MYDDIS Aqua星MYD13A3 1KM 月植被指数L3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 MYD13A3数据为月合成的1000米L3数据产品，投影为正弦曲线投影。产生MYD13A3月数据产品的过程中，系统算法比较一月中所有的16天合成1公里产品，如果都是无云数据，给一个权重得到临时平均值，如果有云的影响，取最大值。
全球MYD13A2数据为16天合成的1000米L3数据产品，投影为正弦曲线投影。VI产品在Terra星和Aqua星数据分不同时间段进行计算，Terra星数据从每年的第1天开始，Aqua星数据从每年的第8天开始。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 spatio-temporal comprehensive features of vegetation conditions. In the production process of MODIS vegetation indices, data from three bands of blue, red, and near-infrared reflectance are adopted, with central wavelengths of 469 nm, 645 nm, and 858 nm respectively.

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

The global MYD13A3 dataset is a monthly composite 1000-meter L3 data product with a Sinusoidal projection. In the generation process of the MYD13A3 monthly data product, the system algorithm compares all 16-day composite 1-kilometer products within a month. If all products are cloud-free, a weighted temporary average is calculated; if cloud contamination exists, the maximum value is adopted instead.

The global MYD13A2 dataset is a 16-day composite 1000-meter L3 data product with a Sinusoidal projection. VI products are calculated using data from the Terra and Aqua satellites over different time periods: Terra satellite data starts from the 1st day of each year, while Aqua satellite data starts from the 8th day of each year. Vegetation indices can be used 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, hydrological, or global/regional climate models, and be utilized to describe biophysical characteristics and processes of the terrestrial surface, including primary production and land cover conversion.

搜集汇总

背景与挑战

背景概述

该数据集是Aqua卫星的MYD13A3月合成植被指数L3产品，空间分辨率为1公里，使用正弦曲线投影，基于蓝、红、近红外波段计算NDVI和EVI指数，并经过大气校正和云掩膜处理。它主要用于全球植被监测、地表覆盖变化分析，以及作为生物地球化学和水文模型的输入数据，具有高精度和广泛的应用价值。