{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,1]],"date-time":"2025-11-01T09:33:21Z","timestamp":1761989601688,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2021,5,20]],"date-time":"2021-05-20T00:00:00Z","timestamp":1621468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Natural Science Foundation of China","award":["41774124"],"award-info":[{"award-number":["41774124"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The evaluation and inspection of steel bars in reinforced concrete structures are critical for prolonging the service life of buildings. In this regard, ground-penetrating radar (GPR) has been a crucial alternative due to its non-invasiveness and convenience. This paper reports the experimental activities on a test-site area inside a camp in Shanghai, China. To assess the concrete structures of the building, GPR was employed for the detection and localization of rebars in columns, beams, and floors. From the GPR B-scan profiles acquired using a high-frequency antenna, the exact quantity of reinforcements was identified according to the hyperbola responses. Considering the difficulty of inferring the exact position and the scale of the rebars, we applied reverse time migration (RTM) to collapse the hyperbolic response and retrieve the target in a migrated image. To verify the effectiveness of the RTM algorithm, we carried out an experiment on a concrete model with three reinforced bars. We also utilized the RTM algorithm to process the B-scan profiles collected in a column that was later excavated. The imaging results validated the capacity of RTM in localizing and shaping rebars. Then, we employed the RTM algorithm for the GPR B-scan data collected from the other column. Based on the imaging profile, the quantity and positions of the rebars were correctly determined. Moreover, the thickness of the protective layer was evaluated according to the migrated result. These results demonstrate that GPR combined with RTM could provide useful foundation data for structural evaluation.<\/jats:p>","DOI":"10.3390\/rs13102020","type":"journal-article","created":{"date-parts":[[2021,5,20]],"date-time":"2021-05-20T11:45:57Z","timestamp":1621511157000},"page":"2020","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Reverse-Time Migration Imaging of Ground-Penetrating Radar in NDT of Reinforced Concrete Structures"],"prefix":"10.3390","volume":"13","author":[{"given":"Ruiqing","family":"Shen","sequence":"first","affiliation":[{"name":"School of Ocean &amp; Earth Science, Tongji University, Shanghai 200092, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8120-6435","authenticated-orcid":false,"given":"Yonghui","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Ocean &amp; Earth Science, Tongji University, Shanghai 200092, China"}]},{"given":"Shufan","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Ocean &amp; Earth Science, Tongji University, Shanghai 200092, China"}]},{"given":"Bo","family":"Li","sequence":"additional","affiliation":[{"name":"School of Ocean &amp; Earth Science, Tongji University, Shanghai 200092, China"}]},{"given":"Wenda","family":"Bi","sequence":"additional","affiliation":[{"name":"School of Ocean &amp; Earth Science, Tongji University, Shanghai 200092, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2555","DOI":"10.1109\/TGRS.2004.834800","article-title":"Modeling of ground-penetrating Radar for accurate characterization of subsurface electric properties","volume":"42","author":"Lambot","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/j.jhydrol.2004.10.014","article-title":"Soil moisture content estimation using ground-penetrating radar reflection data","volume":"307","author":"Lunt","year":"2005","journal-title":"J. Hydrol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.jappgeo.2013.02.017","article-title":"Recent developments in the direct-current geoelectrical imaging method","volume":"95","author":"Loke","year":"2013","journal-title":"J. Appl. Geophys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1231","DOI":"10.1109\/36.927446","article-title":"Landmine detection with ground penetrating radar using hidden Markov models","volume":"39","author":"Gader","year":"2001","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1539","DOI":"10.1109\/TGRS.2013.2252016","article-title":"Histograms of Oriented Gradients for Landmine Detection in Ground-Penetrating Radar Data","volume":"52","author":"Torrione","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2560","DOI":"10.1109\/TGRS.2007.900993","article-title":"A Large-Scale Systematic Evaluation of Algorithms Using Ground-Penetrating Radar for Landmine Detection and Discrimination","volume":"45","author":"Wilson","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1190\/1.1444925","article-title":"The use of geophysical prospecting for imaging active faults in the Roer Graben, Belgium","volume":"66","author":"Demanet","year":"2001","journal-title":"Geophysics"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1758","DOI":"10.1190\/1.1444276","article-title":"Ground-penetrating radar velocity tomography in heterogeneous and anisotropic media","volume":"62","author":"Vasco","year":"1997","journal-title":"Geophysics"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"12783","DOI":"10.1029\/2019GL084458","article-title":"Comparison of dielectric properties and structure of lunar regolith at Chang\u2019e-3 and Chang\u2019e-4 landing sites revealed by ground-penetrating radar","volume":"46","author":"Lai","year":"2019","journal-title":"Geophys. Res. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1109\/JSTARS.2017.2786476","article-title":"Simulation of the Lunar Regolith and Lunar-Penetrating Radar Data Processing","volume":"11","author":"Zhang","year":"2018","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/S0926-9851(00)00021-5","article-title":"Evaluation of GPR techniques for civil-engineering applications: Study on a test site","volume":"45","author":"Grandjean","year":"2000","journal-title":"J. Appl. Geophys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.ndteint.2017.04.002","article-title":"A review of Ground Penetrating Radar application in civil engineering: A 30-year journey from Locating and Testing to Imaging and Diagnosis","volume":"96","author":"Lai","year":"2018","journal-title":"NDT E Int."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/S0950-0618(02)00015-6","article-title":"Concrete bridge inspection with a mobile GPR system","volume":"16","author":"Hugenschmidt","year":"2002","journal-title":"Constr. Build. Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"411","DOI":"10.3151\/jact.10.411","article-title":"Ground Penetrating Radar: An Application to Estimate Volumetric Water Content and Reinforced Bar Diameter in Concrete Structures","volume":"10","author":"Leucci","year":"2012","journal-title":"J. Adv. Concr. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1007\/s10712-019-09565-5","article-title":"Using Ground Penetrating Radar Methods to Investigate Reinforced Concrete Structures","volume":"41","author":"Tosti","year":"2020","journal-title":"Surv. Geophys."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Zhou, F., Chen, Z.C., Liu, H., Cui, J., Spencer, B.E., and Fang, G.Y. (2018). Simultaneous Estimation of Rebar Diameter and Cover Thickness by a GPR-EMI Dual Sensor. Sensors, 18.","DOI":"10.3390\/s18092969"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1016\/j.conbuildmat.2008.05.018","article-title":"Measurement radius of reinforcing steel bar in concrete using digital image GPR","volume":"23","author":"Chang","year":"2009","journal-title":"Constr. Build. Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1784\/insi.45.12.813.52980","article-title":"Assessing bar size of steel reinforcement in concrete using ground penetrating radar and neural networks","volume":"45","author":"Shaw","year":"2003","journal-title":"Insight Non Destruct. Test. Cond. Monit."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Tesic, K., Baricevic, A., and Serdar, M. (2021). Non-Destructive Corrosion Inspection of Reinforced Concrete Using Ground-Penetrating Radar: A Review. Materials, 14.","DOI":"10.3390\/ma14040975"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1016\/j.conbuildmat.2012.05.026","article-title":"Condition assessment of concrete structures using a new analysis method: Ground-penetrating radar computer-assisted visual interpretation","volume":"38","author":"Tarussov","year":"2013","journal-title":"Constr. Build. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"103279","DOI":"10.1016\/j.autcon.2020.103279","article-title":"Detection and localization of rebar in concrete by deep learning using ground penetrating radar","volume":"118","author":"Liu","year":"2020","journal-title":"Autom. Constr."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1109\/LGRS.2020.2977505","article-title":"A Machine Learning Scheme for Estimating the Diameter of Reinforcing Bars Using Ground Penetrating Radar","volume":"18","author":"Giannakis","year":"2021","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Zadhouse, H., Giannopoulos, A., and Giannakis, I. (2021). Optimising the Complex Refractive Index Model for Estimating the Permittivity of Heterogeneous Concrete Models. Remote Sens., 13.","DOI":"10.5194\/egusphere-egu21-16517"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.ndteint.2013.03.003","article-title":"Full-waveform GPR inversion to assess chloride gradients in concrete","volume":"57","author":"Kalogeropoulos","year":"2013","journal-title":"NDT E Int."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"102294","DOI":"10.1016\/j.ndteint.2020.102294","article-title":"Reverse-time migration for evaluating the internal structure of tree-trunks using ground-penetrating radar","volume":"115","author":"Alani","year":"2020","journal-title":"NDT E Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"280738","DOI":"10.1155\/2014\/280738","article-title":"A Review on Migration Methods in B-Scan Ground Penetrating Radar Imaging","volume":"2014","author":"Ozdemir","year":"2014","journal-title":"Math. Probl. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1046\/j.1365-2478.1998.00091.x","article-title":"Frequency\u2013wavenumber modelling and migration of 2D GPR data in moderately heterogeneous dispersive Media","volume":"46","author":"Bitri","year":"1998","journal-title":"Geophys. Prospect."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/S0926-9851(99)00065-8","article-title":"Multidimensional GPR array processing using Kirchhoff migration","volume":"43","author":"Moran","year":"2000","journal-title":"J. Appl. Geophys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"791","DOI":"10.1007\/s12583-015-0596-x","article-title":"Reverse-time prestack depth migration of GPR data from topography for amplitude reconstruction in complex environments","volume":"26","author":"Bradford","year":"2015","journal-title":"J. Earth Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1190\/1.1443271","article-title":"Examples of reverse-time migration of single-channel, ground-penetrating radar profiles","volume":"57","author":"Fisher","year":"1992","journal-title":"Geophysics"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1109\/TGRS.2004.839920","article-title":"Migration velocity analysis and prestack migration of common-transmitter GPR data","volume":"43","author":"Zhou","year":"2005","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jappgeo.2014.05.008","article-title":"Application of pre-stack reverse time migration based on FWI velocity estimation to ground penetrating radar data","volume":"107","author":"Liu","year":"2014","journal-title":"J. Appl. Geophys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2957","DOI":"10.1109\/JSTARS.2018.2841361","article-title":"Frequency-Domain Reverse-Time Migration of Ground Penetrating Radar Based on Layered Medium Green\u2019s Functions","volume":"11","author":"Liu","year":"2018","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"7221","DOI":"10.1109\/TGRS.2019.2912318","article-title":"Energy Flow Domain Reverse-Time Migration for Borehole Radar","volume":"57","author":"Huo","year":"2019","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1247","DOI":"10.1016\/j.cageo.2005.11.006","article-title":"Numerical modeling of ground-penetrating radar in 2-D using MATLAB","volume":"32","author":"Irving","year":"2006","journal-title":"Comput. Geosci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/10\/2020\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:04:54Z","timestamp":1760162694000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/10\/2020"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,20]]},"references-count":35,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["rs13102020"],"URL":"https:\/\/doi.org\/10.3390\/rs13102020","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,5,20]]}}}