{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T19:14:35Z","timestamp":1767899675089,"version":"3.49.0"},"reference-count":33,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2023,9,28]],"date-time":"2023-09-28T00:00:00Z","timestamp":1695859200000},"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>The macroalgal bloom (MAB) is caused by brown algae forming a floating mat. Most of its parts stay below the water surface, unlike green algae; thus, its backscatter value becomes weaker in the synthetic aperture radar (SAR) images, such as Sentinel\u22121, due to the dampening effect. Thus, brown algae patches appear to be thin strands in contrast to green algae and their detection by using a global threshold, which is challenging due to a similarity between the MAB patch and the ship\u2019s sidelobe in the case of pixel value. Therefore, a novel approach is proposed to detect the MAB from the Sentinel\u22121 image by eliminating the ship\u2019s sidelobe. An individually optimized threshold is applied to extract the MAB and the ships with sidelobes from the image. Then, parameters are adjusted based on the object\u2019s area information and the ratio of length and width to filter out ships with sidelobes and clutter objects. With this method, an average detection accuracy of 82.2% is achieved by comparing it with the reference data. The proposed approach is simple and effective for detecting the thin MAB patch from the SAR image.<\/jats:p>","DOI":"10.3390\/rs15194764","type":"journal-article","created":{"date-parts":[[2023,9,29]],"date-time":"2023-09-29T05:48:13Z","timestamp":1695966493000},"page":"4764","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Detection of Macroalgal Bloom from Sentinel\u22121 Imagery"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7079-3080","authenticated-orcid":false,"given":"Sree Juwel Kumar","family":"Chowdhury","sequence":"first","affiliation":[{"name":"Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Republic of Korea"},{"name":"Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime & Ocean University, Busan 49112, Republic of Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4632-4062","authenticated-orcid":false,"given":"Ahmed","family":"Harun-Al-Rashid","sequence":"additional","affiliation":[{"name":"Department of Aquatic Resource Management, Sylhet Agricultural University, Sylhet 3100, Bangladesh"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6882-7325","authenticated-orcid":false,"given":"Chan-Su","family":"Yang","sequence":"additional","affiliation":[{"name":"Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Republic of Korea"},{"name":"Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime & Ocean University, Busan 49112, Republic of Korea"},{"name":"Marine Technology and Convergence Engineering, University of Science & Technology, Daejeon 34113, Republic of Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6603-2337","authenticated-orcid":false,"given":"Dae-Woon","family":"Shin","sequence":"additional","affiliation":[{"name":"Maritime Security and Safety Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Republic of Korea"},{"name":"Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime & Ocean University, Busan 49112, Republic of Korea"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1007\/s10201-009-0278-4","article-title":"Green tide formed by free-floating Ulva spp. at Yatsu tidal flat, Japan","volume":"10","author":"Yabe","year":"2009","journal-title":"Limnology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1126\/science.aaw7912","article-title":"The great Atlantic Sargassum belt","volume":"365","author":"Wang","year":"2019","journal-title":"Science"},{"key":"ref_3","first-page":"1","article-title":"Development and implementation of Sargassum early advisory system (SEAS)","volume":"81","author":"Webster","year":"2013","journal-title":"Shore Beach"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"888","DOI":"10.1016\/j.marpolbul.2009.01.013","article-title":"World\u2019s largest macroalgal bloom caused by expansion of seaweed aquaculture in China","volume":"58","author":"Liu","year":"2009","journal-title":"Mar. 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