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The Landsat program is the longest-running enterprise for acquisition of
satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...
of
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
. It is a joint
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
/
USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...
program. On 23 July 1972, the
Earth Resources Technology Satellite Landsat 1 (LS-1), formerly named ERTS-A and ERTS-1, was the first satellite of the United States' Landsat program. It was a modified version of the Nimbus 4 Meteorology, meteorological satellite and was launched on July 23, 1972, by a Delta 01 ...
was launched. This was eventually renamed to Landsat 1 in 1975. The most recent,
Landsat 9 Landsat 9 is an Earth observation satellite launched on 27 September 2021 from Space Launch Complex-3E at Vandenberg Space Force Base on an Atlas V 401 launch vehicle. NASA is in charge of building, launching, and testing the satellite, while ...
, was launched on 27 September 2021. The instruments on the Landsat satellites have acquired millions of images. The images, archived in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
and at Landsat receiving stations around the world, are a unique resource for global change research and applications in
agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
,
cartography Cartography (; from grc, χάρτης , "papyrus, sheet of paper, map"; and , "write") is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an im ...
,
geology Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
,
forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. Th ...
,
regional planning Regional planning deals with the efficient placement of land-use activities, infrastructure, and settlement growth across a larger area of land than an individual city or town. Regional planning is related to urban planning as it relates land ...
,
surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. This can include observation from a distance by means of electronic equipment, such as c ...
and
education Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty. Va ...
, and can be viewed through the U.S. Geological Survey (USGS) "EarthExplorer" website.
Landsat 7 Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat program is managed and ...
data has eight
spectral bands Spectral bands are parts of the electromagnetic spectrum of specific wavelengths, which can be filtered by a standard filter. In nuclear physics, spectral bands are referred to the emission of polyatomic systems, including condensed materials, larg ...
with spatial resolutions ranging from ; the
temporal resolution Temporal resolution (TR) refers to the discrete resolution of a measurement with respect to time. Physics Often there is a trade-off between the temporal resolution of a measurement and its spatial resolution, due to Heisenberg's uncertainty p ...
is 16 days. Landsat images are usually divided into scenes for easy downloading. Each Landsat scene is about 115 miles long and 115 miles wide (or 100
nautical miles A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today t ...
long and 100 nautical miles wide, or 185 kilometers long and 185 kilometers wide).


History

In 1965, William T. Pecora, the then director of the
United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
, proposed the idea of a remote sensing satellite program to gather facts about the natural resources of our planet. Pecora stated that the program was “conceived in 1966 largely as a direct result of the demonstrated utility of the Mercury and Gemini orbital photography to Earth resource studies.” While weather satellites had been monitoring Earth’s atmosphere since 1960 and were largely considered useful, there was no appreciation of terrain data from space until the mid-1960s. So, when Landsat 1 was proposed, it met with intense opposition from the Bureau of Budget and those who argued high-altitude aircraft would be the fiscally responsible choice for Earth remote sensing. Concurrently, the Department of Defense feared that a civilian program such as Landsat would compromise the secrecy of their reconnaissance missions. Additionally, there were also geopolitical concerns about photographing foreign countries without permission. In 1965, NASA began methodical investigations of Earth remote sensing using instruments mounted on planes. In 1966, the USGS convinced the
Secretary of the Interior Secretary of the Interior may refer to: * Secretary of the Interior (Mexico) * Interior Secretary of Pakistan * Secretary of the Interior and Local Government (Philippines) * United States Secretary of the Interior See also

