Normalised Difference Vegetation Index Statistics (Long Term 1999-2019 / Short Term 2015-2019) (raster 1 km), global, 10-daily - version 3

The Normalised Difference Vegetation Index (NDVI) is a widely used, dimensionless index that is indicative for vegetation density and is defined as NDVI=(NIR-Red)/(NIR+Red) where NIR corresponds to the reflectance in the near infrared bands, and Red to the reflectance in the red bands. The time series of 10-daily NDVI 1km version 3 observations is used to calculate Long Term Statistics (LTS), over the 20-year period 1999-2019, and Short Term Statistics (STS), over the 5-year period (2015-2019), for each of the 36 10-daily periods (dekads) of the year. The calculated statistics include the minimum, median, maximum, mean, standard deviation and the number of observations in the covered time series period. These statistics can be used as a reference for actual NDVI observations, which allows monitoring of anomalous vegetation conditions.

归一化差分植被指数（Normalised Difference Vegetation Index, NDVI）是一种应用广泛的无量纲指数，可用于表征植被密度，其定义为NDVI=(NIR-Red)/(NIR+Red)，其中NIR对应近红外波段的反射率，Red对应红波段的反射率。本数据集采用1999-2019年共20年时段的10天合成1km分辨率第3版NDVI时间序列观测数据，针对每年的36个10天周期（即旬），分别计算长期统计量（Long Term Statistics, LTS）与短期统计量（Short Term Statistics, STS）：长期统计量基于1999-2019年的20年时段，短期统计量基于2015-2019年的5年时段。所计算的统计量包括最小值、中位数、最大值、平均值、标准差，以及对应覆盖时段内的观测样本总数。此类统计量可作为实际NDVI观测值的参考基准，用于监测植被异常状况。