Revision history for Fact Sheet 2015–3081 Landsat—Earth Observation Satellites By U.S. Geological Survey ----------------------------------------------------- Posted online November 25, 2015 ----------------------------------------------------- Revised and reposted August 22, 2016, version 1.1 Page 1, 3rd paragraph, last sentence, date was changed from 2023 to 2020. Page 1, figure 1 was updated with new information. Page 4, email address changed to custserv@usgs.gov ----------------------------------------------------- Revised and reposted April 2, 2020, version 1.2 Figure 1 was replaced with an updated graphic. On p. 1, the sentence "Landsat 8, launched in 2013, continues the mission, and Landsat 9 is tentatively planned to launch in 2020 (fig. 1)." was changed to "Landsat 8, launched in 2013, continues the mission and Landsat 9 is scheduled to be launched in March 2021 (fig. 1)." In the "For more information" section, "Landsat Remote Sensing Program" was changed to "Land Remote Sensing Program." Hyperlinks were updated. ----------------------------------------------------- Revised and reposted August 1, 2022, version 1.3 In the first paragraph, the text was changed from "The data are useful to a number of applications including forestry, agriculture, geology, regional planning, and education." to "The data are useful for a number of applications including forestry, agriculture, geology, regional planning, and education." In the beginning of the third paragraph, the text was changed from "U.S. successes" to "U.S. success." At the end of the third paragraph, the text was changed from "Landsat 6 failed to achieve orbit in 1993; however, Landsat 7 successfully launched in 1999 and continues to provide global data. Landsat 8, launched in 2013, continues the mission, and Landsat 9 is scheduled to be launch in mid-2021 (fig. 1)." to "Landsat 6 failed to achieve orbit in 1993; however, Landsat 7 successfully launched in 1999. In April 2022, Landsat 7 lowered its orbit by 8 kilometers but will continue to provide data until September 2022. Landsat 8, launched in 2013, and Landsat 9, launched in 2021, continue the mission of acquiring global data (fig. 1)." On page 2, the first paragraph was changed from "The Landsat 7 and Landsat 8 satellites both orbit the Earth at an altitude of 705 kilometers (438 miles) in a 185-kilometer (115-mile) swath, moving from north to south over the sunlit side of the Earth in a sun synchronous orbit. Each satellite makes a complete orbit every 99 minutes, completes about 14 full orbits each day, and crosses every point on Earth once every 16 days. Although each satellite has a 16-day full-Earth-coverage cycle, their orbits are offset to allow 8-day repeat coverage of any Landsat scene area on the globe. Between the two satellites, more than 1,000 scenes are added to the USGS archive each day. Landsats 4 and 5 followed the same orbit as Landsats 7 and 8, whereas Landsats 1, 2, and 3 orbited at an altitude of 920 kilometers (572 miles), circling the Earth every 103 minutes, yielding repeat coverage every 18 days." to "The Landsat 8 and Landsat 9 satellites orbit the Earth at an altitude of 705 kilometers (438 miles) in a 185-kilometer (115-mile) swath, moving from north to south over the sunlit side of the Earth in a sun synchronous orbit. Each satellite makes a complete orbit every 99 minutes, completes about 14 full orbits each day, and crosses every point on Earth once every 16 days. Although each satellite has a 16-day full-Earth-coverage cycle, their orbits are offset to allow 8-day repeat coverage of any Landsat scene area on the globe. Between the two satellites, more than 1,500 scenes are added to the USGS archive each day. Landsats 4, 5, and 7 followed the same orbit as Landsats 8 and 9, whereas Landsats 1, 2, and 3 orbited at an altitude of 920 kilometers (572 miles), circling the Earth every 103 minutes, yielding repeat coverage every 18 days." On page 2, the second paragraph was changed from "The Landsat Long Term Acquisition Plans (LTAPs) identify Earth imaging priorities that most effectively utilize both Landsat 8 and Landsat 7 data acquisitions. Information about the LTAPs is provided on the Landsat Missions Web site (https://www.usgs.gov/land-resources/nli/landsat)." to "The Landsat Long Term Acquisition Plans (LTAPs) identify Earth imaging priorities that most effectively utilize both Landsat 8 and Landsat 9 data acquisitions. Information about the LTAPs is provided on the Landsat Missions website (https://www.usgs.gov/landsat-missions)." On page 2, in the fourth paragraph, a sentence was changed from "Efforts to recover the SLC were unsuccessful, and without an operating