*Interior ministry ...
,
Stewart Udall Stewart Lee Udall (January 31, 1920 – March 20, 2010) was an American politician and later, a federal government official. After serving three terms as a congressman from Arizona, he served as Secretary of the Interior from 1961 to 1969, unde ...
, to announce that the Department of the Interior (DOI) was going to proceed with its own Earth-observing satellite program. This savvy political stunt coerced NASA to expedite the building of Landsat. But budgetary constraints and sensor disagreements between application agencies (notably the Department of Agriculture and DOI) again stymied the satellite construction process. Finally, by 1970 NASA had a green light to build a satellite. Remarkably, within only two years, Landsat 1 was launched, heralding a new age of remote sensing of land from space. The
Hughes Aircraft Company The Hughes Aircraft Company was a major American aerospace and defense contractor founded on February 14, 1934 by Howard Hughes in Glendale, California, as a division of Hughes Tool Company. The company was known for producing, among other produ ...
from Santa Barbara Research Center initiated, designed, and fabricated the first three
Multispectral Scanner The Multispectral Scanner (MSS) is one of the Earth's observing sensors introduced in the Landsat program. A Multispectral Scanner was placed aboard each of the first five Landsat satellites. : "The Multispectral Scanner System", NASA Official: Dar ...
s (MSS) in 1969. The first MSS prototype, designed by Virginia Norwood, was completed within nine months, in the fall of 1970. It was tested by scanning
Half Dome Half Dome is a granite dome at the eastern end of Yosemite Valley in Yosemite National Park, California. It is a well-known rock formation in the park, named for its distinct shape. One side is a sheer face while the other three sides are smooth ...
at
Yosemite National Park Yosemite National Park ( ) is an American national park in California, surrounded on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers an ar ...
. For this design work Norwood is called "The Mother of Landsat." Working at NASA's Goddard Space Flight Center, Valerie L. Thomas managed the development of early Landsat image processing software systems and became the resident expert on the Computer Compatible Tapes, or CCTs, that were used to store early Landsat imagery. Thomas was one of the image processing specialists who facilitated the ambitious Large Area Crop Inventory Experiment, known as LACIE — a project that showed for the first time that global crop monitoring could be done with Landsat satellite imagery. The program was initially called the Earth Resources Technology Satellites Program, which was used from 1966 to 1975. In 1975, the name was changed to Landsat. In 1979,
President of the United States The president of the United States (POTUS) is the head of state and head of government of the United States of America. The president directs the executive branch of the federal government and is the commander-in-chief of the United Stat ...
Jimmy Carter James Earl Carter Jr. (born October 1, 1924) is an American politician who served as the 39th president of the United States from 1977 to 1981. A member of the Democratic Party (United States), Democratic Party, he previously served as th ...
's Presidential Directive 54 transferred Landsat operations from
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...
to
National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...
(NOAA), recommended development of a long term operational system with four additional satellites beyond Landsat 3, and recommended transition to private sector operation of Landsat. This occurred in 1985 when the Earth Observation Satellite Company (EOSAT), a partnership of
Hughes Aircraft Company The Hughes Aircraft Company was a major American aerospace and defense contractor founded on February 14, 1934 by Howard Hughes in Glendale, California, as a division of Hughes Tool Company. The company was known for producing, among other produ ...
and
RCA The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
, was selected by NOAA to operate the Landsat system with a ten-year contract. EOSAT operated Landsat 4 and Landsat 5, had exclusive rights to market Landsat data, and was to build Landsats 6 and 7. In 1989, this transition had not been fully completed when NOAA's funding for the Landsat program was due to run out (NOAA had not requested any funding, and
U.S. Congress The United States Congress is the legislature of the federal government of the United States. It is Bicameralism, bicameral, composed of a lower body, the United States House of Representatives, House of Representatives, and an upper body, ...
had appropriated only six months of funding for the fiscal year) and NOAA directed that Landsat 4 and Landsat 5 be shut down. The head of the newly formed
National Space Council The National Space Council is a body within the Executive Office of the President of the United States created in 1989 during the George H. W. Bush administration, disbanded in 1993, and reestablished in June 2017 by the Donald Trump administrati ...
, Vice President
Dan Quayle James Danforth Quayle (; born February 4, 1947) is an American politician who served as the 44th vice president of the United States from 1989 to 1993 under President George H. W. Bush. A member of the Republican Party (United States), Republic ...
, noted the situation and arranged emergency funding that allowed the program to continue with the data archives intact. Again in 1990 and 1991, Congress provided only half of the year's funding to NOAA, requesting that agencies that used Landsat data provide the funding for the other six months of the upcoming year. In 1992, various efforts were made to procure funding for follow on Landsats and continued operations, but by the end of the year EOSAT ceased processing Landsat data. Landsat 6 was finally launched on 5 October 1993, but was lost in a launch failure. Processing of Landsat 4 and 5 data was resumed by EOSAT in 1994. NASA finally launched Landsat 7 on 15 April 1999. The value of the Landsat program was recognized by Congress in October 1992 when it passed the Land Remote Sensing Policy Act (Public Law 102-555) authorizing the procurement of Landsat 7 and assuring the continued availability of Landsat digital data and images, at the lowest possible cost, to traditional and new users of the data.


