Landsat GeoCover at the Global Land Cover Facility
GeoCover Orthorectification Description
In support of the U.S. Government's Mission to Planet Earth (now Earth Science Enterprise (ESE)), EarthSat produced a
unified global database from Landsat imagery acquired between 1972 and 2000. The objective of the project was to
produce a single common product with the highest possible geometric accuracy, available to earth scientists around the
world at minimum cost. Over 24,000 Landsat scenes were acquired and processed. For each scene EarthSat provided to
- An orthorectified nearest neighbor-resampled all-band dataset suitable for scientific analysis
- An orthorectified seamless color-balanced mosaic using three bands suitable for GIS and public display.
Mosaics were provided uncompressed (GeoTIFF) and compressed (MrSID).
- As of December 2003, the year 2000 (Landsat 7), the 1990 (Landsat TM), and the 1975 (Landsat MSS)
datasets are complete.
The project involved the invention of specialized software called Massive Block Triangulation (U.S. Patent
No. 6,125,329), which permits the block bundle adjustment of 1,200 Landsat scenes simultaneously with sparse
control. Without the ability to use sparse control, a project of this magnitude would have been economically
unfeasible. Positional accuracy is just over 1 pixel and has exceeded specifications.
EarthSat staff traveled to 10 foreign ground-receiving stations to locate the very best images in
existence. Examination of 300,000 meta-records and quicklooks required the development of very efficient screening
The availability of the GeoCover dataset has revolutionized the development of global natural resource and global
change analysis. In addition to NASA, other agencies, including USDA, State Dept, USAID, UNEP, UN/FAO, World Bank,
numerous NGO's and thousands of individual users use GeoCover Ortho data. GeoCover Ortho was crucial as the source data
for the GeoCover LC global Landcover dataset acquired by NIMA to support SRTM and global GIS databases.