{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:42:52Z","timestamp":1760150572146,"version":"build-2065373602"},"reference-count":17,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2023,11,30]],"date-time":"2023-11-30T00:00:00Z","timestamp":1701302400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NATO-SPS","award":["G5395"],"award-info":[{"award-number":["G5395"]}]},{"name":"French SGDSN","award":["G5395"],"award-info":[{"award-number":["G5395"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>DEXTER (detection of explosives and firearms to counter terrorism) is a project funded by NATO\u2019s Science for Peace and Security (SPS) program with the goal of developing an integrated system capable of remotely and accurately detecting explosives and firearms in public places without impeding the flow of pedestrians. While body scanner systems in secure areas of public places are becoming more and more efficient, the attack at Brussels airport on 22 March 2016, upstream of these systems, in the middle of the crowd of passengers, demonstrated the lack of discreet and real-time security against threats of mass terrorism. The NATO-SPS international and multi-year DEXTER project aims to provide new technical and strategic solutions to fill this gap. This project is based on multi-sensor coordination and fusion, from hyperspectral remote laser to smart glasses, artificial algorithms, and suspect identification and tracking. One of these sensors is dedicated to threat detection (large weapon or explosive belt) using the clothing of pedestrians by means of an active microwave component. This project is referred to as MIC (Microwave Imaging Curtain), also supported by the French SGDSN (General Secretariat of Defense and National Security), and utilizes a radar system capable of generating 3D images in real-time to address non-checkpoint detection of explosives and firearms. The project, led by ONERA (France), is based on a radar imaging system developed by the Fraunhofer FHR institute, using a MIMO architecture with an Ultra-Wide Band waveform. Although high-resolution 3D microwave imaging is already being used in expensive body scanners to detect firearms concealed under clothing, MIC\u2019s innovative approach lies in utilizing a high-resolution 3D imaging device that can detect larger dangerous objects carried by moving individuals at a longer range, in addition to providing discrete detection in pedestrian flow. Automatic detection and classification of these dangerous objects is carried out on 3D radar images using a deep-learning network. This paper will outline the project\u2019s objectives and constraints, as well as the design, architecture, and performance of the final system. Additionally, it will present real-time imaging results obtained during a live demonstration in a relevant environment.<\/jats:p>","DOI":"10.3390\/s23239531","type":"journal-article","created":{"date-parts":[[2023,11,30]],"date-time":"2023-11-30T09:39:12Z","timestamp":1701337152000},"page":"9531","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["MIC: Microwave Imaging Curtain for Dynamic and Automatic Detection of Weapons and Explosive Belts"],"prefix":"10.3390","volume":"23","author":[{"given":"R\u00e9mi","family":"Baqu\u00e9","sequence":"first","affiliation":[{"name":"ONERA\/DEMR, F-13661 Salon de Provence, France"}]},{"given":"Luc","family":"Vignaud","sequence":"additional","affiliation":[{"name":"ONERA\/DEMR, Universit\u00e9 de Paris-Saclay F-91123 Palaiseau, France"}]},{"given":"Valentine","family":"Wasik","sequence":"additional","affiliation":[{"name":"ONERA\/DEMR, Universit\u00e9 de Toulouse, F-31055 Toulouse, France"}]},{"given":"Nicolas","family":"Castet","sequence":"additional","affiliation":[{"name":"ONERA\/DEMR, F-13661 Salon de Provence, France"}]},{"given":"Reinhold","family":"Herschel","sequence":"additional","affiliation":[{"name":"Fraunhofer FHR, D-53343 Wachtberg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5788-2986","authenticated-orcid":false,"given":"Harun","family":"Cetinkaya","sequence":"additional","affiliation":[{"name":"Institute of Integrated Systems, Ruhr-Universit\u00e4t Bochum, D-44780 Bochum, Germany"}]},{"given":"Thomas","family":"Brandes","sequence":"additional","affiliation":[{"name":"Fraunhofer SCAI, D-53757 Sankt Augustin, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,30]]},"reference":[{"key":"ref_1","first-page":"65","article-title":"Wide-bandwidth, wide-beamwidth, high-resolution, millimeter-wave