On the Quality Control of HY-2 Scatterometer High Winds
The operational wind processor for the Ku-band scatterometers onboard HY-2 satellite series uses a quality control (QC) scheme based on the maximum likelihood estimator (MLE). Since it is difficult to discriminate rain contamination from “true” high winds, the MLE-based wind QC is set in a conservat...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/14/21/5565 |
| _version_ | 1827645578616504320 |
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| author | Shuyan Lang Wenming Lin Yi Zhang Yongjun Jia |
| author_facet | Shuyan Lang Wenming Lin Yi Zhang Yongjun Jia |
| author_sort | Shuyan Lang |
| collection | DOAJ |
| description | The operational wind processor for the Ku-band scatterometers onboard HY-2 satellite series uses a quality control (QC) scheme based on the maximum likelihood estimator (MLE). Since it is difficult to discriminate rain contamination from “true” high winds, the MLE-based wind QC is set in a conservative way, which rejects up to ~35% of high winds (<i>w</i> ≥ 20 m/s) in HY-2 scatterometers (HSCATs). In this paper, the sensitivity of MLE and its spatially averaged value (i.e., MLE<sub>m</sub>) to wind quality and rain is reconsidered by analyzing the collocated HSCAT observations and buoy data, as well as rain data from the global precipitation measurement satellite’s microwave imagers. It shows that MLE<sub>m</sub> is more effective than MLE in terms of flagging rain data. More interestingly, the HSCAT high winds are much less strongly affected by rain, compared to the prior Ku-band pencil-beam scatterometers (e.g., RapidScat). Consequently, a MLE<sub>m</sub>-based approach is proposed to improve the HSCAT wind QC, particularly for high winds. The new QC method results in ~8% rejections at 20 m/s and above. Compared to the collocated buoy winds, the HSCAT high winds preserved by the new QC (but rejected by the operational QC) are of fairly good quality. |
| first_indexed | 2024-03-09T18:41:09Z |
| format | Article |
| id | doaj.art-836799eae0a84099a09f4ed479f19506 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-09T18:41:09Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-836799eae0a84099a09f4ed479f195062023-11-24T06:41:03ZengMDPI AGRemote Sensing2072-42922022-11-011421556510.3390/rs14215565On the Quality Control of HY-2 Scatterometer High WindsShuyan Lang0Wenming Lin1Yi Zhang2Yongjun Jia3National Satellite Ocean Application Service, Beijing 100081, ChinaKey Laboratory of Space Ocean Remote Sensing and Application, Ministry of Natural Resources, Beijing 100081, ChinaNational Satellite Ocean Application Service, Beijing 100081, ChinaNational Satellite Ocean Application Service, Beijing 100081, ChinaThe operational wind processor for the Ku-band scatterometers onboard HY-2 satellite series uses a quality control (QC) scheme based on the maximum likelihood estimator (MLE). Since it is difficult to discriminate rain contamination from “true” high winds, the MLE-based wind QC is set in a conservative way, which rejects up to ~35% of high winds (<i>w</i> ≥ 20 m/s) in HY-2 scatterometers (HSCATs). In this paper, the sensitivity of MLE and its spatially averaged value (i.e., MLE<sub>m</sub>) to wind quality and rain is reconsidered by analyzing the collocated HSCAT observations and buoy data, as well as rain data from the global precipitation measurement satellite’s microwave imagers. It shows that MLE<sub>m</sub> is more effective than MLE in terms of flagging rain data. More interestingly, the HSCAT high winds are much less strongly affected by rain, compared to the prior Ku-band pencil-beam scatterometers (e.g., RapidScat). Consequently, a MLE<sub>m</sub>-based approach is proposed to improve the HSCAT wind QC, particularly for high winds. The new QC method results in ~8% rejections at 20 m/s and above. Compared to the collocated buoy winds, the HSCAT high winds preserved by the new QC (but rejected by the operational QC) are of fairly good quality.https://www.mdpi.com/2072-4292/14/21/5565scatterometerhigh windsquality controlmaximum likelihood estimator (MLE)HY-2 satellite |
| spellingShingle | Shuyan Lang Wenming Lin Yi Zhang Yongjun Jia On the Quality Control of HY-2 Scatterometer High Winds Remote Sensing scatterometer high winds quality control maximum likelihood estimator (MLE) HY-2 satellite |
| title | On the Quality Control of HY-2 Scatterometer High Winds |
| title_full | On the Quality Control of HY-2 Scatterometer High Winds |
| title_fullStr | On the Quality Control of HY-2 Scatterometer High Winds |
| title_full_unstemmed | On the Quality Control of HY-2 Scatterometer High Winds |
| title_short | On the Quality Control of HY-2 Scatterometer High Winds |
| title_sort | on the quality control of hy 2 scatterometer high winds |
| topic | scatterometer high winds quality control maximum likelihood estimator (MLE) HY-2 satellite |
| url | https://www.mdpi.com/2072-4292/14/21/5565 |
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