ESOP 1995 Land Cover (vegetation) Imagery
     
     1.0  General Description
     
          The United States Geological Survey (USGS) Earth Resources
     Observation System (EROS) Data Center Land Cover (vegetation) imagery
     is one of several image datasets provided in the GEWEX Continental-Scale
     International Project (GCIP) Enhanced Seasonal Observing Period (ESOP)
     1995. The Land Cover imagery covers the conterminous United States. 
     The Land Cover imagery contains bi-weekly composites for a six month
     period encompassing the entire ESOP 1995 time period (01 April 1995
     through 30 September 1995).  
     
     2.0  Detailed Data Description
     
          The USGS EROS Data Center routinely ingested 1-km resolution
     satellite data from the Advanced Very High Resolution Radiometer
     (AVHRR) and produced bi-weekly vegetation index imagery.  The
     seasonal land cover regions have unique combinations of vegetation
     mosaics, seasonal properties (onset, peak, and length of green period),
     and annual primary production. The regions are grouped into general land
     cover types; increasing color intensity within each group corresponds to
     increasing primary production. These land cover types include western
     forests, shrublands, alpine tundra, barren, grasslands, croplands, eastern
     forests, coastal wetlands, and water.  For each seasonal land cover region
     there are corresponding sets of attributes of land characteristics
     (vegetation components, seasonal properties, spectral measures, elevation,
     soils, and climate). The complete land characteristics database, available
     on CD-ROM from the EROS Data Center, can be tailored into classification
     legends or parameters required for specific applications. More information
     regarding these data can be found in Loveland et. al. (1991) or by
     contacting Customer Services, USGS, EROS Data Center, Sioux Falls, SD 
     57198.
     
          The Land Cover imagery were produced bi-weekly from the AVHRR
     data and translated to Graphical Interchange Format (GIF) by the
     USGS EROS Data Center. These GIF images can be viewed using any
     standard GIF display software package. However, any additional detailed
     information from the original files (i.e., pixel reflectivity values,
     navigation, etc.) are not retrievable from the GIF image, but can be
     obtained from the digital data available from EROS. 
     
     
     2.1  Detailed Format Description
     
          General information on GIF files, structure and format are provided
     in the References.
     
     2.2  Data Remarks
     
          None. 
     
     3.0  Quality Control Processing
     
          No additional quality control or re-navigation was performed on
     the imagery by the University Corporation for Atmospheric Research/Joint
     Office for Science Support (UCAR/JOSS). 
     
     4.0  References
     
     Kay: Graphics File Formats, 2/E.  ISBN: 0-07-034025-0, McGraw Hill.
     
     Loveland, T.R, J.W. Merchant, D.O. Ohlen, and J.F. Brown, 1991:
          Development of a Land-cover Characteristics Database for the
          Conterminous United States. Photogrammetric Engineering &
          Remote Sensing, Vol 57, No. 11,    November 1991, 
          pp. 1453-1463.
     
     Luse, M: Bitmapped Graphics Programming in C++. ISBN: 0-201-
          63209-8, Addison-Wesley.