Satellite chronology

;Timeline ImageSize = width:750 height:auto barincrement:21 PlotArea = left:70 bottom:30 top:10 right:10 TimeAxis = orientation:horizontal format:yyyy Colors = id:canvas value:gray(0.97) id:grid1 value:gray(0.8) id:grid2 value:gray(0.6) BackgroundColors = canvas:canvas DateFormat = mm/dd/yyyy Period = from:01/01/1972 till:01/01/2022 AlignBars = justify ScaleMajor = increment:2 start:1973 unit:year grid:grid1 ScaleMinor = increment:1 start:1974 unit:year BarData = bar:Landsat1 text:"Landsat 1" bar:Landsat2 text:"Landsat 2" bar:Landsat3 text:"Landsat 3" bar:Landsat4 text:"Landsat 4" bar:Landsat5 text:"Landsat 5" bar:Landsat6 text:"Landsat 6" bar:Landsat7 text:"Landsat 7" bar:Landsat8 text:"Landsat 8" bar:Landsat9 text:"Landsat 9" PlotData = align:left anchor:from fontsize:M width:13 shift:(4,-6) textcolor:black bar:Landsat1 from:07/23/1972 till:01/06/1978 color:blue bar:Landsat2 from:01/22/1975 till:02/25/1982 color:blue bar:Landsat3 from:03/05/1978 till:03/31/1983 color:blue bar:Landsat4 from:07/16/1982 till:12/14/1993 color:orange bar:Landsat5 from:03/01/1984 till:06/05/2013 color:orange bar:Landsat6 from:10/05/1993 till:10/05/1993 color:black bar:Landsat7 from:04/15/1999 till:05/31/2003 color:red bar:Landsat7 from:05/31/2003 till:end color:coral bar:Landsat8 from:02/11/2013 till:end color:green bar:Landsat9 from:09/27/2021 till:end color:green


