MODDIS Terra星MOD13A2 1KM 植被指数16天合成产品

全球MODIS植被指数是为了表现植被状况的时空综合特征而生产的。在生产MODIS植被指数的过程中，蓝、红、近红外反射率三个波段的数据被采用，三波段的中心分别为469nm, 、645 nm和858 nm。
MODIS NDVI（归一化植被指数）和NOAA先进型甚高分辨率辐射仪（AVHRR）的NDVI产品配合使用可以展示植被指数的时间序列变化。MODIS植被指数产品还包含一个新的植被指数，EVI（增强型植被指数）。EVI尽量减少了冠层背景结构的变化并保持了对植被密度状况的敏感性。EVI同样运用了蓝色波段去除由烟尘及小于一个像素的薄云等因素造成的大气污染残留。MODIS NDVI和EVI产品由经过水、云、重气溶胶、以及云阴影掩膜处理的双向大气校正表面反射率计算得来。
全球MOD13A2数据为16天合成的1000米L3数据产品，投影为正弦曲线投影。
植被指数可以用于全球植被指数监测，也可以用在显示地表覆盖或者地表覆盖变化的产品中，还可以用作全球生物地球化学和水文模型或者全球或地区气候等模型的输入数据，还可以用于描述陆地表面的生物物理特征及进程，包括初级生产以及陆地表面覆盖的转换。

The Global MODIS Vegetation Indices are produced to characterize the spatiotemporal comprehensive features of vegetation conditions. In the production process of MODIS vegetation indices, data from three bands including blue, red, and near-infrared reflectance are adopted, with central wavelengths of 469 nm, 645 nm, and 858 nm respectively.

When used in conjunction with the NDVI products from NOAA Advanced Very High Resolution Radiometer (AVHRR), MODIS NDVI (Normalized Difference Vegetation Index) can demonstrate the temporal sequence changes of vegetation indices. The MODIS vegetation index product suite also includes a new vegetation index, EVI (Enhanced Vegetation Index). EVI minimizes variations in canopy background structure while retaining sensitivity to vegetation density conditions. Additionally, EVI employs the blue band to eliminate residual atmospheric contamination caused by factors such as smoke and thin clouds smaller than one pixel. MODIS NDVI and EVI products are calculated from bidirectionally atmospherically corrected surface reflectance that has undergone masking for water, clouds, heavy aerosols, and cloud shadows.

The global MOD13A2 dataset is a 16-day composite 1000-meter Level 3 data product, with its projection being Sinusoidal Projection.

Vegetation indices can be utilized for global vegetation index monitoring, as well as in products displaying land cover or land cover changes. They can also serve as input data for global biogeochemical and hydrological models, or models such as global or regional climate models, and can be applied to describe the biophysical characteristics and processes of the terrestrial surface, including primary production and land cover conversion.