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eMODIS (EROS Moderate Resolution Imaging Spectroradiometer)

   

The MODIS NDVI V6 collection uses the AQUA MODIS sensor only, the TERRA MODIS sensor is not included.  We are now posting historical and expedited eMODIS composites built from Collection 6 surface reflectance data.

 As a warning to users, we have noted a problem with the NDVI where occasional high NDVI spikes appear  that were not present in the Collection 5 NDVI.  The high NDVI spikes have been traced back to processing of daily level 2 Collection 6 surface reflectance where a minimum blue band correction leads to selecting an observation with very low red reflectance that then magnifies the NDVI. Our eMODIS code selects for high NDVI values during a composite period.

 

Moderate resolution remote sensing provides a means for operational monitoring communities to develop historical trend information and use near real-time deviations from temporal averages to identify areas of change. High quality, consistent and well-calibrated satellite measurements are needed to detect and monitor changes and trends, especially in vegetation patterns useful for drought, crop yield, phenology and fire potential studies.

The eMODIS collection is based on the Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired by the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS). Even though MODIS data are beneficial in vegetation studies, there have been usability issues encountered with the reprojection, file format and subsetting. Therefore, eMODIS was developed to specifically address these issues.

The eMODIS suite of products includes either 7- or 10-day data composited data sets. Expedited (near real-time) production runs daily for the 7-day continental U.S. products and every five days for the 10-day products in other areas using the last interval of input. There is no expedited production over Alaska. Each data set delivers acquisition, quality and Normalized Difference Vegetation Index (NDVI) information at 250-meter (m) spatial resolution.   Because each of the composites are created from a varying number of images, the eMODIS composites include acquisition files to identify which of the possible inputs were used to populate the final composite. The metadata accompanying the data files summarize geographic bounds, projection parameters and product contact information.

eMODIS currently produces NDVI and reflectance over the continental U.S., Alaska and Central America/Caribbean and Mexico while Africa and Central Asia production contain NDVI only.

Digital Products

The products are generated for Aqua MODIS over all areas including continental U.S. and Alaska and are projected to a regionally specific mapping grid and delivered in a compressed (zipped) GeoTIFF format.

Coverage Maps

Coverage Maps indicating the availability of eMODIS NDVI products are available for download.

Additional Information:

Data Use and Citation Policies

For information on how to cite USGS data plus guidance on usage restrictions,
please see our Data Citations and Use page at https://lta.cr.usgs.gov/citation.

Any use of trade, firm, or product names is for descriptive purposes only and
does not imply endorsement by the U.S. Government.

Contact Information for User Assistance

Long Term Archive User Services
U.S. Geological Survey (USGS)
Earth Resources Observation and Science (EROS) Center
47914 252nd Street
Sioux Falls, SD 57198-0001

Phone Number: 605-594-6151
Toll Free: 800-252-4547
Fax: 605-594-6589

Email:lta@usgs.gov
Web: https://lta.cr.usgs.gov

Business Hours: Monday thru Friday, 8:00 a.m. to 4:00 p.m., Central Time