GEOGRAPHIC INFORMATION

Normal for Monthly NDVI for Year 2000 to Present from TERRA

Data Provider Montana Climate Office
Date 01/01/2003 - 01/01/2013
Content Type Downloadable Data
Abstract Normals represent the average condition over a given period of time. The mean and standard deviation of monthly Normalized Difference Vegetation Index (NDVI) are derived and used to calculate the departure from normal as a z-score for year 2000 to present. The Normalized Difference Vegetation Index (NDVI) is an index of plant “greenness” or photosynthetic activity, and is one of the most commonly used vegetation indices. Vegetation indices are based on the observation that different surfaces reflect different types of light differently. Photosynthetically active vegetation, in particular, absorbs most of the red light that hits it while reflecting much of the near infrared light. Vegetation that is dead or stressed reflects more red light and less near infrared light. Likewise, non-vegetated surfaces have a much more even reflectance across the light spectrum. By taking the ratio of red and near infrared bands from a remotely-sensed image, an index of vegetation “greenness” can be defined. Starting 2000, and after the launch of the two MODIS sensors on the Terra and Aqua satellites by NASA, NDVI was adopted as a standard product. The Terra satellite collection encompasses the years 2000 to present. The Aqua satellite collection encompasses the years 2002 to present. The Montana Climate Office transforms the source MODIS datasets from their native sinusoidal projection to the Montana State Plane coordinate system for the area-of-interest for both the Aqua and Terra MODIS platforms. Technical details for MODIS can be found in the user guide posted at ftp://mco.cfc.umt.edu/resources/MCO/Papers/MODIS_VI_UsersGuide_01_2012.pdf
Purpose The mean for monthly Normalized Difference Vegetation Index (NDVI) for Montana is provided in gridded format. The Normalized Difference Vegetation Index (NDVI) is probably the most common of these ratio indices for vegetation. The biophysical interpretation of NDVI is the fraction of absorbed photosynthetically active radiation. Many factors affect NDVI values like plant photosynthetic activity, total plant cover, biomass, plant and soil moisture, and plant stress. Because of this, NDVI is correlated with many ecosystem attributes that are of interest to researchers and managers (e.g., net primary productivity, canopy cover, bare ground cover). Also, because it is a ratio of two bands, NDVI helps compensate for differences both in illumination within an image due to slope and aspect, and differences between images due things like time of day or season when the images were acquired. Thus, vegetation indices like NDVI make it possible to compare images over time to look for ecologically significant changes.
Supplemental Information Processed from HDF raster file source using Python 2.7 code maintained by the Montana Climate Office.
The Montana Climate Office (MCO) provides this product/service for informational purposes only. The MCO did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should rndview or consult the primary data and information sources to ascertain the viability of the information for their purposes. The MCO provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the MCO be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The MCO makes these data and services available as a convenience to the public, and for no other purpose. The MCO reserves the right to change or rndvise published data and/or services at any time.
Data Access ftp://mco.cfc.umt.edu/ndvi/terra/monthly_normals/Readme.html
Distributor Michael D. Sweet Research and Information Systems Specialist Montana Climate Office
32 Campus Drive
Missoula, Montana 59812-0576
Telephone: 406.243.5265
TDD/TTY:
Fax:
Email: michael.sweet@umontana.edu
Distribution liability The Montana Climate Office (MCO) provides this product/service for informational purposes only. The MCO did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should rndview or consult the primary data and information sources to ascertain the viability of the information for their purposes. The MCO provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the MCO be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The MCO makes these data and services available as a convenience to the public, and for no other purpose. The MCO reserves the right to change or rndvise published data and/or services at any time.
View Metadata
View Metadata (XML)
Metadata date 02/13/2015

Page History