GHS-composite-S2 R2020A - Sentinel-2 global pixel based image composite from L1C data for the period 2017-2018

GHS-composite-S2 R2020A corresponds to global cloud-free pixel based composite created from the Sentinel-2 data archive (Level L1C) available in Google Earth Engine for the period January 2017- December 2018. GHS_composite_S2_L1C_2017-2018_GLOBE_R2020A: pixel based image composite. It consists of a global scale raster grid of four spectral bands (B2: Blue, B3: Green, B4: Red and B8: Near Infrared) with a spatial resolution of 10 meters. It is produced and tiled following the Universal Transverse Mercator (UTM) system with each tile having the projection of the UTM zones (UTM/WGS84 projection) to which it corresponds to. This dataset has been used as the core input data for the update of the Global Human Settlement Layer (GHS-BUILT) by mapping built-up areas at a spatial resolution of 10 meters . GHS_DOY_S2_L1C_2017-2018_GLOBE_R2020A raster grid at 10 meter resolution representing the Day of the Year (DOY) of the images contributing the Sentinel-2 image composite

GHS-composite-S2 R2020A对应于基于全球无云像素的合成影像，其数据源为2017年1月至2018年12月期间谷歌地球引擎（Google Earth Engine）中可用的哨兵2号（Sentinel-2）L1C级数据档案。

GHS_composite_S2_L1C_2017-2018_GLOBE_R2020A：基于像素的合成影像。它包含一个全球尺度的栅格网格，涵盖4个光谱波段（B2：蓝色、B3：绿色、B4：红色、B8：近红外），空间分辨率为10米。

该数据集的生成与分块遵循通用横轴墨卡托投影系统（Universal Transverse Mercator，UTM），每个分块采用其对应UTM分区的投影（UTM/WGS84投影）。

该数据集已被用作全球人类聚居层（Global Human Settlement Layer，GHS-BUILT）更新的核心输入数据，用于绘制空间分辨率为10米的建成区地图。GHS_DOY_S2_L1C_2017-2018_GLOBE_R2020A是一个10米分辨率的栅格网格，代表构成哨兵2号合成影像的各单景影像的年积日（Day of the Year，DOY）。