Landsat 5 GeoCover, Orthorectified TM
These 1990's vintage orthorectified Landsat 5 TM scenes, made available through NASA's Science Data Purchase (SDP) Program, will be used as base-line geocoded images for each site. The images are stated to be "orthorectified to an accuracy of 50 meters using control points from other government sources." See (http://www.crsp.ssc.nasa.gov/datab/ESAT.HTM).
As part of the NASA SDP program, EarthSat will create at least one orthorectified image for each path and row in the global Landsat World Reference System.
All seven bands of the Landsat 5 TM data are provided, as well as a metadata file and browse imagery. The resampling was done using a nearest neighbor kernal.
Current, GeoCover scenes are available free on-line at the University of Maryland's "Global Land Cover Facility"