Landsat: Half a Century of Watching Earth From Space

The Landsat missions since 1972. USGS.

The program

Since 1972, Landsat satellites have continuously imaged Earth's land surface, building an unmatched record of natural and human-caused change used in forestry, agriculture, geology, regional planning and education.

• NASA develops the instruments and spacecraft, launches them and checks their performance.
• The USGS then owns and runs the satellites and handles ground reception, archiving, product generation and distribution.

The missions

Orbits

• Landsat 8 and 9 fly at 705 km (438 mi) in a sun-synchronous orbit, imaging a 185-km (115-mi) swath from north to south over the sunlit side. Each orbits every 99 minutes (about 14 a day) and passes over every point every 16 days; offset from each other, together they revisit every 8 days, adding more than 1,500 scenes a day.
• Landsats 4, 5 and 7 flew the same orbit; Landsats 1–3 flew at 920 km (572 mi), orbiting every 103 minutes and repeating every 18 days.
• Long Term Acquisition Plans set imaging priorities.

Sensors

• Landsat 7's glitch: on May 31, 2003, its Scan Line Corrector failed. Without it, 22 percent of each image is missing in wedge-shaped gaps widening toward the edges. The data are still accurate, and methods exist to fill the gaps.
• OLI adds a deep blue band for coastal and aerosol studies and a cirrus cloud band. TIRS has two thermal bands for surface-temperature retrieval — though users should avoid Landsat 8's band 11, which has larger calibration uncertainty.
• A Quality Assessment band flags pixels affected by instrument artifacts or clouds.

Uses

Global change research, agriculture, forestry, geology, land-cover mapping, resource management, water and coastal studies — plus deforestation, volcanic flows, natural disasters and, more recently, oil spills and mine waste. A consistent, deep archive and free data make long time series possible.

Dubai's expanding artificial archipelagos: (A) October 1998, Landsat 5; (B) May 2003, Landsat 7; (C) May 2008, Landsat 5; (D) May 2015. USGS.

Data products

• Nearly 150 million Landsat images have been downloaded since the USGS made the archive free and open in December 2008.
• Level-1 data come corrected geometrically, radiometrically and for terrain, north-up in UTM (Polar Stereographic for Antarctica) on the WGS 1984 datum, as Cloud Optimized GeoTIFFs; full-resolution natural-color JPEG browse images are also available.
• Higher-level science products, such as surface reflectance, support climate records under the Global Climate Observing System.

Landsat 8, May 11, 2014, Peruvian rain forest: (A) standard Level-1 data and (B) surface reflectance. USGS.

Getting the data

Download Level-1 data and science products free, without restrictions, from EarthExplorer, GloVis, the LandsatLook Viewer or the commercial cloud; bulk download is available through EarthExplorer. Landsat Science Teams, co-chaired by the USGS and NASA, advise on acquisitions, products and applications. More: Landsat Missions and data access.

Sources

Based on "Landsat—Earth Observation Satellites," U.S. Geological Survey fact sheet (updated 2022); a work of the United States government in the public domain. The timeline and images are taken from the fact sheet's PDF.