%0 Dataset
%T China AVHRR Daily Cloudless 5 km Snow Area Product Dataset
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/b84eefb4-b6eb-45bf-9ff0-4198ffdd49d1
%W NCDC
%R 10.12072/ncdc.I-SNOW.db0005.2020
%A Xiaohua Hao 
%A Ji Wenzheng
%A Zhao Qin
%A Sun Xingliang
%A Wangjian
%A Li Hongyi
%K AVHRR;snow area;cloud removal;daily;long time series
%X Snow cover is an important component of the cryosphere, and its coverage affects the energy balance between the Earth and the atmosphere, thereby affecting climate and environmental changes. Snow cover area is one of the important snow cover parameters and an important input for hydrological and climate models. This dataset focuses on the characteristics of snow cover in China and is based on the AVHRR-CDR reflectance product. A multi-level decision tree snow discrimination algorithm has been developed. At the same time, hidden Markov algorithm and multi-source data fusion method have been used to achieve complete cloud removal of the product. A daily cloudless snow cover area dataset with a spatial resolution of 5 km from 1980 to 2020 has been prepared. This dataset is stored in the HDF5 file format, with each HDF5 file containing 18 data elements, including data values, data start dates, longitude and latitude, etc. At the same time, in order to quickly preview the distribution of snow cover, the daily file contains thumbnail images of the snow cover area, stored in jpg format. The dataset also includes a user manual for ease of use. This dataset will be continuously supplemented and improved based on real-time satellite remote sensing data and algorithm updates (as of December 2020), and will be fully open and shared