{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T13:42:00Z","timestamp":1772804520832,"version":"3.50.1"},"reference-count":39,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,8]],"date-time":"2019-05-08T00:00:00Z","timestamp":1557273600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Ministry of Economy and Innovation (MINECO) and European Union FEDER","award":["project FIS2015-65998-C2-1 and FIS2015-65998-C2- 2"],"award-info":[{"award-number":["project FIS2015-65998-C2-1 and FIS2015-65998-C2- 2"]}]},{"name":"Conseller\u00eda de Educaci\u00f3n, Investigaci\u00f3n, Cultura y Deporte de la Generalitat Valenciana","award":["project AICO\/2016\/060"],"award-info":[{"award-number":["project AICO\/2016\/060"]}]},{"name":"US Army Research, Development and Engineering Command (RDECOM)","award":["W911NF-16-1-0563"],"award-info":[{"award-number":["W911NF-16-1-0563"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Nondestructive testing of metallic objects that may contain embedded defects of different sizes is an important application in many industrial branches for quality control. Most of these techniques allow defect detection and its approximate localization, but few methods give enough information for its 3D reconstruction. Here we present a hybrid laser\u2013transducer system that combines remote, laser-generated ultrasound excitation and noncontact ultrasonic transducer detection. This fully noncontact method allows access to scan areas on different object\u2019s faces and defect details from different angles\/perspectives. This hybrid system can analyze the object\u2019s volume data and allows a 3D reconstruction image of the embedded defects. As a novelty for signal processing improvement, we use a 2D apodization window filtering technique, applied along with the synthetic aperture focusing algorithm, to remove the undesired effects due to side lobes and wide-angle reflections of propagating ultrasound waves, thus enhancing the resulting 3D image of the defect. Finally, we provide both qualitative and quantitative volumetric results that yield valuable information about defect location and size.<\/jats:p>","DOI":"10.3390\/s19092138","type":"journal-article","created":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T11:22:35Z","timestamp":1557400955000},"page":"2138","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Fully Noncontact Hybrid NDT for 3D Defect Reconstruction Using SAFT Algorithm and 2D Apodization Window"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2553-8205","authenticated-orcid":false,"given":"Hossam","family":"Selim","sequence":"first","affiliation":[{"name":"Physics Department, Universitat Polit\u00e8cnica de Catalunya, Rambla Sant Nebridi 22, 08222 Terrassa, Barcelona, Spain"}]},{"given":"Jos\u00e9","family":"Trull","sequence":"additional","affiliation":[{"name":"Physics Department, Universitat Polit\u00e8cnica de Catalunya, Rambla Sant Nebridi 22, 08222 Terrassa, Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9282-838X","authenticated-orcid":false,"given":"Miguel","family":"Delgado Prieto","sequence":"additional","affiliation":[{"name":"Electronic Engineering Department, Universitat Polit\u00e8cnica de Catalunya, Rambla Sant Nebridi 22, 08222 Terrassa, Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3537-9658","authenticated-orcid":false,"given":"Rub\u00e9n","family":"Pic\u00f3","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n para la Gesti\u00f3n Integrada de Zonas Costeras, Universitat Polit\u00e8cnica de Val\u00e8ncia, Paranimf 1, Grao de Gandia, 46730 Val\u00e8ncia, Spain"}]},{"given":"Luis","family":"Romeral","sequence":"additional","affiliation":[{"name":"Electronic Engineering Department, Universitat Polit\u00e8cnica de Catalunya, Rambla Sant Nebridi 22, 08222 Terrassa, Barcelona, Spain"}]},{"given":"Crina","family":"Cojocaru","sequence":"additional","affiliation":[{"name":"Physics Department, Universitat Polit\u00e8cnica de Catalunya, Rambla Sant Nebridi 22, 08222 Terrassa, Barcelona, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"17146","DOI":"10.3390\/s140917146","article-title":"Non-destructive evaluation of depth of surface cracks using ultrasonic frequency analysis","volume":"14","author":"Her","year":"2014","journal-title":"Sensors"},{"key":"ref_2","unstructured":"Rose, J.L. 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