SLC, 22 percent of the image data are missing, which results in data gaps forming in alternating wedges that increase in width from the center to the edge of the image. Landsat 7 still acquires geometrically and radiometrically accurate data worldwide, and methods have been established that allow users to fill the data gaps." to "Efforts to recover the SLC were unsuccessful, and without an operating SLC, 22 percent of the image data are missing, resulting in data gaps forming in alternating wedges that increase in width from the center to the edge of the image. Landsat 7 still acquires geometrically and radiometrically accurate data worldwide, and methods were established that allow users to fill the data gaps." On pages 2 to 3, a paragraph was changed from "Landsat 8, launched as the Landsat Data Continuity Mission on February 11, 2013, contains the push-broom Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). OLI collects data with a spatial resolution of 30 meters in the visible, near-IR, and SWIR wavelength regions, and a 15-meter panchromatic band, which provides data compatible with products from previous missions. OLI also contains a deep blue band for coastal-aerosol studies and a band for cirrus cloud detection (table 1). The TIRS contains two thermal bands, which were designed to allow the use of split-window surface temperature retrieval algorithms; however, because of larger calibration uncertainty associated with band 11, it is recommended that users refrain from using band 11 data." to "Landsat 8, launched on February 11, 2013, and Landsat 9, launched on September 27, 2021, each have two sensors: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). OLI collects data with a spatial resolution of 30 meters in the visible, near-IR, and SWIR wavelength regions, and a 15-meter panchromatic band, which provides data compatible with products from previous missions. OLI also has a deep blue band for coastal-aerosol studies and a band for cirrus cloud detection (table 1). TIRS has two thermal bands, which were designed to allow the use of split-window surface temperature retrieval algorithms. Because of larger calibration uncertainty associated with Landsat 8's band 11, it is recommended that users refrain from using band 11 data." In table 2, the heading was changed from "L8" to "L8-9" On page 3, in the first full paragraph, a sentence was changed from "A Quality Assessment (QA) band is also included in Landsat 8 data products." to "A Quality Assessment (QA) band is also included in Landsat 8 and 9 data products." On page 3, in the "Applications of Landsat Data" section, the text was changed from "Specific environmental monitoring activities such as deforestation research, volcanic flow studies, and understanding the effects of natural disasters all benefit from the availability of Landsat data. In recent years, Landsat data have also been used to track oil spills and to monitor mine waste pollution. Table 2 lists Landsat bands and describes the use of each band to help users determine the best bands to use in data analysis." to "Specific environmental monitoring activities such as deforestation research, understanding pyroclastic flows, and understanding the effects of natural disasters all benefit from the availability of Landsat data. In recent years, Landsat data also are used to track oil spills and to monitor mine waste pollution. Table 2 lists Landsat bands and describes the use of each band to help users determine the best band combinations to use in data analysis." On page 3, in the first paragraph of the "Landsat Data Products and Processing" section, the text was changed from "The USGS delivers high quality systematic, geometric, radiometric, and terrain corrected data to users worldwide, and since December 2008, without any cost to users. Millions of Landsat scenes have been downloaded since moving to the open archive model." to "The USGS delivers high quality systematic, geometric, radiometric, and terrain corrected data to users worldwide. Nearly 150 million Landsat images have been downloaded since the USGS adopted the free and open Landsat policy in December 2008." In the second paragraph of the "Landsat Data Products and Processing" section, "products" was removed from "Landsat Level-1 data products." On page 4, in the first paragraph, two sentences were changed from "Data are delivered in Georeferenced Tagged Image File Format (GeoTIFF) in compressed files for faster downloads." to "Data are delivered in Cloud Optimized Georeferenced Tagged Image File Format (GeoTIFF) (COG) in compressed files for faster downloads." and from "Full resolution “natural” color composite Joint