A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface
Sea surface emissivity (SSE) is a key variable in the estimation of sea surface temperature and the sea surface radiation budget. A physical base SSE model with adequate accuracy and acceptable computational efficiency is highly desired. This paper develops a Monte Carlo ray-tracing model to compute...
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| Format: | Article |
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MDPI AG
2019-05-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/19/9/2166 |
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| author | Jie Cheng Xiaolong Cheng Xiangchen Meng Guanhua Zhou |
| author_facet | Jie Cheng Xiaolong Cheng Xiangchen Meng Guanhua Zhou |
| author_sort | Jie Cheng |
| collection | DOAJ |
| description | Sea surface emissivity (SSE) is a key variable in the estimation of sea surface temperature and the sea surface radiation budget. A physical base SSE model with adequate accuracy and acceptable computational efficiency is highly desired. This paper develops a Monte Carlo ray-tracing model to compute the SSE of a wind-roughened sea surface. The adoption of a two-dimensional continuous surface model and averaging the two polarization components in advance before ray-tracing gives the model acceptable computational efficiency. The developed model can output the contributions of direct emission and the reflected component to the effective emissivity. The contribution of the reflected component to the effective emissivity reaches 0.035 at an 80° emission angle for a wind speed larger than 10 m/s. The emissivity spectra and channel emissivities collected from two field campaigns and one set of outdoor measurements are used to validate the developed model. Statistical results indicate that the absolute value of bias or difference is less than 0.5% when the view angle is less than 65°, which means the retrieval accuracy of sea surface temperature (SST) is guaranteed from the view of SSE. When the view angle increases, the accuracy of the developed model degraded, especially at the view angle of 85°. Without considering this view angle, the absolute value of bias or difference is less than 0.016, and the root mean square difference (RMSD) is less than 0.018. |
| first_indexed | 2024-04-11T18:41:01Z |
| format | Article |
| id | doaj.art-adb91925588d43a381ae3c6c025ca20b |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T18:41:01Z |
| publishDate | 2019-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-adb91925588d43a381ae3c6c025ca20b2022-12-22T04:08:59ZengMDPI AGSensors1424-82202019-05-01199216610.3390/s19092166s19092166A Monte Carlo Emissivity Model for Wind-Roughened Sea SurfaceJie Cheng0Xiaolong Cheng1Xiangchen Meng2Guanhua Zhou3State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, ChinaState Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, ChinaState Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences, Beijing 100875, ChinaSchool of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191, ChinaSea surface emissivity (SSE) is a key variable in the estimation of sea surface temperature and the sea surface radiation budget. A physical base SSE model with adequate accuracy and acceptable computational efficiency is highly desired. This paper develops a Monte Carlo ray-tracing model to compute the SSE of a wind-roughened sea surface. The adoption of a two-dimensional continuous surface model and averaging the two polarization components in advance before ray-tracing gives the model acceptable computational efficiency. The developed model can output the contributions of direct emission and the reflected component to the effective emissivity. The contribution of the reflected component to the effective emissivity reaches 0.035 at an 80° emission angle for a wind speed larger than 10 m/s. The emissivity spectra and channel emissivities collected from two field campaigns and one set of outdoor measurements are used to validate the developed model. Statistical results indicate that the absolute value of bias or difference is less than 0.5% when the view angle is less than 65°, which means the retrieval accuracy of sea surface temperature (SST) is guaranteed from the view of SSE. When the view angle increases, the accuracy of the developed model degraded, especially at the view angle of 85°. Without considering this view angle, the absolute value of bias or difference is less than 0.016, and the root mean square difference (RMSD) is less than 0.018.https://www.mdpi.com/1424-8220/19/9/2166sea surface emissivityMonte Carlo modelray-tracingbroadband emissivitythermal-infraredSST |
| spellingShingle | Jie Cheng Xiaolong Cheng Xiangchen Meng Guanhua Zhou A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface Sensors sea surface emissivity Monte Carlo model ray-tracing broadband emissivity thermal-infrared SST |
| title | A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface |
| title_full | A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface |
| title_fullStr | A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface |
| title_full_unstemmed | A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface |
| title_short | A Monte Carlo Emissivity Model for Wind-Roughened Sea Surface |
| title_sort | monte carlo emissivity model for wind roughened sea surface |
| topic | sea surface emissivity Monte Carlo model ray-tracing broadband emissivity thermal-infrared SST |
| url | https://www.mdpi.com/1424-8220/19/9/2166 |
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