Temporal Coverage: 30 July 2016 - present
Vegetation indices are used for monitoring of vegetation conditions and can be used to identify areas undergoing land cover changes. These data may be used as input for modeling global biogeochemical and hydrologic processes and global and regional climate. These data also may be used for characterizing land surface biophysical properties and processes including primary production and land cover conversion. Vegetation indices also provide information on the health of vegetation and can assist farmers and resource managers monitor the health and development of their crops and fields over the growing season.
The MODIS Normalized Difference Vegetation Index (NDVI) layer is a measure of the greenness and health of vegetation. The index is calculated based on how much red and near-infrared light is reflected by plant leaves. The index values range from -0.2 to 1 where higher values (0.3 to 1) indicate areas covered by green, leafy vegetation and lower values (0 to 0.3) indicate areas where there is little or no vegetation. Areas with a lot of green leaf growth, indicates the presence of chlorophyll which reflects more infrared light and less visible light, are depicted in dark green colors, areas with some green leaf growth are in light greens, and areas with little to no vegetation growth are depicted in tan colors.
The MODIS rolling 8-day NDVI layer is available as a near real-time, rolling 8-day product (MOD13Q4N) from from the Terra satellite. It is created from a rolling 8-day land surface reflectance product, MOD09Q1N. The sensor resolution is 250 m, imagery resolution is 250 m, and the temporal resolution is an 8-day product which is updated daily.
The MODIS Enhanced Vegetation Index (EVI) is also used as a measure of the greenness and health of vegetation. It is calculated in a similar fashion as NDVI but it corrects for distortions caused by ground cover beneath the canopy vegetation and distortions in reflected light caused by particles in the air by using the blue band to remove residual atmosphere contamination caused by smoke and sub-pixel thin cirrus clouds. The EVI is more effective in areas with large amounts of chlorophyll such as rainforests. The index values range from -0.2 to 1 where higher values (0.3 to 1) indicate areas covered by green, leafy vegetation and lower values (0 to 0.3) indicate areas where there is little or no vegetation.
The MODIS rolling 8-day EVI layer is available as a near real-time, rolling 8-day product (MOD13Q4N) from from the Terra satellite. It is created from a rolling 8-day land surface reflectance product, MOD09Q1N. The sensor resolution is 250 m, imagery resolution is 250 m, and the temporal resolution is an 8-day product which is updated daily.
References: NASA Earth Observatory - Measuring Vegetation; NASA Earthdata - New Vegetation Indices and Surface Reflectance Products Available from LANCE; NASA NEO - Vegetation Index
Temporal coverage: 4 March 2000 - present (Terra); July 2002 - present (Aqua)
The Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices (MOD13Q1/MYD13Q1) Version 6 data are generated every 16 days at 250 meter (m) spatial resolution as a Level 3 product. The MOD13Q1/MYD13Q1 product provides Normalized Difference Vegetation Index (NDVI) which is referred to as the continuity index to the existing National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR) derived NDVI. The algorithm chooses the best available pixel value from all the acquisitions from the 16-day period. The criteria used is low clouds, low view angle, and the highest NDVI value.
Reference: LP DAAC - MOD13Q1 Version 6; LP DAAC - MYD13Q1 Version 6
Temporal coverage: February 2000 - present (Terra); July 2002 - present (Aqua)
The Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices (MOD13A3/MYD13A3) Version 6 data are provided monthly at 1 kilometer (km) spatial resolution as a gridded Level 3 product in the sinusoidal projection. In generating this monthly product, the algorithm ingests all the Terra/Aqua MODIS Vegetation Indices 16-day products that overlap the month and employs a weighted temporal average.
The MODIS Normalized Difference Vegetation Index (NDVI) complements NOAA's Advanced Very High Resolution Radiometer (AVHRR) NDVI products and provides continuity for time series historical applications. The MODIS NDVI product is computed from surface reflectances corrected for molecular scattering, ozone absorption, and aerosols.
Vegetation indices are used for global monitoring of vegetation conditions and are used in products displaying land cover and land cover changes. These data may be used as input for modeling global biogeochemical and hydrologic processes as well as global and regional climate. Additional applications include characterizing land surface biophysical properties and processes, such as primary production and land cover conversion.
Reference: Reference: LP DAAC - MOD13A3 Version 6; LP DAAC - MYD13A3 Version 6
Temporal coverage: 4 March 2000 - present (Terra); 3 July 2002 - present (Aqua)
The Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices (MOD13Q1/MYD13Q1) Version 6 data are generated every 16 days at 250 meter (m) spatial resolution as a Level 3 product. The MOD13Q1/MYD13Q1 product provides the Enhanced Vegetation Index (EVI), which has improved sensitivity over high biomass regions. The algorithm chooses the best available pixel value from all the acquisitions from the 16-day period. The criteria used is low clouds, low view angle, and the highest EVI value.
Reference: LP DAAC - MOD13Q1 Version 6; LP DAAC - MYD13Q1 Version 6
Temporal coverage: February 2000 - present (Terra); July 2002 - present (Aqua)
The Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Indices (MOD13A3/MYD13A3) Version 6 data are provided monthly at 1 kilometer (km) spatial resolution as a gridded Level 3 product in the sinusoidal projection. In generating this monthly product, the algorithm ingests all the Terra/Aqua MODIS Vegetation Indices 16-day products that overlap the month and employs a weighted temporal average.
The Enhanced Vegetation Index (EVI) minimizes canopy background variations and maintains sensitivity over dense vegetation conditions. The EVI uses the blue band to remove residual atmosphere contamination caused by smoke and sub-pixel thin clouds. The MODIS EVI product is computed from surface reflectances corrected for molecular scattering, ozone absorption, and aerosols.
Vegetation indices are used for global monitoring of vegetation conditions and are used in products displaying land cover and land cover changes. These data may be used as input for modeling global biogeochemical and hydrologic processes as well as global and regional climate. Additional applications include characterizing land surface biophysical properties and processes, such as primary production and land cover conversion.
Reference: LP DAAC - MOD13A3 Version 6; LP DAAC - MYD13A3 Version 6