{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T16:01:01Z","timestamp":1776182461030,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,9,7]],"date-time":"2024-09-07T00:00:00Z","timestamp":1725667200000},"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>Interferometric radars are widely used sensors for structural health monitoring. They are able to perform dynamic measurements of displacement with sub-millimeter precision. Today, the Ku-band is the most common, due to the spread of commercial systems operating in this band. At the same time, the W-band sensors are gaining ever more interest. Other popular systems work in the X-band. Since the characteristics of the measurements dramatically depend on the operative frequency, it is essential to highlight their differences. For instance, higher frequency allows for high displacement resolution, but it is more subject to phase wrapping and decorrelation effects. In this paper, a direct comparison between radars operating in X, Ku, and W-band for bridge monitoring is carried out. The radars provide frequency-modulated continuous-wave signals. Experimental campaigns were performed both in controlled and realistic scenarios (a stayed bridge). The results of the experiments demonstrate that all the three sensors are suitable for performing dynamic structure monitoring despite their differences. It is worth noting that this comparative analysis has highlighted the role of amplitude variation in phase\/displacement measurement. Regarding this point, the three different bands exhibit significant differences.<\/jats:p>","DOI":"10.3390\/rs16173323","type":"journal-article","created":{"date-parts":[[2024,9,9]],"date-time":"2024-09-09T04:15:01Z","timestamp":1725855301000},"page":"3323","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Interferometric Radars for Bridge Monitoring: Comparison among X-Bands, Ku-Bands, and W-Bands"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0822-8689","authenticated-orcid":false,"given":"Alessandra","family":"Beni","sequence":"first","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7285-4588","authenticated-orcid":false,"given":"Lapo","family":"Miccinesi","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3079-2777","authenticated-orcid":false,"given":"Lorenzo","family":"Pagnini","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-3005-0010","authenticated-orcid":false,"given":"Andrea","family":"Cioncolini","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]},{"given":"Jingfeng","family":"Shan","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3661-726X","authenticated-orcid":false,"given":"Massimiliano","family":"Pieraccini","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e2733","DOI":"10.1002\/stc.2733","article-title":"Bridge displacement estimation by fusing accelerometer and strain gauge measurements","volume":"28","author":"Ma","year":"2021","journal-title":"Struct. Control Health Monit."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8204","DOI":"10.1109\/JSEN.2021.3051697","article-title":"Estimation of Displacement Response in Steel Plate Girder Bridge Using a Single MEMS Accelerometer","volume":"21","author":"Morichika","year":"2021","journal-title":"IEEE Sens. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1212","DOI":"10.1016\/j.prostr.2023.01.156","article-title":"Capacitive accelerometers at low frequency for infrastructure monitoring","volume":"44","author":"Mazzei","year":"2023","journal-title":"Procedia Struct. Integr."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Wu, S., Zhang, B., Ding, X., Zhang, L., Zhang, Z., and Zhang, Z. (2023). Radar Interferometry for Urban Infrastructure Stability Monitoring: From Techniques to Applications. Sustainability, 15.","DOI":"10.3390\/su151914654"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.ndteint.2006.10.007","article-title":"Static and dynamic testing of bridges through microwave interferometry","volume":"40","author":"Pieraccini","year":"2007","journal-title":"NDT E Int."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1016\/j.isprsjprs.2018.02.020","article-title":"Dynamic displacement monitoring of long-span bridges with a microwave radar interferometer","volume":"138","author":"Zhang","year":"2018","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.ndteint.2007.11.002","article-title":"Interferometric radar vs. accelerometer for dynamic monitoring of large structures: An experimental comparison","volume":"41","author":"Pieraccini","year":"2008","journal-title":"NDT E Int."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3545","DOI":"10.1080\/014311600750037561","article-title":"Remote monitoring of buildings using a ground-based SAR: Application to cultural heritage survey","volume":"21","author":"Tarchi","year":"2000","journal-title":"Int. J. