摘要：this paper describes a set of Near-Real-time (NRt) Vegetation Index (VI) data products for the Conterminous United States (CONUS) based on Moderate Resolution Imaging Spectroradiometer (MODIS) data from Land, Atmosphere Near-real-time Capability for EOS (LANCE), an openly accessible NASA NRT Earth observation data repository. The data set ofers a variety of commonly used VIs, including Normalized Diference 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 . With more than 20 years of observations, this continuous data set enables geospatial time series analysis and change detection in many research felds such as agricultural monitoring, natural resource conservation, environmental modeling, and Earth system science . The complete set of VI data products described in the paper is openly distributed via Web Map Service (WMS) and Web Coverage Service (WCS) as well as the VegScape web application (https://nassgeodata.gmu.edu/VegScape/) .
