Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones
The strong winds in tropical cyclones (TCs) are commonly retrieved from cross-polarized SAR images using a geophysical model function (GMF). However, the accuracy of wind retrieval in cross-polarization is significantly reduced at the edges of sub-swaths. In this study, a novel approach to TC wind r...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2023-08-01
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| Series: | Canadian Journal of Remote Sensing |
| Online Access: | http://dx.doi.org/10.1080/07038992.2023.2254839 |
| _version_ | 1797366126463680512 |
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| author | Xianbin Zhao Weizeng Shao Mengyu Hao Xingwei Jiang |
| author_facet | Xianbin Zhao Weizeng Shao Mengyu Hao Xingwei Jiang |
| author_sort | Xianbin Zhao |
| collection | DOAJ |
| description | The strong winds in tropical cyclones (TCs) are commonly retrieved from cross-polarized SAR images using a geophysical model function (GMF). However, the accuracy of wind retrieval in cross-polarization is significantly reduced at the edges of sub-swaths. In this study, a novel approach to TC wind retrieval from VV polarized SAR images is proposed based on using the azimuthal cutoff wavelength to represent the effect of velocity bunching. A total of 12 dual-polarized (VV and VH) Sentinel-1 (S-1) images acquired in the interferometric wide (IW) mode were used, five of which were collocated with measurements taken by the Stepped-Frequency Microwave Radiometer (SFMR) on board an NOAA aircraft. The SAR-based azimuthal cutoff wavelengths were found to be linearly related to the SFMR wind speeds. Based on this finding, an empirical GMF for TC wind speed retrieval from VV S-1 images was constructed. The inversion results from seven images using this approach were validated against the wind products from the Advanced Scatterometer and the European Center for Medium-Range Weather Forecasts. The RMSE of the wind speed was 2.15 m s−1 and the correlation coefficient (COR) was 0.83 at wind speeds of less than 25 m s−1, while the RMSE was 2.66 m s−1 and the COR was 0.97 when compared with wind retrieval using the VH-polarized GMF S1IW.NR at wind speeds greater than 25 m s−1. The proposed algorithm performs well and has two advantages: (1) it is not subject to the saturation problem of the VV backscattering signal and (2) the discontinuity of the retrieval results obtained using VH GMF at the edges of sub-swaths is improved. |
| first_indexed | 2024-03-08T16:59:55Z |
| format | Article |
| id | doaj.art-6c9f4b0ee79049759b29e215a86d4b6f |
| institution | Directory Open Access Journal |
| issn | 1712-7971 |
| language | English |
| last_indexed | 2024-03-08T16:59:55Z |
| publishDate | 2023-08-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Canadian Journal of Remote Sensing |
| spelling | doaj.art-6c9f4b0ee79049759b29e215a86d4b6f2024-01-04T15:59:06ZengTaylor & Francis GroupCanadian Journal of Remote Sensing1712-79712023-08-0149110.1080/07038992.2023.22548392254839Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical CyclonesXianbin Zhao0Weizeng Shao1Mengyu Hao2Xingwei Jiang3College of Meteorology and Oceanography, National University of Defense TechnologyCollege of Marine Sciences, Shanghai Ocean UniversityCollege of Marine Sciences, Shanghai Ocean UniversityNational Satellite Ocean Application Service, Ministry of Natural ResourcesThe strong winds in tropical cyclones (TCs) are commonly retrieved from cross-polarized SAR images using a geophysical model function (GMF). However, the accuracy of wind retrieval in cross-polarization is significantly reduced at the edges of sub-swaths. In this study, a novel approach to TC wind retrieval from VV polarized SAR images is proposed based on using the azimuthal cutoff wavelength to represent the effect of velocity bunching. A total of 12 dual-polarized (VV and VH) Sentinel-1 (S-1) images acquired in the interferometric wide (IW) mode were used, five of which were collocated with measurements taken by the Stepped-Frequency Microwave Radiometer (SFMR) on board an NOAA aircraft. The SAR-based azimuthal cutoff wavelengths were found to be linearly related to the SFMR wind speeds. Based on this finding, an empirical GMF for TC wind speed retrieval from VV S-1 images was constructed. The inversion results from seven images using this approach were validated against the wind products from the Advanced Scatterometer and the European Center for Medium-Range Weather Forecasts. The RMSE of the wind speed was 2.15 m s−1 and the correlation coefficient (COR) was 0.83 at wind speeds of less than 25 m s−1, while the RMSE was 2.66 m s−1 and the COR was 0.97 when compared with wind retrieval using the VH-polarized GMF S1IW.NR at wind speeds greater than 25 m s−1. The proposed algorithm performs well and has two advantages: (1) it is not subject to the saturation problem of the VV backscattering signal and (2) the discontinuity of the retrieval results obtained using VH GMF at the edges of sub-swaths is improved.http://dx.doi.org/10.1080/07038992.2023.2254839 |
| spellingShingle | Xianbin Zhao Weizeng Shao Mengyu Hao Xingwei Jiang Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones Canadian Journal of Remote Sensing |
| title | Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones |
| title_full | Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones |
| title_fullStr | Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones |
| title_full_unstemmed | Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones |
| title_short | Novel Approach to Wind Retrieval from Sentinel-1 SAR in Tropical Cyclones |
| title_sort | novel approach to wind retrieval from sentinel 1 sar in tropical cyclones |
| url | http://dx.doi.org/10.1080/07038992.2023.2254839 |
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