MODIS Terra星MOD13Q1 250M 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每日植被指数的过程中，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MOD13Q1数据为16 天合成的250米L3数据产品，投影为正弦曲线投影。因为没有250米的蓝色波段，EVI算法利用500米的蓝色波段来矫正气溶胶的影响，会有一些微小的空间变形。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。 (协议共享)The global MODIS Vegetation Index (VI) products are developed to characterize the spatiotemporal features of vegetation conditions. When generating the MODIS daily vegetation index, data from three spectral bands—blue, red, and near-infrared reflectance—are used, with central wavelengths of 469 nm, 645 nm, and 858 nm respectively. The MODIS NDVI (Normalized Difference Vegetation Index) products, when paired with the NDVI products from the NOAA Advanced Very High Resolution Radiometer (AVHRR), can reveal the temporal variations of vegetation indices. The MODIS VI products also include a new vegetation index, EVI (Enhanced Vegetation Index). EVI minimizes variations in canopy background structure while maintaining sensitivity to vegetation density conditions. Additionally, EVI utilizes the blue band to eliminate residual atmospheric contamination caused by factors such as soot and thin clouds smaller than one pixel. Both MODIS NDVI and EVI products are calculated from bidirectional atmospherically corrected surface reflectance that has been masked for water, clouds, heavy aerosols, and cloud shadows. The global MOD13Q1 dataset is a 16-day composite 250-meter Level 3 data product with a Sinusoidal projection. Since no 250-meter blue band is available, the EVI algorithm uses the 500-meter blue band to correct for aerosol effects, which may introduce minor spatial distortions. Vegetation indices have broad applications, including global vegetation monitoring, land cover or land cover change mapping products, serving as input data for global biogeochemical, hydrological, and global/regional climate models, and characterizing biophysical features and processes of the terrestrial surface such as primary production and land cover conversion. (Shared under agreement)

搜集汇总

背景与挑战

背景概述

该数据集是MODIS Terra卫星的MOD13Q1产品，提供全球250米空间分辨率的植被指数数据，每16天合成一次，包含归一化植被指数（NDVI）和增强型植被指数（EVI），其中EVI通过蓝色波段减少大气污染影响以提高精度。数据采用正弦曲线投影，适用于全球植被监测、地表覆盖变化分析和生物地球化学模型输入。