%0 Dataset
%T A long series surface freeze-thaw dataset of China - Decision tree algorithm (1987-2009)
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/8883a561-55b9-4b6d-a811-cfcb80d66898
%W NCDC
%R 10.12072/ncdc.westdc.db3783.2023
%A Jin rui
%A Li xin
%K Decision tree algorithm;Freeze-thaw
%X The Long-Series Surface Freeze-Thaw Dataset of China - Decision Tree Algorithm (1987-2009) was extracted by decision tree classification using passive microwave remote sensing SSM/I brightness temperature data.The dataset uses the EASE-Grid projection ( equal product cut cylindrical projection with ±30° standard latitude) with a spatial resolution of 25.067525km to provide a day-by-day classification of the surface freezing and thawing state of the main part of mainland China.The dataset is stored by year and consists of 23 folders in total, from 1987 to 2009.Each folder contains the day-by-day surface freeze-thaw classification results for the year as ASCII files with the naming convention:SSMI-frozenYYYY.txt, where YYYY stands for year and  stands for Julian day (001~365/366).The txt file of the freeze-thaw classification results can be opened directly by the text program, as well as by the ArcView + Spatial Analyst extension or the Asciigrid command of Arcinfo.The original data used to extract the surface freeze-thaw was derived from daily passive microwave data processed by the US National Snow and Ice Data Center (NSIDC) since 1987, using the EASE-Grid (Equivalent Area Expandable Earth Grid) as the standard format.The attributes of long series surface freeze-thaw dataset of China - Decision tree algorithm (1987-2009)  consist of the spatial and temporal resolution, projection information, and data format of this dataset.Temporal and spatial resolution: the temporal resolution is day-by-day, the spatial resolution is 25.067525km, the longitude range is 60° to 140°E and the latitude is 15° to 55°N.Projection information: global equiprobable cylindrical EASE-Grid projection. Detailed information on the EASE-Grid projection can be found in the description of this projection in the Data Preparation. Data format: The dataset consists of 23 folders from 1987 to 2009, each folder contains the day-by-day surface freeze-thaw classification results for that year, stored a