eMODIS

eMODIS provides annual (1 value per year per grid cell) phenological metrics at 250 m resolution from 2001 to present based on an analysis of a time series of the Normalized Difference Vegetation Index (NDVI) for a given year from satellite imagery captured from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite. DEVISE includes the following variables: Start of season time (day of year denoting the start of measurable photosynthesis activity), Maximum time (day of year where photosynthesis activity peaked), End of season time (day of year denoting the end of measurable photosynthesis activity), Duration (number of days where photosynthetic activity is detected), and Time Integrated NDVI (a metric of cumulative photosynthetic activity for the year). Methods used to develop Emodis metrics can be found here.

Start of season time (SOST)

Beginning of measurable photosynthesis in the vegetation canopy (day of year). Calculated on a cell by cell basis on a single temporal scale (annually) with the statistics max, mean, and median.

Maximum Time (MAXT)

Time of maximum photosynthesis in the canopy (day of year). Calculated on a cell by cell basis on a single temporal scale (annually) with the statistics max, mean, and median.

End of Season Time (EOST)

End of measurable photosynthesis in the vegetation canopy (day of year). Calculated on a cell by cell basis on a single temporal scale (annually) with the statistics max, mean, and median.

Duration (DUR)

Length of photosynthetic activity (number of days). Calculated on a cell by cell basis on a single temporal scale (annually) with the statistics max, mean, and median.

Time Integrated NDVI (TIN)

Canopy photosynthetic activity across the entire growing season (interpolated NDVI). Calculated on a cell by cell basis on a single temporal scale (annually) with the statistics max, mean, and median.