The Landsat Program is a joint effort of the USGS and NASA to gather Earth resource data using a series of land observing satellites. Whereas NASA’s role is the development and launch of Earth observing instruments and spacecrafts, the USGS is responsible for flight operations, maintenance, and management of all ground data reception, processing, archiving, product generation, and distribution. A primary objective of the Landsat Program is to ensure a collection of consistently calibrated Earth imagery.
Recently, the Landsat project has embarked upon an effort to retain a copy of all of these images at the Landsat archive at USGS EROS. This effort, called the Global Archive Consolidation, includes over a dozen stations that have downlinked over 5 million images over the last 40 years. Data that are the oldest, called Multispectral Scanner (MSS), are at rather high risk of loss, since the data are old by digital standards and many technical changes have occurred in the intervening years. The longest running sensor, the Thematic Mapper (TM), comprises the bulk of the international archives, collecting data since 1982. The most advanced sensor, the Enhanced Thematic Mapper Plus (ETM+), has been managed by the USGS to acquire the entire globe at least four times per year, but additional data can be found in international archives.
In FY 2011, the Landsat project ingested over 500,000 new images into the USGS Landsat archive. The project had significant success ingesting data from Canada, as well as starting on the Indonesian and Puerto Rican archives. The new copies of international images include higher quality scenes over parts of Canada, and one of the only clear images of Singapore in the entire last two decades.