Spatial and spectral resolution

Landsat 1 through 5 carried the Landsat
Multispectral Scanner The Multispectral Scanner (MSS) is one of the Earth's observing sensors introduced in the Landsat program. A Multispectral Scanner was placed aboard each of the first five Landsat satellites. : "The Multispectral Scanner System", NASA Official: Dar ...
(MSS). Landsat 4 and 5 carried both the MSS and
Thematic Mapper A Thematic Mapper (TM) is one of the Earth observing sensors introduced in the Landsat program. The first was placed aboard Landsat 4 (decommissioned in 2001), and another was operational aboard Landsat 5 up to 2012. /sup> TM sensors feature seven ...
(TM) instruments. Landsat 7 uses the
Enhanced Thematic Mapper Plus ''Enhanced'' is a 2019 Canadian-Japanese action film produced, written and directed by James Mark. The film premiered at the 2019 Toronto After Dark Film Festival. Plot A sinister government organization hunts down mutants, and one of such is a y ...
(ETM+) scanner. Landsat 8 uses two instruments, the
Operational Land Imager The Operational Land Imager (OLI) is a remote sensing instrument aboard Landsat 8, built by Ball Aerospace & Technologies. Landsat 8 is the successor to Landsat 7 and was launched on February 11, 2013. OLI is a push broom scanner that uses a fo ...
(OLI) for optical bands and the Thermal Infrared Sensor (TIRS) for thermal bands. The band designations, bandpasses, and pixel sizes for the Landsat instruments are: * Original MSS pixel size was 79 x 57 meters; production systems now resample the data to 60 meters. * TM Band 6 was acquired at 120-meter resolution, but products are resampled to 30-meter pixels. * ETM+ Band 6 is acquired at 60-meter resolution, but products are resampled to 30-meter pixels. * TIRS bands are acquired at 100 meter resolution, but are resampled to 30 meter in delivered data product. An advantage of Landsat imagery, and
remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth ...
in general, is that it provides data at a synoptic global level that is impossible to replicate with in situ measurements. However, there are tradeoffs between the local detail of the measurements (radiometric resolution, number of spectral bands) and the spatial scale of the area being measured. Landsat imagery is coarse in spatial resolution compared to using other remote sensing methods, such as imagery from airplanes. Compared to other satellites, Landsat’s spatial resolution is relatively high, yet revisit time is relatively less frequent.


MultiSpectral Scanner (MSS) sensor design

The
Multispectral Scanner The Multispectral Scanner (MSS) is one of the Earth's observing sensors introduced in the Landsat program. A Multispectral Scanner was placed aboard each of the first five Landsat satellites. : "The Multispectral Scanner System", NASA Official: Dar ...
(MSS) onboard Landsat missions 1 through 5 was originally built with an engineering solution that allowed the United States to develop Landsat-1 at least five years ahead of the French
SPOT Spot or SPOT may refer to: Places * Spot, North Carolina, a community in the United States * The Spot, New South Wales, a locality in Sydney, Australia * South Pole Traverse, sometimes called the South Pole Overland Traverse People * Spot (prod ...
. The original MSS had a fused silica dinner-plate mirror epoxy bonded to three
invar Invar, also known generically as FeNi36 (64FeNi in the US), is a nickel–iron alloy notable for its uniquely low coefficient of thermal expansion (CTE or α). The name ''Invar'' comes from the word ''invariable'', referring to its relative lac ...
tangent bars mounted to base of a
nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
/
gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
brazed Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, with the filler metal having a lower melting point than the adjoining metal. Brazing differs from we ...
Invar frame in a
Serrurier truss A Serrurier truss is used in telescope tube assembly construction. The design was created in 1935 by engineer Mark U. Serrurier when he was working on the Mount Palomar Hale telescope.Encyclopedia of Astronomy and Physics, "Reflecting Telescopes" ...
that was arranged with four "Hobbs-Links" (conceived by Dr. Gregg Hobbs), crossing at mid-truss. This construct ensured the
secondary mirror A secondary mirror (or secondary) is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirro ...
would simply oscillate about the primary optic axis to maintain focus despite vibration inherent from the
beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...
scan mirror. In contrast,
SPOT Spot or SPOT may refer to: Places * Spot, North Carolina, a community in the United States * The Spot, New South Wales, a locality in Sydney, Australia * South Pole Traverse, sometimes called the South Pole Overland Traverse People * Spot (prod ...
first used
charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...
(CCD) arrays to stare without need for a scanner. However, LANDSAT data prices climbed from US$250 per computer compatible data tape and US$10 for black-and-white print to US$4,400 for data tape and US$2,700 for black-and-white print by 1984, making SPOT data a much more affordable option for satellite imaging data. This was a direct result of the commercialization efforts begun under the Carter administration, though finally completed under the
Reagan administration Ronald Reagan's tenure as the 40th president of the United States began with his first inauguration on January 20, 1981, and ended on January 20, 1989. Reagan, a Republican from California, took office following a landslide victory over D ...
. The MSS
Focal Plane Array A staring array, also known as staring-plane array or focal-plane array (FPA), is an image sensor consisting of an array (typically rectangular) of light-sensing pixels at the focal plane of a lens. FPAs are used most commonly for imaging purpo ...
consisted of 24 square optical fibers extruded down to square fiber tips in a 4 x 6 array to be scanned across the
Nimbus Nimbus, from the Latin for "dark cloud", is an outdated term for the type of cloud now classified as the nimbostratus cloud. Nimbus also may refer to: Arts and entertainment * Halo (religious iconography), also known as ''Nimbus'', a ring of ligh ...
spacecraft path in a ±6° scan as the satellite was in a 90 minute
polar orbit A polar orbit is one in which a satellite passes above or nearly above both poles of the body being orbited (usually a planet such as the Earth, but possibly another body such as the Moon or Sun) on each revolution. It has an inclination of about ...
. The
fiber optic An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to ...
bundle was embedded in a fiber optic plate to be terminated at a relay optic device that transmitted fiber end signal on into six photodiodes and 18 photomultiplier tubes that were arrayed across a thick
aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...
tool plate, with sensor weight balanced vs the telescope on opposite side. This main plate was assembled on a frame, then attached to the
silver Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
-loaded
magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...
housing with helicoil fasteners. Key to the success of the multi spectral scanner was the scan monitor mounted on the underbelly of the magnesium housing. It consisted of a diode light source and a sensor mounted at the ends of four flat mirrors that were tilted so that it took 14 bounces for a beam to reflect the length of the three mirrors from source to sender. The beam struck the beryllium scan mirror eight times as it reflected eight times off the flat mirrors. The beam only sensed three positions, being both ends of scan and the mid scan, but by interpolating between these positions that was all that was required to determine where the multi spectral scanner was pointed. Using the scan monitor information, the scanning data could be calibrated to display correctly on a map.


