{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:05:25Z","timestamp":1760148325195,"version":"build-2065373602"},"reference-count":48,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,4,20]],"date-time":"2023-04-20T00:00:00Z","timestamp":1681948800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61931025","U2006207","21CX06015A","2022003"],"award-info":[{"award-number":["61931025","U2006207","21CX06015A","2022003"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Key Program of Joint Fund of the National Natural Science Foundation of China and Shandong Province","award":["61931025","U2006207","21CX06015A","2022003"],"award-info":[{"award-number":["61931025","U2006207","21CX06015A","2022003"]}]},{"name":"Fundamental Research Funds for the Central Universities","award":["61931025","U2006207","21CX06015A","2022003"],"award-info":[{"award-number":["61931025","U2006207","21CX06015A","2022003"]}]},{"name":"Fund of Technology Innovation Center for Ocean Telemetry, Ministry of Natural Resources","award":["61931025","U2006207","21CX06015A","2022003"],"award-info":[{"award-number":["61931025","U2006207","21CX06015A","2022003"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Knowledge of the ocean backscatter at various azimuth angles is critical to the radar detection of the ocean environment. In this study, the modified two-scale model (TSM), which introduces a correction term in the conventional TSM, is improved based on the empirical model, CMOD5.n. Then, the influences of different directional wave spectra on the prediction of azimuthal behavior of ocean radar backscatter are investigated by comparing the simulated results with CMOD5.n and the Advanced Scatterometer (ASCAT) measurements. The results show that the overall performance of the single spectra of D, A, E, and H18 and the composite spectra of AH18 and AEH18 in predicting ocean backscatter are different at different wind speeds and incidence angles. Generally, the AH18 spectrum has better performance at low and moderate wind speeds, while the A spectrum works better at high wind speed. Nevertheless, the wave spectra have little effect on the prediction of the azimuthal fluctuation of scattering, which is highly dependent on the directional spreading function. The relative patterns of azimuthal undulation produced by different spreading functions are rather different at different wind speeds, but similar under different incidence angles. The Gaussian spreading function generally has better performance in predicting the azimuthal fluctuation of scattering.<\/jats:p>","DOI":"10.3390\/rs15082191","type":"journal-article","created":{"date-parts":[[2023,4,21]],"date-time":"2023-04-21T01:33:43Z","timestamp":1682040823000},"page":"2191","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of Directional Wave Spectra on the Modeling of Ocean Radar Backscatter at Various Azimuth Angles by a Modified Two-Scale Method"],"prefix":"10.3390","volume":"15","author":[{"given":"Qiushuang","family":"Yan","sequence":"first","affiliation":[{"name":"College of Oceanography and Space Informatics, China University of Petroleum, Qingdao 266580, China"}]},{"given":"Yuqi","family":"Wu","sequence":"additional","affiliation":[{"name":"College of Oceanography and Space Informatics, China University of Petroleum, Qingdao 266580, China"}]},{"given":"Chenqing","family":"Fan","sequence":"additional","affiliation":[{"name":"Technology Innovation Center for Ocean Telemetry, Ministry of Natural Resources, Qingdao 266061, China"},{"name":"First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3358-8245","authenticated-orcid":false,"given":"Junmin","family":"Meng","sequence":"additional","affiliation":[{"name":"Technology Innovation Center for Ocean Telemetry, Ministry of Natural Resources, Qingdao 266061, China"},{"name":"First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China"}]},{"given":"Tianran","family":"Song","sequence":"additional","affiliation":[{"name":"College of Oceanography and Space Informatics, China University of Petroleum, Qingdao 266580, China"}]},{"given":"Jie","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Oceanography and Space Informatics, China University of Petroleum, Qingdao 266580, China"},{"name":"Technology Innovation Center for Ocean Telemetry, Ministry of Natural Resources, Qingdao 266061, China"},{"name":"First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1002\/cpa.3160040206","article-title":"Reflection of electromagnetic waves from slightly rough surfaces","volume":"4","author":"Rice","year":"1951","journal-title":"Commun. 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