{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T04:22:13Z","timestamp":1769746933271,"version":"3.49.0"},"reference-count":30,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,2,23]],"date-time":"2021-02-23T00:00:00Z","timestamp":1614038400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This paper presents the results of investigations on the beamforming of a low-frequency radio-telescope LOFAR which can be used as a receiver in passive coherent location (PCL) radars for aerial and space object detection and tracking. The use of a LOFAR radio-telescope for the passive tracking of space objects can be a highly cost-effective solution due to the fact that most of the necessary equipment needed for passive radiolocation already exists in the form of LOFAR stations. The capability of the radiolocation of planes by a single LOFAR station in Borowiec is considered to be \u2018proof of concept\u2019 for future research focused on the localization of space objects. Beam patterns of single sets of LOFAR antennas (known as tiles), as well as for the entire LOFAR station, are presented and thoroughly discussed in the paper. Issues related to grating lobes in LOFAR beam patterns are also highlighted. A beamforming algorithm used for passive radiolocation purposes, exploiting data collected by a LOFAR station, is also discussed. The results of preliminary experiments carried out with real signals collected by the LOFAR station in Borowiec, Poland confirm that the appropriate beamforming can significantly increase the radar\u2019s detection range, as well as the detection\u2019s certainty.<\/jats:p>","DOI":"10.3390\/rs13040810","type":"journal-article","created":{"date-parts":[[2021,2,23]],"date-time":"2021-02-23T20:19:36Z","timestamp":1614111576000},"page":"810","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Beamforming of LOFAR Radio-Telescope for Passive Radiolocation Purposes"],"prefix":"10.3390","volume":"13","author":[{"given":"Aleksander","family":"Droszcz","sequence":"first","affiliation":[{"name":"Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska 15\/19, 00-665 Warsaw, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4303-9450","authenticated-orcid":false,"given":"Konrad","family":"J\u0119drzejewski","sequence":"additional","affiliation":[{"name":"Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska 15\/19, 00-665 Warsaw, Poland"}]},{"given":"Julia","family":"K\u0142os","sequence":"additional","affiliation":[{"name":"Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska 15\/19, 00-665 Warsaw, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5357-142X","authenticated-orcid":false,"given":"Krzysztof","family":"Kulpa","sequence":"additional","affiliation":[{"name":"Institute of Electronic Systems, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska 15\/19, 00-665 Warsaw, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6467-7091","authenticated-orcid":false,"given":"Mariusz","family":"Po\u017coga","sequence":"additional","affiliation":[{"name":"Space Research Centre of Polish Academy of Sciences, Bartycka Str. 18A, 00-716 Warsaw, Poland"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Heald, G., McKean, J., and Pizzo, R. (2018). Low Frequency Radio Astronomy and the LOFAR Observatory, Lectures from the Third LOFAR Data Processing School Editors, Springer.","DOI":"10.1007\/978-3-319-23434-2"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1515\/acgeo-2016-0028","article-title":"Prospects for solar and space weather research with polish part of the LOFAR telescope","volume":"64","author":"Krankowski","year":"2016","journal-title":"Acta Geophys."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Droszcz, A., K\u0142os, J., J\u0119drzejewski, K., Kulpa, K., and Po\u017coga, M. (2020, January 5\u20138). Beamforming of LOFAR radio telescope antennas used as sensors in passive radiolocation system. Proceedings of the 2020 21st International Radar Symposium (IRS), Warsaw, Poland.","DOI":"10.23919\/IRS48640.2020.9253779"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"K\u0142os, J., Droszcz, A., J\u0119drzejewski, K., Kulpa, K., and Po\u017coga, M. (2020, January 5\u20138). On the possibility of using LOFAR radio telescope for passive radiolocation. Proceedings of the 2020 21st International Radar Symposium (IRS), Warsaw, Poland.","DOI":"10.23919\/IRS48640.2020.9253840"},{"key":"ref_5","unstructured":"Virtanen, I.I. (2020, October 25). Station Data Cookbook. Available online: https:\/\/lofar.ie\/wp-content\/uploads\/2018\/03\/station_data_cookbook_v1.2.pdf."},{"key":"ref_6","unstructured":"Griffiths, H. (2004). Bistatic and Multistatic Radar, IEE Military Radar Seminar."},{"key":"ref_7","unstructured":"Griffiths, H., and Baker, C. (2017). An Introduction to Passive Radar, Artech House radar library, Artech House."},{"key":"ref_8","unstructured":"Malanowski, M. (2019). Signal Processing for Passive Bistatic Radar, Artech House radar library, Artech House."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Richards, M.A., Scheer, J., Holm, W.A., and Melvin, W.L. (2010). Principles of Modern Radar, Scitech Publishing.","DOI":"10.1049\/SBRA021E"},{"key":"ref_10","unstructured":"(2020, October 25). WorldDAB Global Summary. Available online: https:\/\/www.worlddab.org\/public_document\/file\/916\/Global_Summary_30.08.17.pdf."