Uses of Landsat imagery

Landsat data provides information that allows scientists to predict the distribution of species, as well as detecting both naturally occurring and human-generated changes over a greater scale than traditional data from field work. The different spectral bands used on satellites in the Landsat program provide many applications, ranging from ecology to geopolitical matters. Land cover determination is a common use of Landsat imagery around the world. Landsat imagery provides one of the longest uninterrupted time series available from any single remote sensing program, spanning from 1972 to present. Looking to the future, the successful launch of Landsat-9 in 2021 shows that this time series will be continued forward. In 2015, the Landsat Advisory Group of the National Geospatial Advisory Committee reported that the top 16 applications of Landsat imagery produced savings of approximately 350 million to over 436 million dollars each year for federal and state governments, NGO’s, and the private sector. That estimate did not include further savings from other uses beyond the top sixteen categories. The top 16 categories for Landsat imagery use, listed in order of estimated annual savings for users, are: # U.S. Department of Agriculture risk management # U.S. Government mapping # Agricultural water use monitoring # Global security monitoring # Support for fire management # Detection of forest fragmentation # Detection of forest change # World agriculture supply and demand estimates # Vineyard management and water conservation # Flood mitigation mapping # Agricultural commodities mapping # Waterfowl habitat mapping and monitoring # Coastal change analysis # Forest health monitoring # National Geospatial-Intelligence Agency global shoreline mapping # Wildfire risk assessment Further uses of Landsat imagery include, but are not limited to: fisheries, forestry, shrinking inland water bodies, fire damage, glacier retreat, urban development, and discovery of new species. A few specific examples are explained below.


Natural resources management


Fisheries

In 1975, one potential application for the new satellite-generated imagery was to find high yield
fishery Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
areas. Through the Landsat Menhaden and Thread Investigation, some satellite data of the eastern portion of the
Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...
sound and another area off the coast of the
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
coast data was run through classification
algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
s to rate the areas as high and low probability fishing zones, these algorithms yielded a classification that was proven with
in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...
measurements – to be over 80% accurate and found that water color, as seen from space, and turbidity significantly correlate with the distribution of
menhaden Menhaden, also known as mossbunker and bunker and "the most important fish in the sea", are forage fish of the genera ''Brevoortia'' and ''Ethmidium'', two genera of marine fish in the family Clupeidae. ''Menhaden'' is a blend of ''poghaden'' ...
– while surface temperature and salinity do not appear to be significant factors. Water color – measured with the multispectral scanners four spectral bands, was used to infer
Chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...
,
turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can ...
, and possibly fish distribution.


