The 2016 suite of phenology metrics was derived from time-series Collection 6 Aqua eMODIS Normalized Difference Vegetation Index (NDVI) data. More information on Collection 6 processing can be found at https://lance3.modaps.eosdis.nasa.gov/. Users should be aware that the phenology data for 2001-2015 is based on time series Collection 5 Terra eMODIS NDVI data. It is known that these data were affected by deterioration in the MODIS instrument that was most pronounced after 2007. We plan to reprocess these phenology metrics using Collection 6 Aqua time series NDVI as soon as the appropriate funding can be allocated. Please contact us if you have questions or concerns.
In 2016, areas of No Data are shown over densely populated urban areas and areas where the soil has very high reflectance. We are currently performing an investigation on this phenomenon, however, we chose not to delay the release of this data. We currently believe that this may be an artifact of the Collect 6 Aqua eMODIS NDVI.