Enhanced Vegetation Index

The Enhanced Vegetation Index is derived from the MODIS MCD43D62, MCD43D63 and MCD43D64 v6.1 products. EVI is first calculated on the datasets using the formula from Huete et al (2002) and then the outputs are gap-filled using the approach outlined in Weiss et al (2014) to eliminate missing data caused by factors such as cloud cover.

The gap-filled 8-daily ~1km outputs are then aggregated temporally and spatially to produce monthly and annual ~5km products.

Directories are structured in the following way: EVI_v061/{Resolution}/{TemporalSummary}

And under that, filenames are structured by:
8-daily: EVI_v061.{Year}.{JulianDay}.Data.{Resolution}.{SpatialSummary}.tif
Monthly: EVI_v061.{Year}.{Month}.{TemporalSummary}.{Resolution}.{SpatialSummary}.tif
Annual: EVI_v061.{Year}.Annual.{TemporalSummary}.{Resolution}.{SpatialSummary}.tif
Synoptic: EVI_v061.Synoptic.{Month-or-Overall}.{TemporalSummary}.{Resolution}.{SpatialSummary}.tif

Resolution in this dataset is either 1km or 5km

Standard values for TemporalSummary are: min, max, range, mean, SD, count. In addition there are:

• Data: this indicated that no temporal aggregation has occurred
• Balanced-mean: This is specific to overall synoptic data, it represents the mean of the 12 monthly synoptic mean datasets as opposed to the overall mean of the (e.g. daily) data. This gives a weighting to help correct for seasonal bias that could otherwise be present in areas where data are more often missing at certain times of year.

Standard values for SpatialSummary are: min, max, range, sum, mean, SD, count. In addition:

• Data: this indicates that no spatial aggregation has occurred