Forestry

An ecological study used 16 ortho-rectified Landsat images to generate a land cover map of
Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...
's
mangrove A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...
forest. The main objective was to measure the mangrove cover and above ground
biomass Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
on this zone that until now could only be estimated, the cover was found with 93% accuracy to be 2909 square kilometers (27% lower than previous estimates). Additionally, the study helped confirm that geological setting has a greater influence on biomass distribution than latitude alone - the mangrove area is spread across 16° of latitude but it the biomass volume of it was affected more strongly by geographic conditions.


Climate change and environmental disasters


Shrinking of the Aral Sea

The shrinking of the
Aral Sea The Aral Sea ( ; kk, Арал теңізі, Aral teñızı; uz, Орол денгизи, Orol dengizi; kaa, Арал теңизи, Aral teńizi; russian: Аральское море, Aral'skoye more) was an endorheic basin, endorheic lake lyi ...
has been described as "One of the planet's worst environmental disasters". Landsat imagery has been used as a record to quantify the amount of water loss and the changes to the shoreline. Satellite visual images have a greater impact on people than just words, and this shows the importance of Landsat imagery and satellite images in general.


Fires in Yellowstone National Park

The
Yellowstone fires of 1988 The Yellowstone fires of 1988 collectively formed the largest wildfire in the recorded history of Yellowstone National Park in the United States. Starting as many smaller individual fires, the flames quickly spread out of control due to drought ...
were the worst in the recorded history of the national park. They lasted from 14 June to 11 September 1988, when rain and snow helped halt the spread of the fires. The area affected by the fire was estimated to be 3,213 square kilometers – 36% of the park. Landsat imagery was used for the area estimation, and it also helped determine the reasons why the fire spread so quickly. Historic drought and a significant number of lightning strikes were some of the factors that created conditions for the massive fire, but anthropogenic actions amplified the disaster. On images generated previous to the fire, there is an evident difference between lands that display preservation practices and the lands that display clear cut activities for timber production. These two type of lands reacted differently to the stress of fires, and it is believed that that was an important factor on the behavior of the wildfire. Landsat imagery, and satellite imagery in general, have contributed to understanding fire science; fire danger, wildfire behavior and the effects of wildfire on certain areas. It has helped understanding of how different features and vegetation fuel fires, change temperature, and affect the spreading speed.


Glacier retreat

The serial nature of Landsat missions and the fact that is the longest-running satellite program gives it a unique perspective to generate information of Earth. Glacier retreat in a big scale can be traced back to previous Landsat missions, and this information can be used to generate climate change knowledge. The Columbia glacier retreat for example, can be observed in false-composite images since
Landsat 4 Landsat 4 is the fourth satellite of the Landsat program. It was launched on July 16, 1982, with the primary goal of providing a global archive of satellite imagery. Although the Landsat Program is managed by NASA, data from Landsat 4 was coll ...
in 1986.


Urban development

Landsat imagery gives a time-lapse like series of images of development. Human development specifically, can be measured by the size a city grows over time. Further than just population estimates and energy consumption, Landsat imagery gives an insight of the type of urban development, and study aspects of social and political change through visible change. In Beijing for example, a series of ring roads started to develop in 1980s following the economic reform of 1970, and the change in development rate and construction rate was accelerated in these time periods.