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Michel, C., and Keller, S. (2021). Advancing Ground-Based Radar Processing for Bridge Infrastructure Monitoring. Sensors, 21.","DOI":"10.3390\/s21062172"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Zou, L., Feng, W., Masci, O., Nico, G., Alani, A.M., and Sato, M. (2024). Bridge Monitoring Strategies for Sustainable Development with Microwave Radar Interferometry. Sustainability, 16.","DOI":"10.3390\/su16072607"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Pagnini, L., Miccinesi, L., Beni, A., and Pieraccini, M. (2024). Transversal Displacement Detection of an Arched Bridge with a Multimonostatic Multiple-Input Multiple-Output Radar. Sensors, 24.","DOI":"10.3390\/s24061839"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"210339","DOI":"10.1109\/ACCESS.2020.3039381","article-title":"Bridge Monitoring by a Monostatic\/Bistatic Interferometric Radar Able to Retrieve the Dynamic 3D Displacement Vector","volume":"8","author":"Miccinesi","year":"2020","journal-title":"IEEE Access"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Miccinesi, L., Beni, A., and Pieraccini, M. (2021). Multi-Monostatic Interferometric Radar for Bridge Monitoring. Electronics, 10.","DOI":"10.3390\/electronics10030247"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Miccinesi, L., Pieraccini, M., Beni, A., Andries, O., and Consumi, T. (2021). Multi-Monostatic Interferometric Radar with Radar Link for Bridge Monitoring. Electronics, 10.","DOI":"10.3390\/electronics10222777"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2960","DOI":"10.1109\/TIM.2023.3292960","article-title":"FMCW Radar for Noncontact Bridge Structure Displacement Estimation","volume":"72","author":"Pramudita","year":"2023","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Pieraccini, M., and Miccinesi, L. (2019). Ground-Based Radar Interferometry: A Bibliographic Review. Remote Sens., 11.","DOI":"10.3390\/rs11091029"},{"key":"ref_17","first-page":"101949","article-title":"Detecting the slope movement after the 2018 Baige Landslides based on ground-based and space-borne radar observations","volume":"84","author":"Li","year":"2020","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Liu, B., Ge, D., Li, M., Zhang, L., Wang, Y., and Zhang, X. (2016, January 10\u201315). Using GB-SAR technique to monitor displacement of open pit slope. Proceedings of the 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China.","DOI":"10.1109\/IGARSS.2016.7730564"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.engstruct.2018.02.084","article-title":"Determining dynamic characteristics of high rise buildings using interferometric radar system","volume":"164","author":"Sofi","year":"2018","journal-title":"Eng. Struct."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Luzi, G., Crosetto, M., and Fern\u00e1ndez, E. (2017). Radar Interferometry for Monitoring the Vibration Characteristics of Buildings and Civil Structures: Recent Case Studies in Spain. Sensors, 17.","DOI":"10.3390\/s17040669"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Jung, J., Kim, D., Vadivel, S.K.P., and Yun, S.-H. (2019). Long-Term Deflection Monitoring for Bridges Using X and C-Band Time-Series SAR Interferometry. Remote Sens., 11.","DOI":"10.3390\/rs11111258"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1109\/JSTARS.2016.2587778","article-title":"Bridge Displacements Monitoring Using Space-Borne X-Band SAR Interferometry","volume":"10","author":"Lazecky","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"975","DOI":"10.1109\/JSTARS.2016.2640316","article-title":"A Compact Ground-Based Interferometric Radar for Landslide Monitoring: The Xer\u00e9m Experiment","volume":"10","author":"Ramos","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Michelini, A., Coppi, F., Bicci, A., and Alli, G. (2019). SPARX, a MIMO Array for Ground-Based Radar Interferometry. Sensors, 19.","DOI":"10.3390\/s19020252"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Viviani, F., Michelini, A., and Mayer, L. (2020, January 21\u201325). RockSpot: An Interferometric Doppler Radar for Rockfall\/Avalanche Detection and Tracking. Proceedings of the 2020 IEEE Radar Conference (RadarConf20), Florence, Italy.","DOI":"10.1109\/RadarConf2043947.2020.9266677"},{"key":"ref_26","unstructured":"Papi, F., Donati, N., and Pieraccini, M. (2014, January 8\u201311). Handy Microwave Sensor for Remote Detection of Structural Vibration. Proceedings of the EWSHM\u20147th European Workshop on Structural Health Monitoring, Nantes, Frances. Available online: https:\/\/inria.hal.science\/hal-01020380."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1109\/TMTT.2011.2178427","article-title":"Millimeter-Wave Technology for Automotive Radar Sensors in the 77 GHz Frequency Band","volume":"60","author":"Hasch","year":"2012","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1109\/TIV.2022.3167733","article-title":"Millimeter Wave FMCW RADARs for Perception, Recognition and Localization in Automotive Applications: A Survey","volume":"7","author":"Venon","year":"2022","journal-title":"IEEE Trans. Intell. Veh."