Design and Application of Global Calibration-Site Network Database

Wenbin, 徐文斌 Xu; Jianmin, 史剑民 Shi; Xiaobing, 郑小兵 Zheng; Weining, 易维宁 Yi

doi:10.3788/aos201434.1101002

Cited by 1 publication

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“…A change in the AOD led to opposite trends for direct and diffuse transmittances, revealing an inverse relationship, and, as the same difference was considered in AOD retrieval, the relative difference was symmetrical (Figure 17). For the reflectance-based method (Equation ( 4)), both the direct transmittance and the diffuse transmittance (T dir (θ s ), T di f (θ s ), T dir (θ v ), and T di f (θ v )) were affected by AOD errors according to Equations (5) and (6). The direct transmittance increased or decreased with a change in the AOD, while the diffuse transmittance changed in the opposite direction, revealing a "when one falls, another rises" relation.…”

Section: Uncertainty Analysis Of Aod Retrievalmentioning

confidence: 99%

“…The reflectance-, irradiance-, and radiance-based methods, which were first proposed and applied in radiometric calibration tests conducted by the Remote Sensing Group of the University of Arizona, are three representative in-situ vicarious radiometric calibration methods [4]. According to data published by the United States, France, and other countries, the accuracy of absolute radiometric calibration using the current vicarious radiometric calibration methods in the visible and near-infrared bands is 3-5% [5]. The reflectance-based method depends on ground-based measurements, including ground reflectance measurements and atmospheric parameters.…”

Section: Introductionmentioning

confidence: 99%

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Vicarious Radiometric Calibration of the Multispectral Imager Onboard SDGSAT-1 over the Dunhuang Calibration Site, China

Cui

Zhang

et al. 2023

Remote Sensing

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The multispectral imager (MII), onboard the Sustainable Development Science Satellite 1 (SDGSAT-1), performs detailed terrestrial change detection and coastal monitoring. SDGSAT-1 was launched at 2:19 UTC on 5 November 2021, as the world’s first Earth science satellite to serve the United Nations 2030 Sustainable Development Agenda. A vicarious radiometric calibration experiment was conducted at the Dunhuang calibration site (Gobi Desert, China) on 14 December 2021. In-situ measurements of ground reflectance, aerosol optical depth (AOD), total columnar water vapor, radiosonde data, and diffuse-to-global irradiance (DG) ratio were performed to predict the top-of-atmosphere radiance by the reflectance-, irradiance-, and improved irradiance-based methods using the moderate resolution atmospheric transmission model. The MII calibration coefficients were calculated by dividing the top-of-atmosphere radiance by the average digital number value of the image. The radiometric calibration coefficients calculated by the three calibration methods were reliable (average relative differences: 2.20% (reflectance-based vs. irradiance-based method) and 1.43% (reflectance-based vs. improved irradiance-based method)). The total calibration uncertainties of the reflectance-, irradiance-, and improved irradiance-based methods were 2.77–5.23%, 3.62–5.79%, and 3.50–5.23%, respectively. The extra DG ratio measurements in the latter two methods did not improve the calibration accuracy for AODs ≤ 0.1. The calibrated MII images were verified using Landsat-8 Operational Land Imager (OLI) and Sentinel-2A MultiSpectral Instrument (MSI) images. The retrieved ground reflectances of the MII over different surface types were cross-compared with those of OLI and MSI using the FAST Line-of-sight Atmospheric Analysis of Hypercubes software. The MII retrievals differed by <0.0075 (7.13%) from OLI retrievals and <0.0084 (7.47%) from MSI retrievals for calibration coefficients from the reflectance-based method; <0.0089 (7.57%) from OLI retrievals and <0.0111 (8.65%) from MSI retrievals for the irradiance-based method; and <0.0082 (7.33%) from OLI retrievals and <0.0101 (8.59%) from MSI retrievals for the improved irradiance-based method. Thus, our findings support the application of SDGSAT-1 data.

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Section: Uncertainty Analysis Of Aod Retrievalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%