MODIS-derived NDVI Metrics
Summary
GINA and the National Park Service worked together to develop a MODIS-derived NDVI metrics algorithm. The data products from this project are available as 250m-resolution raster images of MODIS-derived yearly NDVI metrics. The data coverage includes the entire state of Alaska for the years between 2003 and 2020.
Data Sources
The NDVI metrics algorithm uses eMODIS data provided by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center. The data can be downloaded from the USGS-EROS eMODIS website.
Product Details
The algorithm takes 7-day composite eMODIS NDVI data, performs data stacking, interpolating, smoothing, and then calculates the NDVI metrics. 12 metrics are produced by the algorithm:
- Onset of greenness /Start day of Season (ONP)
- NDVI value of onset of greenness
- End of greenness /End day of Season (ENDP)
- NDVI value of end of greenness
- Duration of greenness – day range between onset of greenness and end of greenness
- Day with maximum NDVI
- Value of maximum NDVI
- Range of NDVI
- Rate of green up
- Rate of senescence
- Time-integrated NDVI
- Metrics ‘flag’, where -1=no data, 0=not valid data, 1=good data
The NDVI metrics algorithm technical document is available online.
The 12-band NDVI metrics are also available through GINA’s ftp server.
Sample Plots of the Metrics
Coming soon….
Acknowledgements
Amy E. Miller, Chuck Lindsay, Parker Martyn from National Park Service Anchorage for developing NDVI metrics algorithm
David K. Swanson for evaluation and feedback of NDVI metrics algorithm Ecologist, Arctic Network National Park Service
Michael E Budde for evaluation and feedback of NDVI metrics algorithm Geographer – US Geological Survey Earth Resources Observation and Science (EROS) Center
Calli B. Jenkerson for providing and explanation of eMODIS products MODIS SS NASA LPDAAC USGS EROS ERT Contractor to the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center http://lpdaac.usgs.gov