Validation of VIIRS AOD through a Comparison with a Sun Photometer and MODIS AODs over WuhanReportar como inadecuado


Validation of VIIRS AOD through a Comparison with a Sun Photometer and MODIS AODs over Wuhan


Validation of VIIRS AOD through a Comparison with a Sun Photometer and MODIS AODs over Wuhan - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

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State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing LIESMARS, Wuhan University, Wuhan 430079, China

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School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China

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Collaborative Innovation Center for Geospatial Technology, Wuhan 430079, China

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School of Physics and Technology, Wuhan University, 299, Bayi Road, Wuhan 430071, China

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Hubei Collaborative Innovation Center for High-Efficiency Utilization of Solar Energy, Wuhan 430068, China





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Author to whom correspondence should be addressed.



Academic Editors: Yang Liu, Jun Wang, Omar Torres, Richard Müller and Prasad S. Thenkabail

Abstract Visible Infrared Imaging Radiometer Suite VIIRS is a next-generation polar-orbiting operational environmental sensor with a capability for global aerosol observations. A comprehensive validation of VIIRS products is significant for improving product quality, assessing environment quality for human life, and studying regional climate change. In this study, three-year from 1 January 2014 to 31 December 2016 records of VIIRS Intermediate Product IP data and Moderate Resolution Imaging Spectroradiometer MODIS retrievals on aerosol optical depth AOD at 550 nm were evaluated by comparing them to ground sun photometer measurements over Wuhan. Results indicated that VIIRS IP retrievals were underestimated by 5% for the city. A comparison of VIIRS IP retrievals and ground sun photometer measurements showed a lower R2 of 0.55 0.79 for Terra-MODIS and 0.76 for Aqua-MODIS, with only 52% of retrievals falling within the expected error range established by MODIS over land i.e., ±0.05 + 0.15AOD. Bias analyses with different Ångström exponents AE demonstrated that land aerosol model selection of the VIIRS retrieval over Wuhan was appropriate. However, the larger standard deviations i.e., uncertainty of VIIRS AODs than MODIS AODs could be attributed to the less robust retrieval algorithm. Monthly variations displayed largely underestimated AODs of VIIRS in winter, which could be caused by a large positive bias in surface reflectance estimation due to the sparse vegetation and greater surface brightness of Wuhan in this season. The spatial distribution of VIIRS and MODIS AOD observations revealed that the VIIRS IP AODs over high-pollution areas AOD > 0.8 with sparse vegetation were underestimated by more than 20% in Wuhan, and 40% in several regions. Analysis of several clear rural areas AOD < 0.2 with native vegetation indicated an overestimation of about 20% in the northeastern region of the city. These findings showed that the VIIRS IP AOD at 550 nm can provide a solid dataset with a high resolution 750 m for quantitative scientific investigations and environmental monitoring over Wuhan. However, the performance of dark target algorithms in VIIRS was associated with aerosol types and ground vegetation conditions. View Full-Text

Keywords: aerosol; VIIRS; MODIS; sun photometer; AERONET aerosol; VIIRS; MODIS; sun photometer; AERONET





Autor: Wei Wang 1, Feiyue Mao 1,2,3,* , Zengxin Pan 1, Lin Du 1,4 and Wei Gong 1,3,5

Fuente: http://mdpi.com/



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