A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model
Current PM<sub>2.5</sub> retrieval maps have many missing values, which seriously hinders their performance in real applications. This paper presents a framework to map full-coverage daily average PM<sub>2.5</sub> concentrations from MODIS C6 aerosol optical depth (AOD) produ...
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| Format: | Article |
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MDPI AG
2019-07-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/11/13/1558 |
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| author | Zhenqun Hua Weiwei Sun Gang Yang Qian Du |
| author_facet | Zhenqun Hua Weiwei Sun Gang Yang Qian Du |
| author_sort | Zhenqun Hua |
| collection | DOAJ |
| description | Current PM<sub>2.5</sub> retrieval maps have many missing values, which seriously hinders their performance in real applications. This paper presents a framework to map full-coverage daily average PM<sub>2.5</sub> concentrations from MODIS C6 aerosol optical depth (AOD) products and fill missing pixels in both the AOD and PM<sub>2.5</sub> maps. First, a two-stage inversed variance weights (IVW) algorithm was adopted to fuse the MODIS C6 Terra and Aqua AOD products, which fills missing data in MODIS standard AOD data and obtains a high coverage daily average. After that, using the fused MODIS daily average AOD and ground-level PM<sub>2.5</sub> in all grid cells, a two-stage generalized additive model (GAM) was implemented to obtain the full-coverage PM<sub>2.5</sub> concentrations. Experiments on the Yangtze River Delta (YRD) in 2013−2016 were carefully designed to validate the performance of our proposed framework. The results show that the two-stage IVW could not only improve the spatial coverage of MODIS AOD against the original standard product by 230%, but could also keep its data accuracy. When compared with the ground-level measurements, the two-stage GAM can obtain accurate PM<sub>2.5</sub> concentration estimates (R<sup>2</sup> = 0.78, RMSE = 19.177 μg/m<sup>3</sup>, and RPE = 28.9%). Moreover, our method performs better than the inverse distance weighted method and kriging methods in mapping full-coverage daily PM<sub>2.5</sub> concentrations. Therefore, the proposed framework provides a good methodology for retrieving full-coverage daily average PM<sub>2.5</sub> concentrations from MODIS standard AOD products. |
| first_indexed | 2024-04-11T18:42:22Z |
| format | Article |
| id | doaj.art-e244dee45c834583b57f4fc6f8be65c1 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-04-11T18:42:22Z |
| publishDate | 2019-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-e244dee45c834583b57f4fc6f8be65c12022-12-22T04:08:56ZengMDPI AGRemote Sensing2072-42922019-07-011113155810.3390/rs11131558rs11131558A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM ModelZhenqun Hua0Weiwei Sun1Gang Yang2Qian Du3Department of Geography and Spatial Information Techniques, Ningbo University, Ningbo, Zhejiang 315211, ChinaDepartment of Geography and Spatial Information Techniques, Ningbo University, Ningbo, Zhejiang 315211, ChinaDepartment of Geography and Spatial Information Techniques, Ningbo University, Ningbo, Zhejiang 315211, ChinaDepartment of Electrical and Computer Engineering, Mississippi State University, Starkville, MS 39762, USACurrent PM<sub>2.5</sub> retrieval maps have many missing values, which seriously hinders their performance in real applications. This paper presents a framework to map full-coverage daily average PM<sub>2.5</sub> concentrations from MODIS C6 aerosol optical depth (AOD) products and fill missing pixels in both the AOD and PM<sub>2.5</sub> maps. First, a two-stage inversed variance weights (IVW) algorithm was adopted to fuse the MODIS C6 Terra and Aqua AOD products, which fills missing data in MODIS standard AOD data and obtains a high coverage daily average. After that, using the fused MODIS daily average AOD and ground-level PM<sub>2.5</sub> in all grid cells, a two-stage generalized additive model (GAM) was implemented to obtain the full-coverage PM<sub>2.5</sub> concentrations. Experiments on the Yangtze River Delta (YRD) in 2013−2016 were carefully designed to validate the performance of our proposed framework. The results show that the two-stage IVW could not only improve the spatial coverage of MODIS AOD against the original standard product by 230%, but could also keep its data accuracy. When compared with the ground-level measurements, the two-stage GAM can obtain accurate PM<sub>2.5</sub> concentration estimates (R<sup>2</sup> = 0.78, RMSE = 19.177 μg/m<sup>3</sup>, and RPE = 28.9%). Moreover, our method performs better than the inverse distance weighted method and kriging methods in mapping full-coverage daily PM<sub>2.5</sub> concentrations. Therefore, the proposed framework provides a good methodology for retrieving full-coverage daily average PM<sub>2.5</sub> concentrations from MODIS standard AOD products.https://www.mdpi.com/2072-4292/11/13/1558full-coverage daily average PM<sub>2.5</sub>MODIS C6 AODtwo-stage inverse variance weightstwo-stage generalized additive model |
| spellingShingle | Zhenqun Hua Weiwei Sun Gang Yang Qian Du A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model Remote Sensing full-coverage daily average PM<sub>2.5</sub> MODIS C6 AOD two-stage inverse variance weights two-stage generalized additive model |
| title | A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model |
| title_full | A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model |
| title_fullStr | A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model |
| title_full_unstemmed | A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model |
| title_short | A Full-Coverage Daily Average PM<sub>2.5</sub> Retrieval Method with Two-Stage IVW Fused MODIS C6 AOD and Two-Stage GAM Model |
| title_sort | full coverage daily average pm sub 2 5 sub retrieval method with two stage ivw fused modis c6 aod and two stage gam model |
| topic | full-coverage daily average PM<sub>2.5</sub> MODIS C6 AOD two-stage inverse variance weights two-stage generalized additive model |
| url | https://www.mdpi.com/2072-4292/11/13/1558 |
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