Science Center Objects

The sensor responsible for the longest running series of NDVI products used for large-area phenology studies is carried aboard National Oceanic and Atmospheric Administration (NOAA) polar-orbiting weather satellites (see Table 1). This sensor, known as the Advanced Very High Resolution Radiometer (AVHRR), has a daily repeat cycle and, despite its name, a 1-km resolution (an AVHRR image pixel represents 1 square km of land surface). AVHRR data are used to generate NDVI-based images of the planet's land surface on a regular basis, thereby creating image series that portray seasonal and annual changes to vegetation worldwide. AVHRR NDVI data are available in a consistently processed database from 1982-present at an 8-km re-sampling grid covering the entire planet, and from 1989-present at a 1-km resolution for the conterminous United States. 


Phenology - NDVI from AVHRR table

Table 1.  Low or no-cost satellite sensors and data streams utilized for land surface phenology studies1

1  Data sets are accessible for low- or no-cost for use in phenology research and applications (as of 1/4/2011).
2  USGS Earth Explorer: (https://earthexplorer.usgs.gov/)
3  GIMMS data set: (https://ecocast.arc.nasa.gov/data/pub/gimms/3g.v0/)
4  Flemish Institute for Technology Research (VITO) for SPOT Vegetation S10 products:  (http://www.spot-vegetation.com and http://free.vgt.vito.be
5  Land Processes Distributed Active Archive Center: (https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table)
6  eMODIS: (https://dds.cr.usgs.gov/emodis/), Latency is approximately 15 hours for expedited data (released daily) and around 7 days for historical data.

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