Near-real-time MODIS-derived vegetation index data products for CONUS (sample data)

This is a Near-Real-Time (NRT) Vegetation Index (VI) data set for the Conterminous United States (CONUS) based on MODIS data from Land, Atmosphere Near-real-time Capability for EOS (LANCE), an openly accessible NASA near-real-time EO data repository. The data set includes a variety of commonly used VIs including Normalized Difference Vegetation Index (NDVI), Vegetation Condition Index (VCI), Mean-referenced Vegetation Condition Index (MVCI), Ratio to Median Vegetation Condition Index (RMVCI), and Ratio to Previous-year Vegetation Condition Index (RVCI). LANCE enables the NRT monitoring of U.S. cropland vegetation conditions within 24 hours of observation. Meanwhile, this continuous data set with more than 20 years of vegetation condition observation would be suitable for time series analysis and change detection in many research fields such as agriculture, remote sensing, geographical information science and systems, environmental modeling, and Earth system science.<br>This dataset includes a collection of sample VI data products, including daily NDVI from 6/7/2021 to 6/13/2021, and weekly/biweekly NDVI, VCI, MVCI, RMVCI, RVCI for week 23 in 2021. The complete dataset is free to access through the VegScape web application (https://nassgeodata.gmu.edu/VegScape/) as well as distributed via Web Map Service and Web Coverage Service (https://nassgeo.csiss.gmu.edu/VegScape/devhelp/help.html).

本数据集为基于美国国家航空航天局（National Aeronautics and Space Administration, NASA）公开可访问的近实时地球观测（Earth Observation, EO）数据仓库EOS陆地大气近实时能力（Land, Atmosphere Near-real-time Capability for EOS, LANCE）所提供的中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）数据，构建的美国本土（Conterminous United States, CONUS）近实时（Near-Real-Time, NRT）植被指数（Vegetation Index, VI）数据集。该数据集涵盖多种常用植被指数，具体包括归一化差分植被指数（Normalized Difference Vegetation Index, NDVI）、植被状况指数（Vegetation Condition Index, VCI）、均值参考植被状况指数（Mean-referenced Vegetation Condition Index, MVCI）、中值比值植被状况指数（Ratio to Median Vegetation Condition Index, RMVCI）以及上年同期植被状况指数（Ratio to Previous-year Vegetation Condition Index, RVCI）。LANCE可在观测完成后的24小时内实现美国农田植被状况的近实时监测。与此同时，这套拥有20余年植被状况观测记录的连续型数据集，可广泛应用于农业、遥感、地理信息科学与系统、环境建模以及地球系统科学等多个研究领域的时间序列分析与变化检测。<br>本数据集包含一组植被指数样本数据产品，具体包括2021年6月7日至6月13日的日尺度NDVI，以及2021年第23周的周/双周尺度NDVI、VCI、MVCI、RMVCI和RVCI。完整数据集可通过VegScape网页应用（https://nassgeodata.gmu.edu/VegScape/）免费获取，同时也可通过网络地图服务（Web Map Service, WMS）与网络覆盖服务（Web Coverage Service, WCS）进行分发，相关帮助文档可参考https://nassgeo.csiss.gmu.edu/VegScape/devhelp/help.html。