Ecology


Discovery of new species

In 2005, Landsat imagery assisted in the discovery of new species. Conservation scientist Julian Bayliss wanted to find areas that could potentially become conservation forests using Landsat generated satellite images. Bayliss saw a patch in Mozambique that until then had no detailed information. On a reconnaissance trip, he found great diversity of wildlife as well as three new species of butterflies and a new snake species. Following his discovery, he continued to study this forest and was able to map and determine the forest extent.


Recent and future Landsat satellites

Landsat 8 Landsat 8 is an American Earth observation satellite launched on 11 February 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. Originally called the Landsat Data Continuity Mission (LDCM), it is a ...
launched on 11 February 2013. It was launched on an
Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture be ...
401 from
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by the
Launch Services Program The NASA Launch Services Program (LSP) is responsible for procurement of launch services for NASA uncrewed missions and oversight of launch integration and launch preparation activity, providing added quality and mission assurance to meet program ...
. It will continue to obtain valuable data and imagery to be used in agriculture, education, business, science, and government. The new satellite was assembled in
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Orbital Sciences Corporation Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...
.
Landsat 9 Landsat 9 is an Earth observation satellite launched on 27 September 2021 from Space Launch Complex-3E at Vandenberg Space Force Base on an Atlas V 401 launch vehicle. NASA is in charge of building, launching, and testing the satellite, while ...
launched on September 27, 2021. During FY2014 financial planning "appropriators chided NASA for unrealistic expectations that a Landsat 9 would cost US$1 billion, and capped spending at US$650 million" according to a report by the
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.
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appropriators advised NASA to plan for a launch no later than 2020. In April 2015, NASA and the USGS announced that work on Landsat 9 had commenced, with funding allocated for the satellite in the president's FY2016 budget, for a planned launch in 2023. Funding for the development of a low-cost thermal infrared (TIR) free-flying satellite for launch in 2019 was also proposed, to ensure data continuity by flying in formation with Landsat 8. In the future, there may also be more collaboration between Landsat satellites and other satellites with similar spatial and spectral resolution, such as the
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Sentinel-2 Sentinel-2 is an Earth observation mission from the Copernicus Programme that systematically acquires optical imagery at high spatial resolution (10 m to 60 m) over land and coastal waters. The mission is currently a constellation with two satel ...
constellation. Landsat NeXt is planned to be launched in 2029. NeXt will measure 25 spectral bands; current Landsat's 8 and 9 can measure only 11.


Gallery

Overview of the Thermal Infrared Sensor.ogv, Overview of the Thermal Infrared Sensor (TIRS), one of the instruments on Landsat 8. Timelapse of TIRS for LDCM.ogv, A timelapse of the Thermal Infrared Sensor (TIRS) instrument for Landsat 8 being cleaned, bagged, and packed to ship to Orbital Sciences Corp, where TIRS will be integrated with the spacecraft. Florida Everglades Landsat 5 Band Remix (high res).ogv, Animation showing how different LDCM bands can be combined to obtain different information over the
Florida Everglades The Everglades is a natural region of tropical climate, tropical wetlands in the southern portion of the U.S. state of Florida, comprising the southern half of a large drainage basin within the Neotropical realm. The system begins near Orland ...
. Landsat 8 LDCM Liftoff 5min.png, Screenshot capture from NASA TV showing the Atlas V during the launch of Landsat 8.


See also

*
Earth observation satellite An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, me ...
*
Geographic information system A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, sof ...
*
Orthophoto An orthophoto, orthophotograph, orthoimage or orthoimagery is an aerial photograph or satellite imagery geometrically corrected ("orthorectified") such that the scale is uniform: the photo or image follows a given map projection. Unlike an ...
, corrected for uniform scale like a map *
Remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth ...


References


External links


Landsat USGS homepage

Landsat NASA homepage
* * Landsat imagery fro
GLOVIS
an
Global Land Cover Facility
* Landsat mosaic imagery from th
WELD
project. {{Authority control Articles containing video clips Earth observation satellites of the United States National Oceanic and Atmospheric Administration NASA programs United States Geological Survey Satellite imagery 1966 introductions