LOFAR - The New Eye for the Low-Frequency Universe", 205th meeting of the American Astronomical Society, San Diego (California), January 2005
  62. Stefan J. Wijnholds, Jaap D. Bregman, Albert-Jan Boonstra, "Sky Noise Limited Snapshot Imaging in the Presence of RFI with LOFAR's Initial Test Station (ITS)", SKA International Conference, Penticton (Canada), July 2004
  63. J.G. bij de Vaate, S.J. Wijnholds, J.D. Bregman, "Two Dimensional 256-Element Phased Array System for Radio Astronomy", 2003 Int. Symposium on Phased Array Systems and Technology, 14-17 October 2003, pp 359-364
  64. Stefan J. Wijnholds, A. Ger de Bruyn, Jaap D. Bregman, Jan-Geralt bij de Vaate, "Observational Results from THEA, a Step Towards SKA", Nederlands Astronomen Conferentie (NAC), Kleve (Germany), May 2003

Internal reports and memos

  1. M. Waterson et al., "Report on the station calibration task," SKA-TEL-SKO-0001088, rev. 1, 20 October 2019.
  2. S. J. Wijnholds, "Analysis of maximum tolerable levels for correlated spurious signals," ASTRON document no. 010801, 18 December 2018.
  3. Stefan J. Wijnholds et al., "TT-LOW RT23 Report: Findings on SDP-LOW calibration,", SKA-TEL-SKO-XXXXXXX, rev. C, 29 Nvoember 2017.
  4. "Ionospheric calibratability of LOFAR 2.0," ASTRON memo, 21 September 2017.
  5. P. E. Dewdney et al., "Beamformer and calibration report - SKA1-LOW," SKA-TEL-SKO-0000777, rev. 01, 27 June 2017.
  6. S. J. Wijnholds et al.,"Ionospheric calibratability of SKA1-low," SKA-TEL-SKO-0000755, rev. 01, 25 April 2017.
  7. "L1 and L2 stability requirements for SKA-low," SKA-TEL-LFAA-0200011, revision B, 9 June 2016.
  8. "Analysis of tied-array beamforming for ARTS," ASTRON-MEM-191, revision 2.1, 25 May 2016.
  9. S. J. Wijnholds et al., "SDP Memo: Feasibility analysis of baseline-dependent averaging," SKA-TEL-SDP-0000017-REP, revision 01C, 7 April 2016.
  10. S. J. Wijnholds and J. D. Bregman, "Configuration Considerations for the Inner Area of SKA-low," SKA-TEL-SKO-00000036-SE-TN, revision 01, 20 November 2015.
  11. R. Wayth, S. Wijnholds and A. Sutinjo, "AAVS1 Calibration Plan," SKA-TEL-LFAA-0200006, revision A, 12 August 2015.
  12. A. W. Gunst, A. Faulkner, S. J. Wijnholds, R. Jongerius and S. Torchinsky, "Architectural Design Document," SKA-TEL-MFAA-0200001-SE-ADD, revision A, 10 April 2015.
  13. Stefano Salvini and Stefan J. WIjnholds, "Scientific publication of the results of demonstrator of large parallel solvers for huge astronomical datasets," D10.12 Hilado project (RadioNet3), 28 February 2015.
  14. S. J. Wijnholds, S. Salvini, R. Dodson and P. Alexander, "PDR.01.04 Theoretical analysis of baseline-dependent averaging," SKA-TEL-SDP-0000017-SDP.ARCH, revision 1.0, 9 February 2015.
  15. Stefano Salvini, Stefan J. Wijnholds and Marzia Rivi, "Prototype software for the demonstration of the solvers on a variety of hardware platforms," D10.8, Hilado project (RadioNet3), 30 June 2014.
  16. J.A. Kegel, G.W. Kant and S.J. Wijnholds, "PAASAR: Phased Array Antenna for Search and Rescue - PAASAR Phased Array Calibration", AST-ESA-PAASAR-TN-002, 31 January 2014.
  17. Stefan J. Wijnholds, "Low Frequency Aperture Array - Substantiation of Level 1 Calibration Requirements", SKA-TEL.LFAA.SE.CAL-AADC-TN-001, 23 January 2014.
  18. Stefan J. Wijnholds, Keith J.B. Grainge and Ronald Nijboer, "Status Update on AA Calibration and Imaging Research", SKA Memo 145, October 2012.
  19. "LOFAR Configuration Considerations as a Design Exercise for SKA", SKA Memo 143, July 2012.
