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A fast cloud detection algorithm applicable to monitoring and nowcasting of daytime cloud systems / Xiao-Yong Zhuge in IEEE Transactions on geoscience and remote sensing, vol 55 n° 11 (November 2017)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 55 n° 11 (November 2017) . - pp 6111 - 6119 Titre : A fast cloud detection algorithm applicable to monitoring and nowcasting of daytime cloud systems Type de document : Article/Communication Auteurs : Xiao-Yong Zhuge, Auteur ; Xiaolei Zou, Auteur ; Yuan Wang, Auteur Année de publication : 2017 Article en page(s) : pp 6111 - 6119 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] détection des nuages [Termes IGN] Himawari Résumé : (Auteur) The Advanced Himawari Imager (AHI) onboard Japanese geostationary satellite Himawari-8 provides two more visible, three more near-infrared, and six more infrared channels than the only one visible and four infrared channels available from the previous geostationary imager instruments. By taking advantage of AHI's newly added channels 1, 3, and 4 with wavelengths centered at 0.46, 0.64, and $0.86 μm, respectively, a fast cloud detection algorithm is developed. Since the spectral differences of the reflectance between any two of AHI's channels 1, 3, and 4 over clouds are smaller than those over land and ocean, a visible-based cloud index (VCI) for daytime cloud detection can thus be defined by the root mean square of the three differences between any two of these three channels. An AHI pixel is identified as cloudy if the VCI is smaller than a threshold, which has different values over ocean and land. Cloud detection is further adjusted by a bias correction using AHI channels 7 and 13. The average accuracy of the proposed simple cloud detection is comparable with those obtained from a more complicated cloud mask algorithm involving not only more channels but also model simulations. It is also found that the bias correction is needed mostly over cirrus clouds and Gobi. Numéro de notice : A2017-743 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2017.2720664 En ligne : https://doi.org/10.1109/TGRS.2017.2720664 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88777 [article]