Monthly Global NDVI at 5 km based on AVHRR product - 1982 to 2019 (Q6688946)

Long-term monthly NDVI calculated through daily images of AVHRR (NOAA/CDR/AVHRR/NDVI/V5), which were cloud screened and aggregated by percentile 90th onGoogle Earth Engine-GEE. All the images were exported from GEE to R environment where the follow procedures were executed on a pixel-basis: Outlier removalbased on a temporal moving window, used to identify and remove NDVI outlier values (i.e.greater or less than 1.5 standard deviation calculated on 60-months time window) Smoothing and gap fillingapproach implemented by thegreenbrown package(TSGFssa method) The final product is composed by 456 NDVI global images without gaps and for each month was producedan ancillary image indicating: Disregarded pixels: -25000 (removed)and -32000 (nodata) Gapfilled pixels: -20000 Smoothed pixels: all values greater than -20000 indicate the difference between the original and smoothed AVHHR NDVI To access and visualize the maps use:OpenLandMap.org Publication in preparation. All files were internally compressed using COMPRESS=DEFLATE creation option in GDAL. File naming convention(veg_ndvi_avhrr_p90_5km_s0..0cm_20000101..20000131 _v1.0): veg = Vegetation theme ndvi = Normalized Difference Vegetation Index avhrr = NOAA CDR AVHRR V5product p90 = Percentile 90th to aggregate the daily images 5km = 5 km of spatial resolution s0..0cm = land surface as vertical reference 20000101..20000131 = from 2000-01-01 to 2000-01-31 (time reference) v1.0 = version number