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106-584: The Landsat program is the longest-running enterprise for acquisition of satellite imagery of Earth . It is a joint NASA / USGS program. On 23 July 1972, the Earth Resources Technology Satellite was launched. This was eventually renamed to Landsat 1 in 1975. The most recent, Landsat 9 , was launched on 27 September 2021. The instruments on the Landsat satellites have acquired millions of images. The images, archived in

212-474: A license to use their imagery. Thus, the ability to legally make derivative works from commercial satellite imagery is diminished. Privacy concerns have been brought up by some who wish not to have their property shown from above. Google Maps responds to such concerns in their FAQ with the following statement: "We understand your privacy concerns... The images that Google Maps displays are no different from what can be seen by anyone who flies over or drives by

318-792: A continuous image sweep across a swath equivalent to 185 km on the Earth's surface. The MSS's design also emphasized precision; by precisely timing the mirror's movements, it ensured that consecutive images did not overlap. However, by the 1980s, the cost dynamics shifted. Accessing Landsat's imagery became substantially more expensive, making the French SPOT satellite's images a more cost-effective alternative for many users. The rise in Landsat's prices can be attributed to U.S. policy shifts, initiated under President Carter's leadership and finalized during President Reagan's administration. Landsat data provides information that allows scientists to predict

424-642: A degree or two with electronic compasses. Compasses can measure not just azimuth (i. e. degrees to magnetic north), but also altitude (degrees above the horizon), since the magnetic field curves into the Earth at different angles at different latitudes. More exact orientations require gyroscopic-aided orientation , periodically realigned by different methods including navigation from stars or known benchmarks. The quality of remote sensing data consists of its spatial, spectral, radiometric and temporal resolutions. In order to create sensor-based maps, most remote sensing systems expect to extrapolate sensor data in relation to

530-554: A great deal of data handling overhead. These data tend to be generally more useful for many applications. The regular spatial and temporal organization of Level 3 datasets makes it feasible to readily combine data from different sources. While these processing levels are particularly suitable for typical satellite data processing pipelines, other data level vocabularies have been defined and may be appropriate for more heterogeneous workflows. Satellite images provide very useful information to produce statistics on topics closely related to

636-423: A land cover map of Mozambique 's mangrove forest. The main objective was to measure the mangrove cover and above ground biomass 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 -

742-825: A large extent of geography. At the same time, the data is often complex to interpret, and bulky to store. Modern systems tend to store the data digitally, often with lossless compression . The difficulty with this approach is that the data is fragile, the format may be archaic, and the data may be easy to falsify. One of the best systems for archiving data series is as computer-generated machine-readable ultrafiche , usually in typefonts such as OCR-B , or as digitized half-tone images. Ultrafiches survive well in standard libraries, with lifetimes of several centuries. They can be created, copied, filed and retrieved by automated systems. They are about as compact as archival magnetic media, and yet can be read by human beings with minimal, standardized equipment. Generally speaking, remote sensing works on

848-460: 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

954-484: A legend of mapped classes that suits our purpose, taking again the example of wheat. The straightforward approach is counting the number of pixels classified as wheat and multiplying by the area of each pixel. Many authors have noticed that estimator is that it is generally biased because commission and omission errors in a confusion matrix do not compensate each other The main strength of classified satellite images or other indicators computed on satellite images

1060-606: 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. Landsat 8 launched on 11 February 2013. It was launched on an Atlas V 401 from Vandenberg Air Force Base by the Launch Services Program . It will continue to obtain valuable data and imagery to be used in agriculture, education, business, science, and government. The new satellite

1166-472: A reference point including distances between known points on the ground. This depends on the type of sensor used. For example, in conventional photographs, distances are accurate in the center of the image, with the distortion of measurements increasing the farther you get from the center. Another factor is that of the platen against which the film is pressed can cause severe errors when photographs are used to measure ground distances. The step in which this problem

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1272-679: A sample with less accurate, but exhaustive, data for a covariable or proxy that is cheaper to collect. For agricultural statistics, field surveys are usually required, while photo-interpretation may better for land cover classes that can be reliably identified on aerial photographs or high resolution satellite images. Additional uncertainty can appear because of imperfect reference data (ground truth or similar). Some options are: ratio estimator , regression estimator , calibration estimators and small area estimators If we target other variables, such as crop yield or leaf area , we may need different indicators to be computed from images, such as

1378-399: A specific geographic location." Remote sensing This is an accepted version of this page 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 and other planets . Remote sensing