imaging for concealed weapon detection","volume":"Volume 8715","author":"Sheen","year":"2013","journal-title":"Passive and Active Millimeter-Wave Imaging XVI"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1117\/12.606825","article-title":"Circularly polarized millimeter-wave imaging for personnel screening","volume":"Volume 5789","author":"Sheen","year":"2005","journal-title":"Passive Millimeter-Wave Imaging Technology VIII"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1109\/TGRS.2010.2053038","article-title":"A sparse aperture mimo-sar-based uwb imaging system for concealed weapon detection","volume":"49","author":"Zhuge","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","first-page":"458","article-title":"UWB 3D near-field imaging with a sparse MIMO antenna array for concealed weapon detection","volume":"Volume 10633","author":"Ranney","year":"2018","journal-title":"Radar Sensor Technology XXII"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3567","DOI":"10.1109\/TMTT.2011.2172812","article-title":"A novel fully electronic active real-time imager based on a planar multistatic sparse array","volume":"59","author":"Ahmed","year":"2011","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1117\/12.243191","article-title":"Concealed explosive detection on personnel using a wideband holographic millimeter-wave imaging system","volume":"Volume 2755","author":"Kadar","year":"1996","journal-title":"Signal Processing, Sensor Fusion, and Target Recognition V"},{"key":"ref_7","unstructured":"(2023, November 13). Available online: https:\/\/vayyar.com\/public-safety\/."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1109\/MSP.2007.904812","article-title":"Mimo radar with colocated antennas","volume":"24","author":"Li","year":"2007","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_9","unstructured":"Genghammer, A., Juenemann, R., Ahmed, S., and Gumbmann, F. (2020). Calibration Device and Calibration Method for Calibrating Antenna Arrays. (US 10,527,714 B2), U.S. Patent."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"052104","DOI":"10.1088\/1757-899X\/677\/5\/052104","article-title":"Research on sidelobe suppression method in LFM pulse compression technique","volume":"677","author":"Wang","year":"2019","journal-title":"IOP Conf. Series Mater. Sci. Eng."},{"key":"ref_11","unstructured":"Ahmed, S. (2015). Electronic Microwave Imaging with Planar Multistatic Arrays. [Ph.D. Thesis, University Erlangen]."},{"key":"ref_12","unstructured":"(1999). Council Recommendation of 12 July 1999 on the Limitation of Exposure of the General Public to Electromagnetic Fields (0 Hz to 300 GHz) (Standard No. 1999\/519\/EC)."},{"key":"ref_13","unstructured":"Ciresan, D.C., Meier, U., Masci, J., Gambardella, L.M., and Schmidhuber, J. (2011, January 16\u201322). Flexible, High Performance Convolutional Neural Networks for Image Classification. Proceedings of the Twenty-Second International Joint Conference on Artificial Intelligence, Barcelona, Spain."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1038\/nature14539","article-title":"Deep learning","volume":"521","author":"LeCun","year":"2015","journal-title":"Nature"},{"key":"ref_15","first-page":"9","article-title":"Explainable AI: A Brief History of the Concept","volume":"134","year":"2023","journal-title":"ERCIM News"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Ribeiro, M.T., Singh, S., and Guestrin, C. (2016, January 13\u201317). \u201cWhy should I trust you?\u201d Explaining the predictions of any classifier. Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, San Francisco, CA, USA.","DOI":"10.1145\/2939672.2939778"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Selvaraju, R.R., Cogswell, M., Das, A., Vedantam, R., Parikh, D., and Batra, D. (2017, January 22\u201329). Grad-cam: Visual explanations from deep networks via gradient-based localization. Proceedings of the IEEE International Conference on Computer Vision, Venice, Italy.","DOI":"10.1109\/ICCV.2017.74"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/23\/9531\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:34:57Z","timestamp":1760132097000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/23\/9531"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,30]]},"references-count":17,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["s23239531"],"URL":"https:\/\/doi.org\/10.3390\/s23239531","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2023,11,30]]}}}