  20. J. P. Hamaker, S. J. Wijnholds and T. D. Carozzi, "Inventory of polarimetric transformations in the LOFAR signal path,", version 5, 2 December 2011.
  21. "Impact analysis of 4-bit quantization in LOFAR,", March 2011.
  22. Stefan J. Wijnholds and Jaap D. Bregman, "AA-lo Station Lay-out Aspects Illustrated by a Fractal Hexagonal Structure", Technical Report ASTRON-RP-468, February 2011.
  23. "Station Calibration Cookbook", Technical Report LOFAR-ASTRON-MAN-049, January 2011.
  24. "Overview of the Initial Production Version of the Station Calibration Pipeline", Technical Report LOFAR-ASTRON-MEM-263, January 2011.
  25. Stefan J. Wijnholds, Michiel A. Brentjens and Marchel Gerbers, "Impact of Water Puddles on HBA Tile Performance", Technical Report LOFAR-ASTRON-MEM-252, 6 September 2010.
  26. "Crosstalk in the LOFAR Station Backend", Technical Report LOFAR-ASTRON-RPT-253, September 2010
  27. "From an Electromagnetic Array Model to a Signal Processing Array Model", Technical Report ASTRON-TN-013, November 2008
  28. "Mutual Coupling, Inter-tile Spacing and Inter-station Rotation in the HBA Array", Technical Report LOFAR-ASTRON-MEM-245, August 2008
  29. "LBA station configuration", Technical Report LOFAR-ASTRON-MEM-241, December 2007
  30. "Imaging Demonstration with the Effelsberg Station", Technical Report LOFAR-ASTRON-RPT-141, November 2007
  31. "Matlab's Distributed Computing Toolbox Trial", Technical Report ASTRON-RP-272, October 2007
  32. "CS1 system validation", Technical Report LOFAR-ASTRON-RPT-124, April 2007
  33. Stefan J. Wijnholds, Jaap D. Bregman, "Design concept for a Lunar Low Frequency Array", Technical Report ASTRON-RP-160, April 2007
  34. "Station Calibration - Pitfalls & Possibilities 2006", Technical Report LOFAR-ASTRON-MEM-217, October 2006
  35. "A Spatial RFI Detection Method for LOFAR Stations", Technical Report LOFAR-ASTRON-MEM-181, July 2006
  36. "Study on LOFAR Core Calibratability Based on Source Statistics", Technical Report LOFAR-ASTRON-MEM-205, June 2006
  37. "Implications of Polarization Effects on Station Configuration and Signal Processing", Technical Report LOFAR-ASTRON-MEM-189, November 2005
  38. "Statistical Performance Analysis of Station Calibration Algorithms", Technical Report LOFAR-ASTRON-MEM-188, November 2005
  39. "Calibration Algorithms on the Local Control Unit", Technical Report LOFAR-ASTRON-MEM-171, September 2005
  40. "Station Calibration Methods", Technical Report LOFAR-ASTRON-MEM-093, September 2005
  41. "ITS Results 2005 - Filling the Gaps", Technical Report LOFAR-ASTRON-RPT-056, September 2005
  42. "Theory of Polarized Imaging With Phased Array Antennas", Technical Report LOFAR-ASTRON-MEM-183, July 2005
  43. "One year in the bushes - Results from ITS 2004", Technical Report LOFAR-ASTRON-RPT-052, February 2005
  44. "Theoretical analysis of the main lobe effects of beamsquint", Technical Report LOFAR-ASTRON-MEM-151, June 2004
  45. "Pre-correlation signal processing", Technical Report LOFAR-ASTRON-MEM-105, June 2004
  46. "THETA experimental results", Tehcnical Report LOFAR-ASTRON-MEM-120, March 2004
  47. "ITS experiments", Technical Report LOFAR-ASTRON-MEM-088, October 2003
  48. "General Description of the THEA Setup", Technical Report THEP-00678, March 2003
  49. "THEA Outdoor Calibration Using a Holographic Imaging Technique on a Celestial Source", Technical Report THEP-00668, February 2003
  50. "Study on Vector Modulator Behavior using an Outdoor Holographic Measurement Technique", Technical Report THEP-00669, February 2003


home

CV

publications