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Atmospheric Channel
Published in Hamid Hemmati, Near-Earth Laser Communications, 2018
Concerning atmospheric transmittance and sky radiance, these parameters can be obtained in principle by software simulation or by measurement in situ. However, after a number of measurement campaigns developed in recent years, one can also use the large number of data that already exists for the determination of atmospheric transmittance and sky radiance. For instance, the NASA AERONET program has deployed a number of sun-photometers around the world for the characterization of aerosol concentrations with measurements of the atmospheric transmittance and radiance. The AERONET Program [35], makes readily available a multi-year data bank of atmospheric transmission and radiance for a number of wavelength channels collected by sensors distributed on locations all over the world.
2.5 Concentrations in a Metropolitan Region
Published in Ni-Bin Chang, Kaixu Bai, Multisensor Data Fusion and Machine Learning for Environmental Remote Sensing, 2018
This chapter emphasizes the data merging of satellite AOD products collected by the MODIS-Terra and MODIS-Aqua by making use of the Modified Quantile-Quantile Adjustment (MQQA) algorithm (Bai et al., 2016b). In addition, AERONET (AErosol RObotic NETwork) program is a federation of ground-based remote sensing aerosol networks established by the National Aeronautics and Space Administration (NASA) and PHOtométrie pour le Traitement Opérationnel de Normalisation Satellitaire; Univ. of Lille 1, CNES, and CNRS-INSU (PHOTONS) (Figure 19.1). It provides continuous cloud-screened observations of spectral AOD, precipitable water, and inversion aerosol products in diverse aerosol regimes, and can be used as the ground truth to verify the merged remote sensing AOD products. For further verification, ground-based AOD measurements recorded by instruments from AERONET were used in our case study. Overall, this study aims to: (1) compare the accuracy of data merging of two satellite AOD products against the AERONET AOD measurements, and (2) examine the feasibility of predicting PM2.5 concentrations using linear or nonlinear retrieval algorithms in a metropolitan region against the ground-based measurements collected from a few local monitoring stations managed by the United States Environmental Protection Agency (US-EPA).
Atmospheric Channel
Published in Hamid Hemmati, Near-Earth Laser Communications, 2020
Concerning atmospheric transmittance and sky radiance, these parameters can be obtained in principle by software simulation or by measurement in situ. However, after a number of measurement campaigns developed in recent years, one can also use the large number of data that already exists for the determination of atmospheric transmittance and sky radiance. For instance, the NASA AERONET program has deployed a number of sun photometers around the world for the characterization of aerosol concentrations with measurements of the atmospheric transmittance and radiance. The AERONET Program [39] makes readily available a multiyear data bank of atmospheric transmission and radiance for a number of wavelength channels collected by sensors distributed on locations all over the world.
Influence of observation angle change on satellite retrieval of aerosol optical depth
Published in Tellus B: Chemical and Physical Meteorology, 2021
Lijuan Chen, Ren Wang, Jiamei Han, Yong Zha
AERONET is a global network of ground-based sun photometers. The CIMEL318 instrument is utilized to observe aerosol optical characteristics. AERONET provides near-truth data for satellite and model verification at the site locations. The center wavelengths of the CIMEL318 instrument are 340 nm, 380 nm, 440 nm, 500 nm, 670 nm, 870 nm, 936 nm, 1020 nm, and 1640 nm. The measured values of the 936 nm channel are used to obtain the total water vapor content in the atmosphere. The measured values of the other channels are used to retrieve AOD. The retrieval error is about 0.01–0.02 (Eck et al., 1999). AERONET aerosol product quality levels are divided into three categories: Level 1.0 is the raw data without cloud screening, and level 1.5 is the cloud detection processing data, and level 2.0 data removes cloud pollution and has quality assurance data. The number of samples of data available at AERONET 2.0 level is very limited, and thus to ensure enough verification data, we uses AERONET 1.5 level data (AERONET version 3) from 2016 to 2018 to verify the results of remote sensing retrieval. We used two stations in the Yangtze River Delta region that continue to provide observation data, i.e. Taihu (31.421oN, 120.215oE) and Xuzhou-CUMT (34.217oN, 117.142oE) stations (Fig. 1), which were used to verify the retrieved MISR AOD.
Satellite remote sensing of aerosol optical depth: advances, challenges, and perspectives
Published in Critical Reviews in Environmental Science and Technology, 2020
Xiaoli Wei, Ni-Bin Chang, Kaixu Bai, Wei Gao
AERONET is a ground-based monitoring network equipped with sun photometers and a solar-powered CIMEL Electronique 318 A radiometer to provide a long-term, continuous, and readily accessible public domain database of aerosol optical, microphysical, and radiative properties (Smirnov, 2004). The network was initially established by NASA (National Space Administration Agency) and PHOTONS (PHOtométrie pour le Traitement Opérationnel de Normalization Satellitaire; Univ. of Lille 1, CNES, and CNRS-INSU) to monitor long time series aerosol characterization, validate satellite retrievals, and synergize with other databases around the world. This network provides 3 types of AOD products: Version 1.0 (unscreened), Level 1.5 (cloud-screened and quality controlled), and Level 2.0 (quality-assured). In addition to AOD products, this database provides a suite of diversity products such as aerosol type, mixtures, transport region, and source. The distribution of site stations is shown in Figure 1.
Retrieval and validation of long-term aerosol optical depth from AVHRR data over China
Published in International Journal of Digital Earth, 2022
Chunlin Jin, Yong Xue, Xingxing Jiang, Shuhui Wu, Yuxin Sun
AERONET is a global ground-based atmospheric aerosol observation network. Its long-term observation data have been widely used in aerosol research and characterization, satellite data validation, etc. CARSNET is also the network created by China which has been proven to have the same accuracy as AERONET (Xie et al. 2011) and has more stations in China. They can provide accurate AOD at 1020, 870, 670, 440 nm, and Angstrom exponent which can calculate AOD at other wavelengths. Ground-based stations used in the paper are illustrated in Figure 1. Due to the dearth of long-term observation sites in China, some AERONET sites around China are also chosen for the verification of the results.