1484-422: 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

1590-422: A wide range of civilian applications, including: mapping, border control, infrastructure planning, agricultural monitoring, environmental monitoring , disaster response, training and simulations, etc. EROS A – a high resolution satellite with 1.9–1.2m resolution panchromatic was launched on December 5, 2000. EROS B – the second generation of Very High Resolution satellites with 70 cm resolution panchromatic,

1696-593: Is a constellation of sub-metre resolution Earth observation satellites that provide imagery, high-definition video and analytics services. Planet acquired the satellites with their purchase of Terra Bella (formerly Skybox Imaging), a Mountain View, California -based company founded in 2009 by Dan Berkenstock, Julian Mann, John Fenwick, and Ching-Yu Hu, from Google in 2017. The SkySat satellites are based on using inexpensive automotive grade electronics and fast commercially available processors, but scaled up to approximately

1802-526: Is a major component of NASA's Science Mission Directorate and the Earth Science Division. The goal of NASA Earth Science is to develop a scientific understanding of the Earth as an integrated system, its response to change, and to better predict variability and trends in climate, weather, and natural hazards. The Meteosat -2 geostationary weather satellite began operationally to supply imagery data on 16 August 1981. Eumetsat has operated

1908-753: Is also the exclusive distributor of data from the high resolution Pleiades satellites with a resolution of 0.50 meter or about 20 inches. The launches occurred in 2011 and 2012, respectively. The company also offers infrastructures for receiving and processing, as well as added value options. Planet Labs operates three satellite imagery constellations, RapidEye , Dove and SkySat . In 2015, Planet acquired BlackBridge , and its constellation of five RapidEye satellites, launched in August 2008. The RapidEye constellation contains identical multispectral sensors which are equally calibrated. Therefore, an image from one satellite will be equivalent to an image from any of

2014-489: Is an imaging instrument onboard Terra, the flagship satellite of NASA's Earth Observing System (EOS) launched in December 1999. ASTER is a cooperative effort between NASA, Japan's Ministry of Economy, Trade and Industry (METI), and Japan Space Systems (J-spacesystems). ASTER data is used to create detailed maps of land surface temperature, reflectance, and elevation. The coordinated system of EOS satellites, including Terra,

2120-420: Is composed of two very-high-resolution (50 centimeters pan & 2.1 meter spectral) optical Earth-imaging satellites . Pléiades-HR 1A and Pléiades-HR 1B provide the coverage of Earth's surface with a repeat cycle of 26 days. Designed as a dual civil/military system, Pléiades will meet the space imagery requirements of European defense as well as civil and commercial needs. Pléiades Neo  [ fr ]

2226-604: Is impossible to directly measure temperatures in the upper atmosphere, it is possible to measure the spectral emissions from a known chemical species (such as carbon dioxide) in that region. The frequency of the emissions may then be related via thermodynamics to the temperature in that region. To facilitate the discussion of data processing in practice, several processing "levels" were first defined in 1986 by NASA as part of its Earth Observing System and steadily adopted since then, both internally at NASA (e. g., ) and elsewhere (e. g., ); these definitions are: A Level 1 data record

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2332-445: Is more expensive per square meter. Satellite imagery can be combined with vector or raster data in a GIS provided that the imagery has been spatially rectified so that it will properly align with other data sets. Satellite imaging of the Earth surface is of sufficient public utility that many countries maintain satellite imaging programs. The United States has led the way in making these data freely available for scientific use. Some of

2438-418: Is providing cheap information on the whole target area or most of it. This information usually has a good correlation with the target variable (ground truth) that is usually expensive to observe in an unbiased and accurate way. Therefore it can be observed on a probabilistic sample selected on an area sampling frame . Traditional survey methodology provides different methods to combine accurate information on

2544-622: Is relatively high, yet revisit time is relatively less frequent. The Landsat program incorporated the Multispectral Scanner (MSS) from its first mission up to its fifth. The MSS gave the United States an advantage in satellite imaging, facilitating the launch of Landsat ahead of the French SPOT satellite. The MSS was unique in its design. Rather than a static camera, it employed a moving mirror, capturing Earth's images in four distinct spectral bands. This capability allowed

2650-450: Is relevant to highlight that probabilistic sampling is not critical for the selection of training pixels for image classification, but it is necessary for accuracy assessment of the classified images and area estimation. Additional care is recommended to ensure that training and validation datasets are not spatially correlated. We suppose now that we have classified images or a land cover map produced by visual photo-interpretation, with

2756-432: Is resolved is called georeferencing and involves computer-aided matching of points in the image (typically 30 or more points per image) which is extrapolated with the use of an established benchmark, "warping" the image to produce accurate spatial data. As of the early 1990s, most satellite images are sold fully georeferenced. In addition, images may need to be radiometrically and atmospherically corrected. Interpretation

