{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:23:31Z","timestamp":1760145811102,"version":"build-2065373602"},"reference-count":28,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2024,9,5]],"date-time":"2024-09-05T00:00:00Z","timestamp":1725494400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea (NRF)","doi-asserted-by":"publisher","award":["RS-2023-00252169"],"award-info":[{"award-number":["RS-2023-00252169"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Understanding the characteristics of underwater sound channels is essential for various remote sensing applications. Typically, the time-domain Green\u2019s function or channel impulse response (CIR) is obtained using computationally intensive acoustic propagation models that rely on accurate environmental data, such as sound speed profiles and bathymetry. Ray-based blind deconvolution (RBD) offers a less computationally demanding alternative using plane-wave beamforming to estimate the Green\u2019s function. However, the presence of noise can obscure low coherence ray arrivals, making accurate estimation challenging. This paper introduces a method using the waveguide invariant to improve the signal-to-noise ratio (SNR) of broadband Green\u2019s functions for a moving source without prior knowledge of range. By utilizing RBD and the frequency shifts from the striation slope, we coherently combine individual Green\u2019s functions at adjacent ranges, significantly improving the SNR. In this study, we demonstrated the proposed method via simulation and broadband noise data (200\u2013900 Hz) collected from a moving ship in 100 m deep shallow water.<\/jats:p>","DOI":"10.3390\/s24175782","type":"journal-article","created":{"date-parts":[[2024,9,5]],"date-time":"2024-09-05T10:03:32Z","timestamp":1725530612000},"page":"5782","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Improvement of a Green\u2019s Function Estimation for a Moving Source Using the Waveguide Invariant Theory"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7651-3115","authenticated-orcid":false,"given":"Daehwan","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Ocean Engineering, Korea Maritime and Ocean University, Busan 49112, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1839-1666","authenticated-orcid":false,"given":"Donghyeon","family":"Kim","sequence":"additional","affiliation":[{"name":"Scripps Institution of Oceanography, La Jolla, CA 92093-0238, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gihoon","family":"Byun","sequence":"additional","affiliation":[{"name":"Department of Convergence Study on the Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8514-3187","authenticated-orcid":false,"given":"Jeasoo","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Ocean Engineering, Korea Maritime and Ocean University, Busan 49112, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5835-8775","authenticated-orcid":false,"given":"Heechun","family":"Song","sequence":"additional","affiliation":[{"name":"Scripps Institution of Oceanography, La Jolla, CA 92093-0238, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1109\/48.820733","article-title":"The state of the art in underwater acoustic telemetry","volume":"25","author":"Kilfoyle","year":"2000","journal-title":"IEEE J. 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