|U.S. Department of Agriculture
National Agricultural Statistics Service
Research and Development Division
of the Director
The Vegetation Condition data
selectable below are updated weekly and arranged by two week composite periods covering
the 1995 - 1999, 2001-2003, 2004-2009, 2010, and 2011 (as available) crop
seasons. A water vapor correction was applied by USGS to
data collected by NOAA-14 from the 1995 through the 1999 crop season.
Data from subsequent satellites (NOAA-16, NOAA-17) are not water vapor
corrected. Ratio derived products of a specific period to a previous comparable
date period are only created within images of the same satellite.
The NOAA-16 satellite collected images from the 2001 through 2003 seasons. NOAA-16 started malfunctioning in early 2004, when a scan motor problem caused a 'barcode' appearance. Images from the NOAA-17 satellite replaced NOAA-16 starting in 2004. The USGS released updated calibration coefficients for the NOAA-17 satellite developed by NOAA after the 2004 growing season. Images available below from the 2004 - 2009 growing seasons reflect the updated calibration coefficients. In February 2011, the AVHRR NOAA-17 sensor began having scan motor problems that affected data quality. Effective March 2011, NOAA-18 will be the new vegetative condition monitoring satellite. Animations of these images for a given year reveal how the vegetation condition changed during that growing season.