{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T02:02:52Z","timestamp":1785376972691,"version":"3.55.0"},"reference-count":35,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2020,11,20]],"date-time":"2020-11-20T00:00:00Z","timestamp":1605830400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of Education, University and Research","award":["AIM 1807508-1"],"award-info":[{"award-number":["AIM 1807508-1"]}]},{"name":"Arbi Dario S.p.A.","award":["none"],"award-info":[{"award-number":["none"]}]},{"DOI":"10.13039\/100006363","name":"National Geographic Society","doi-asserted-by":"publisher","award":["NGS-56544"],"award-info":[{"award-number":["NGS-56544"]}],"id":[{"id":"10.13039\/100006363","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Underwater robots emit sound during operations which can deteriorate the quality of acoustic data recorded by on-board sensors or disturb marine fauna during in vivo observations. Notwithstanding this, there have only been a few attempts at characterizing the acoustic emissions of underwater robots in the literature, and the datasheets of commercially available devices do not report information on this topic. This work has a twofold goal. First, we identified a setup consisting of a camera directly mounted on the robot structure to acquire the acoustic data and two indicators (i.e., spectral roll-off point and noise introduced to the environment) to provide a simple and intuitive characterization of the acoustic emissions of underwater robots carrying out specific maneuvers in specific environments. Second, we performed the proposed analysis on three underwater robots belonging to the classes of remotely operated vehicles and underwater legged robots. Our results showed how the legged device produced a clearly different signature compared to remotely operated vehicles which can be an advantage in operations that require low acoustic disturbance. Finally, we argue that the proposed indicators, obtained through a standardized procedure, may be a useful addition to datasheets of existing underwater robots.<\/jats:p>","DOI":"10.3390\/s20226644","type":"journal-article","created":{"date-parts":[[2020,11,20]],"date-time":"2020-11-20T02:09:07Z","timestamp":1605838147000},"page":"6644","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["A Minimal Metric for the Characterization of Acoustic Noise Emitted by Underwater Vehicles"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9066-692X","authenticated-orcid":false,"given":"Giacomo","family":"Picardi","sequence":"first","affiliation":[{"name":"The BioRobotics Institute, Scuola Superiore Sant\u2019Anna, 56127 Pisa, Italy"},{"name":"Department of Excellence in Robotics &amp; AI, Scuola Superiore Sant\u2019Anna, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Clara","family":"Borrelli","sequence":"additional","affiliation":[{"name":"Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5803-1702","authenticated-orcid":false,"given":"Augusto","family":"Sarti","sequence":"additional","affiliation":[{"name":"Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2581-3430","authenticated-orcid":false,"given":"Giovanni","family":"Chimienti","sequence":"additional","affiliation":[{"name":"Department of Biology and CoNISMa LRU, University of Bari Aldo Moro, 70125 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcello","family":"Calisti","sequence":"additional","affiliation":[{"name":"The BioRobotics Institute, Scuola Superiore Sant\u2019Anna, 56127 Pisa, Italy"},{"name":"Department of Excellence in Robotics &amp; AI, Scuola Superiore Sant\u2019Anna, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/S0921-8009(99)00079-8","article-title":"The ecological, economic, and social importance of the oceans","volume":"31","author":"Costanza","year":"1999","journal-title":"Ecol. 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