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"012042","DOI":"10.1088\/1742-6596\/2184\/1\/012042","article-title":"Structural Health Monitoring of Large Structures via mmWave Sensing","volume":"2184","author":"Li","year":"2022","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Lian, W., Wang, G., Liu, S., and Zhu, G. (2022, January 9\u201311). Real-Time Deformation Monitoring for Tunnels Using Distributed Millimeter Wave Radar. Proceedings of the 2022 4th International Academic Exchange Conference on Science and Technology Innovation (IAECST), Guangzhou, China.","DOI":"10.1109\/IAECST57965.2022.10061973"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"109582","DOI":"10.1016\/j.ymssp.2022.109582","article-title":"Structural displacement estimation using accelerometer and FMCW millimeter wave radar","volume":"182","author":"Ma","year":"2023","journal-title":"Mech. Syst. Signal Process."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"110408","DOI":"10.1016\/j.ymssp.2023.110408","article-title":"Continuous bridge displacement estimation using millimeter-wave radar, strain gauge and accelerometer","volume":"197","author":"Ma","year":"2023","journal-title":"Mech. Syst. Signal Process."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Pagnini, L., Beni, A., Cioncolini, A., Miccinesi, L., Voci, F., and Pieraccini, M. (2024, January 19\u201324). Application of a W-band Radar for Dynamic Monitoring of Bridges. Proceedings of the 2024 4th URSI Atlantic Radio Science Meeting (AT-RASC), Gran Canaria, Spain.","DOI":"10.46620\/URSIATRASC24\/BCUG8780"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Miccinesi, L., Consumi, T., Beni, A., and Pieraccini, M. (2021). W-band MIMO GB-SAR for Bridge Testing\/Monitoring. Electronics, 10.","DOI":"10.3390\/electronics10182261"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Beni, A., Miccinesi, L., and Pieraccini, M. (2023, January 16\u201321). Correlation between Coherence and Atmospheric Parameters in S, C, AND Ku-Band GBSAR Systems. Proceedings of the IGARSS 2023\u20142023 IEEE International Geoscience and Remote Sensing Symposium, Pasadena, CA, USA.","DOI":"10.1109\/IGARSS52108.2023.10282980"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"452","DOI":"10.1109\/36.739085","article-title":"A fast phase unwrapping algorithm for SAR interferometry","volume":"37","author":"Costantini","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4453","DOI":"10.1109\/TCSI.2022.3193960","article-title":"A Highly Linear Ka-Band GaN-on-Si Active Balanced Mixer for Radar Applications","volume":"69","author":"Cidronali","year":"2022","journal-title":"IEEE Trans. Circuits Syst. I Regul. Pap."},{"key":"ref_38","first-page":"5204412","article-title":"Time Series Phase Unwrapping Based on Graph Theory and Compressed Sensing","volume":"60","author":"Ma","year":"2022","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1109\/MGRS.2021.3065811","article-title":"Artificial Intelligence in Interferometric Synthetic Aperture Radar Phase Unwrapping: A Review","volume":"9","author":"Zhou","year":"2021","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Pu, L., Zhang, X., Zhou, Z., Li, L., Zhou, L., Shi, J., and Wei, S. (2021). A Robust InSAR Phase Unwrapping Method via Phase Gradient Estimation Network. Remote Sens., 13.","DOI":"10.3390\/rs13224564"},{"key":"ref_41","unstructured":"(2024, July 15). IBIS-FM EVO. Available online: https:\/\/idsgeoradar.com\/products\/interferometric-radar\/ibis-fm-evo."},{"key":"ref_42","unstructured":"(2024, July 15). RockSpot. Available online: https:\/\/idsgeoradar.com\/products\/interferometric-radar\/rockspot."},{"key":"ref_43","unstructured":"(2023, August 03). AWR1843BOOST Evaluation Board|TI.com. Available online: https:\/\/www.ti.com\/tool\/AWR1843BOOST."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"2436","DOI":"10.1109\/TGRS.2013.2261077","article-title":"Atmospheric Phase Screen Compensation in Ground-Based SAR With a Multiple-Regression Model Over Mountainous Regions","volume":"52","author":"Iglesias","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1109\/TGE.1975.294402","article-title":"Fading Characteristics of Panchromatic Radar Backscatter from Selected Agricultural Targets","volume":"13","author":"Bush","year":"1975","journal-title":"IEEE Trans. Geosci. Electron."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/17\/3323\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:51:23Z","timestamp":1760111483000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/17\/3323"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,7]]},"references-count":45,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["rs16173323"],"URL":"https:\/\/doi.org\/10.3390\/rs16173323","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,7]]}}}