Photographic Expert Group (.jpg) files of Landsat images (named LandsatLook Images) are also available to download for easy use in presentations and visual interpretation." to "Full resolution “natural” color composite Joint Photographic Expert Group (.jpg) files of Landsat images (named Full Resolution Browse Images) are also available to download for easy use in presentations and visual interpretation." On page 4, in the first full paragraph, text was changed from "Recognizing the need for new climate information products to meet national and international requirements in accordance with the Global Climate Observing System (GCOS), USGS scientists developed higher-level science data products (also known as Level-2). Higher-level data are processed to support time series of observational data with sufficient length, consistency, and continuity to record effects of climate change. Atmospherically corrected Landsat surface reflectance data are the first Level-2 products produced by the USGS. Surface-reflectance-based spectral indices are also available. Landsat surface reflectance and other higher-level data are considered provisional (fig. 3)." to "Recognizing the need for new climate information products to meet national and international requirements in accordance with the Global Climate Observing System (GCOS), USGS scientists developed higher level science products to support time series of observational data with sufficient length, consistency, and continuity to record effects of climate change. Visit https://www.usgs.gov/landsat-missions/landsat-science-products for more information on the various science products (fig. 3)." In the first paragraph of the "Obtaining Landsat Data Products" section, text was changed from "Landsat Level-1 data products held in the USGS archives are available for download at no charge and with no restrictions from EarthExplorer (https://earthexplorer.usgs.gov), GloVis (https://glovis.usgs.gov), or the LandsatLook Viewer (https://landsatlook.usgs.gov). Bulk downloading capabilities are available by accessing the EarthExplorer Help menu." to "Landsat Level-1 data and science products held in the USGS archives are available for download at no charge and with no restrictions from EarthExplorer (https://earthexplorer.usgs.gov), GloVis (https://glovis.usgs.gov), the LandsatLook Viewer https://landsatlook.usgs.gov), or through the commercial cloud. Bulk downloading capabilities are available by accessing the EarthExplorer Help menu." In the second paragraph of the "Obtaining Landsat Data Products" section, text was changed from "Requests for Landsat Level-2 science data products can be placed by using EarthExplorer (surface reflectance data only) or by accessing the EROS Science Processing Architecture (ESPA) on-demand interface (https://espa.cr.usgs.gov) to submit a list of scenes for processing. Because the Level-2 data products require the use of Level-1 data, the higher-level data are not immediately downloadable but become available as soon as the creation of the Level-2 products is complete." to "For more information about how to search and download Landsat data and science products, please visit https://www.usgs.gov/landsat-missions/landsat-data-access." In the "Landsat Science Teams" section, the hyperlink was updated from https://usgs.gov/landsat to https://www.usgs.gov/landsat-missions/landsat-science-teams. In the colophon, the Twitter handle (@USGSLandsat) was changed to the hyperlink (https://www.twitter.com/USGSLandsat). The Facebook hyperlink was changed from "https://www.facebook.com/NASA.Landsat" to "https://www.facebook.com/USGSLandsatProgram." An Instagram hyperlink was added. A USGS hyperlink was changed from "https://www.usgs.gov/land-resources/national-landimaging- program" to "https://www.usgs.gov/programs/national-land-imaging-program." ----------------------------------------------------- Revised and reposted August 24, 2022, version 1.4 On p. 1, in the second paragraph, a sentence was revised from "Landsat 6 failed to achieve orbit in 1993; however, Landsat 7 successfully launched in 1999." to "Landsat 6 failed to achieve orbit in 1993; Landsat 7 successfully launched in 1999." On p. 2, in the "Sensors and Band Designations" section, a value was changed from 79 meters to 80 meters. A sentence was revised from "Return Beam Vidicon (RBV) instruments on Landsats 1, 2, and 3 acquired data at 40-meter resolution, and were recorded to 70-millimeter black and white film." to "Return Beam Vidicon (RBV) instruments on Landsats 1, 2, and 3 acquired data that were recorded to 70-millimeter black and white film." In table 1, a value was revised from 79 meters to 80 meters.