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"548","DOI":"10.1109\/TASSP.1984.1164359","article-title":"A comparison of efficient beamforming algorithms","volume":"32","author":"Mucci","year":"1984","journal-title":"IEEE Trans. Acoust. Speech Signal Process."},{"key":"ref_12","unstructured":"Zimmerman, N. (2020, October 25). Analysis of LOFAR High Band Antenna Design. Available online: https:\/\/www.haystack.mit.edu\/edu\/reu\/2003\/files\/neil\/neil.pdf."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Van Trees, H. (2002). Optimum Array Processing: Part IV of Detection, Estimation, and Modulation Theory, John Wiley and Sons.","DOI":"10.1002\/0471221104"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1109\/TAES.2012.6129656","article-title":"Two Methods for Target Localization in Multistatic Passive Radar","volume":"48","author":"Malanowski","year":"2012","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_15","unstructured":"Malanowski, M., Kulpa, K., and Suchozebrski, R. (2009, January 6\u20139). Two-stage tracking algorithm for passive radar. Proceedings of the 2009 12th International Conference on Information Fusion, Seatle, WA, USA."},{"key":"ref_16","unstructured":"Wielgo, M., Rzewuski, S., Misiurewicz, J., Kurowska, A., and Malanowski, M. (2015, January 6\u20139). Multistatic tracking experiment with a WiFiRAD passive radar. Proceedings of the 2015 18th International Conference on Information Fusion (Fusion), Washington, DC, USA."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Cao, D., Li, T., Kang, P., Liu, H., Zhou, S., and Su, H. (2016, January 10\u201313). Single-pulse multi-beams operation of phased array radar. Proceedings of the 2016 CIE International Conference on Radar (RADAR), Guangzhou, China.","DOI":"10.1109\/RADAR.2016.8059597"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Tonnaer, A. (2013, January 9\u201312). Dual axis multi-beam radars. Proceedings of the 2013 International Conference on Radar, Adelaide, SA, Australia.","DOI":"10.1109\/RADAR.2013.6652024"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Cox, P.B., and van Rossum, W.L. (May, January 27). Analysing Multibeam, Cooperative, Ground Based Radar in a Bistatic Configuration. Proceedings of the 2020 IEEE International Radar Conference (RADAR), Washington, DC, USA.","DOI":"10.1109\/RADAR42522.2020.9114620"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Malanowski, M., Kulpa, K.S., Samczynski, P., Misiurewicz, J., and Kulpa, J. (2012, January 22\u201325). Long range FM-based passive radar. Proceedings of the IET International Conference on Radar Systems (Radar 2012), Glasgow, UK.","DOI":"10.1049\/cp.2012.1578"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Kulpa, K.S., and Misiurewicz, J. (2006, January 16\u201319). Stretch Processing for Long Integration Time Passive Covert Radar. Proceedings of the 2006 CIE International Conference on Radar, Shanghai, China.","DOI":"10.1109\/ICR.2006.343481"},{"key":"ref_22","unstructured":"(2020, January 21). Flightradar24. Available online: https:\/\/www.flightradar24.com."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Malanowski, M., and Kulpa, K. (2018, January 23\u201327). Correction of range cell migration with FIR filter for passive radar. Proceedings of the 2018 IEEE Radar Conference (RadarConf18), Oklahoma City, OK, USA.","DOI":"10.1109\/RADAR.2018.8378719"},{"key":"ref_24","unstructured":"Kulpa, K. (2004, January 17-21). Adaptive clutter rejection in bi-static CW radar. Proceedings of the 2004 International Radar Symposium, Warsaw, Poland."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Malanowski, M. (2006, January 24\u201326). Comparison of adaptive methods for clutter removal in PCL radar. Proceedings of the 2006 International Radar Symposium, Krakow, Poland.","DOI":"10.1109\/IRS.2006.4338044"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kulpa, K. (2006, January 24\u201326). Simple sea clutter canceller for noise radar. Proceedings of the International Radar Symposium, Krakow, Poland.","DOI":"10.1109\/IRS.2006.4338058"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kulpa, K. (2008, January 22\u201324). The CLEAN type algorithms for radar signal processing. Proceedings of the 2008 Microwaves, Radar and Remote Sensing Symposium, Kiev, Ukraine.","DOI":"10.1109\/MRRS.2008.4669567"},{"key":"ref_28","unstructured":"Kulpa, K. (2013). Signal Processing in Noise Waveform Radar, Artech House radar library, Artech House."},{"key":"ref_29","first-page":"693733","article-title":"Resampling methods for stretch processing in PCL radars. Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments 2007","volume":"6937","author":"Misiurewicz","year":"2007","journal-title":"Int. Soc. Opt. Photonics"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1049\/ip-rsn:20045026","article-title":"Masking effect and its removal in PCL radar","volume":"152","author":"Kulpa","year":"2005","journal-title":"IEE Proc. Radar Sonar Navig."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/4\/810\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:26:58Z","timestamp":1760160418000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/4\/810"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,23]]},"references-count":30,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["rs13040810"],"URL":"https:\/\/doi.org\/10.3390\/rs13040810","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,23]]}}}