A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST
Land-surface temperature (LST) plays a key role in the physical processes of surface energy and water balance from local through global scales. The widely used one kilometre resolution daily Moderate Resolution Imaging Spectroradiometer (MODIS) LST product has missing values due to the influence of...
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| Format: | Article |
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MDPI AG
2020-05-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/12/10/1641 |
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| author | Yunfei Zhang Yunhao Chen Jing Li Xi Chen |
| author_facet | Yunfei Zhang Yunhao Chen Jing Li Xi Chen |
| author_sort | Yunfei Zhang |
| collection | DOAJ |
| description | Land-surface temperature (LST) plays a key role in the physical processes of surface energy and water balance from local through global scales. The widely used one kilometre resolution daily Moderate Resolution Imaging Spectroradiometer (MODIS) LST product has missing values due to the influence of clouds. Therefore, a large number of clear-sky LST reconstruction methods have been developed to obtain spatially continuous LST datasets. However, the clear-sky LST is a theoretical value that is often an overestimate of the real value. In fact, the real LST (also known as cloudy-sky LST) is more necessary and more widely used. The existing cloudy-sky LST algorithms are usually somewhat complicated, and the accuracy needs to be improved. It is necessary to convert the clear-sky LST obtained by the currently better-developed methods into cloudy-sky LST. We took the clear-sky LST, cloud-cover duration, downward shortwave radiation, albedo and normalized difference vegetation index (NDVI) as five independent variables and the real LST at the ground stations as the dependent variable to perform multiple linear regression. The mean absolute error (MAE) of the cloudy-sky LST retrieved by this method ranged from 3.5–3.9 K. We further analyzed different cases of the method, and the results suggested that this method has good flexibility. When we chose fewer independent variables, different clear-sky algorithms, or different regression tools, we also achieved good results. In addition, the method calculation process was relatively simple and can be applied to other research areas. This study preliminarily explored the influencing factors of the real LST and can provide a possible option for researchers who want to obtain cloudy-sky LST through clear-sky LST, that is, a convenient conversion method. This article lays the foundation for subsequent research in various fields that require real LST. |
| first_indexed | 2024-03-10T19:41:41Z |
| format | Article |
| id | doaj.art-54f55875d4514b92b77817cd04ebf792 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T19:41:41Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-54f55875d4514b92b77817cd04ebf7922023-11-20T01:08:21ZengMDPI AGRemote Sensing2072-42922020-05-011210164110.3390/rs12101641A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LSTYunfei Zhang0Yunhao Chen1Jing Li2Xi Chen3State Key Laboratory of Remote Sensing Science, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, ChinaState Key Laboratory of Remote Sensing Science, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, ChinaState Key Laboratory of Remote Sensing Science, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, ChinaInstitute of RS and GIS, School of Earth and Space Sciences, Peking University, Beijing 100871, ChinaLand-surface temperature (LST) plays a key role in the physical processes of surface energy and water balance from local through global scales. The widely used one kilometre resolution daily Moderate Resolution Imaging Spectroradiometer (MODIS) LST product has missing values due to the influence of clouds. Therefore, a large number of clear-sky LST reconstruction methods have been developed to obtain spatially continuous LST datasets. However, the clear-sky LST is a theoretical value that is often an overestimate of the real value. In fact, the real LST (also known as cloudy-sky LST) is more necessary and more widely used. The existing cloudy-sky LST algorithms are usually somewhat complicated, and the accuracy needs to be improved. It is necessary to convert the clear-sky LST obtained by the currently better-developed methods into cloudy-sky LST. We took the clear-sky LST, cloud-cover duration, downward shortwave radiation, albedo and normalized difference vegetation index (NDVI) as five independent variables and the real LST at the ground stations as the dependent variable to perform multiple linear regression. The mean absolute error (MAE) of the cloudy-sky LST retrieved by this method ranged from 3.5–3.9 K. We further analyzed different cases of the method, and the results suggested that this method has good flexibility. When we chose fewer independent variables, different clear-sky algorithms, or different regression tools, we also achieved good results. In addition, the method calculation process was relatively simple and can be applied to other research areas. This study preliminarily explored the influencing factors of the real LST and can provide a possible option for researchers who want to obtain cloudy-sky LST through clear-sky LST, that is, a convenient conversion method. This article lays the foundation for subsequent research in various fields that require real LST.https://www.mdpi.com/2072-4292/12/10/1641land-surface temperatureMODIS LSTcloudy-sky LST |
| spellingShingle | Yunfei Zhang Yunhao Chen Jing Li Xi Chen A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST Remote Sensing land-surface temperature MODIS LST cloudy-sky LST |
| title | A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST |
| title_full | A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST |
| title_fullStr | A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST |
| title_full_unstemmed | A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST |
| title_short | A Simple Method for Converting 1-km Resolution Daily Clear-Sky LST into Real LST |
| title_sort | simple method for converting 1 km resolution daily clear sky lst into real lst |
| topic | land-surface temperature MODIS LST cloudy-sky LST |
| url | https://www.mdpi.com/2072-4292/12/10/1641 |
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