On April 21, 2008, the USGS announced plans to provide all archived Landsat scenes at no charge to all users. View the original Technical Announcement - .pdf (66.8 KB).
All scenes are processed using the parameters shown below. Scenes that have a quality score of 9, and have 40 or less percent cloud cover will be automatically processed. Any archived scene, regardless of cloud cover, will be processed upon request and made available for download.
All Landsat Standard data products are processed using the LPGS* system with the following parameters applied:Level 1T (terrain corrected) product**
* Beginning September 15, 2010, the Level 1 Product Generation System (LPGS) became the primary processing system used for all Landsat standard data products. A small number of Landsat TM scenes are still processed using the National Land Archive Production System (NLAPS). Differences between these two processing systems are detailed at http://landsat.usgs.gov/products_IP_LPGSvsNLAPS.php.
** While most data will be processed as Level 1T (precision and terrain corrected), certain scenes do not have ground-control or elevation data necessary for precision or terrain correction, respectively. In these cases, the best level of correction will be applied (Level 1G-systematic or Level 1Gt-systematic terrain). Specific L1T scenes are available for most of the globe under the Global Land Surveys (GLS) of 1975, 1990, 2000, and 2005. These datasets can be found on GloVis or EarthExplorer.