2862-472: 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

2968-489: Is that of examined areas or objects that reflect or emit radiation that stand out from surrounding areas. For a summary of major remote sensing satellite systems see the overview table. To coordinate a series of large-scale observations, most sensing systems depend on the following: platform location and the orientation of the sensor. High-end instruments now often use positional information from satellite navigation systems . The rotation and orientation are often provided within

3074-402: Is that of increasingly smaller sensor pods such as those used by law enforcement and the military, in both manned and unmanned platforms. The advantage of this approach is that this requires minimal modification to a given airframe. Later imaging technologies would include infrared, conventional, Doppler and synthetic aperture radar. The development of artificial satellites in the latter half of

3180-490: Is the advanced optical constellation, with four identical 30-cm resolution satellites with fast reactivity. The 3 SPOT satellites in orbit (Spot 5, 6, 7) provide very high resolution images – 1.5 m for Panchromatic channel, 6m for Multi-spectral (R,G,B,NIR). Spot Image also distributes multiresolution data from other optical satellites, in particular from Formosat-2 ( Taiwan ) and Kompsat-2 ( South Korea ) and from radar satellites (TerraSar-X, ERS, Envisat, Radarsat). Spot Image

3286-440: Is the critical process of making sense of the data. The first application was that of aerial photographic collection which used the following process; spatial measurement through the use of a light table in both conventional single or stereographic coverage, added skills such as the use of photogrammetry, the use of photomosaics, repeat coverage, Making use of objects' known dimensions in order to detect modifications. Image Analysis

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3392-560: Is the most fundamental (i. e., highest reversible level) data record that has significant scientific utility, and is the foundation upon which all subsequent data sets are produced. Level 2 is the first level that is directly usable for most scientific applications; its value is much greater than the lower levels. Level 2 data sets tend to be less voluminous than Level 1 data because they have been reduced temporally, spatially, or spectrally. Level 3 data sets are generally smaller than lower level data sets and thus can be dealt with without incurring

3498-418: Is the oldest continuous Earth-observing satellite imaging program. Optical Landsat imagery has been collected at 30 m resolution since the early 1980s. Beginning with Landsat 5 , thermal infrared imagery was also collected (at coarser spatial resolution than the optical data). The Landsat 7 , Landsat 8 , and Landsat 9 satellites are currently in orbit. MODIS has collected near-daily satellite imagery of

3604-424: Is the recently developed automated computer-aided application that is in increasing use. Object-Based Image Analysis (OBIA) is a sub-discipline of GIScience devoted to partitioning remote sensing (RS) imagery into meaningful image-objects, and assessing their characteristics through spatial, spectral and temporal scale. Old data from remote sensing is often valuable because it may provide the only long-term data for

3710-410: Is used in numerous fields, including geophysics , geography , land surveying and most Earth science disciplines (e.g. exploration geophysics , hydrology , ecology , meteorology , oceanography , glaciology , geology ). It also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others. In current usage, the term remote sensing generally refers to

3816-613: The Amazon Basin , glacial features in Arctic and Antarctic regions, and depth sounding of coastal and ocean depths. Military collection during the Cold War made use of stand-off collection of data about dangerous border areas. Remote sensing also replaces costly and slow data collection on the ground, ensuring in the process that areas or objects are not disturbed. Orbital platforms collect and transmit data from different parts of

3922-1023: The EGU or Digital Earth encourage the development of learning modules and learning portals . Examples include: FIS – Remote Sensing in School Lessons , Geospektiv , Ychange , or Spatial Discovery, to promote media and method qualifications as well as independent learning. Remote sensing data are processed and analyzed with computer software, known as a remote sensing application . A large number of proprietary and open source applications exist to process remote sensing data. There are applications of gamma rays to mineral exploration through remote sensing. In 1972 more than two million dollars were spent on remote sensing applications with gamma rays to mineral exploration. Gamma rays are used to search for deposits of uranium. By observing radioactivity from potassium, porphyry copper deposits can be located. A high ratio of uranium to thorium has been found to be related to

4028-556: The European Commission . Forest area and deforestation estimation have also been a frequent target of remote sensing projects, the same as land cover and land use Ground truth or reference data to train and validate image classification require a field survey if we are targetting annual crops or individual forest species, but may be substituted by photointerpretation if we look at wider classes that can be reliably identified on aerial photos or satellite images. It

4134-579: The Magellan spacecraft provided detailed topographic maps of Venus , while instruments aboard SOHO allowed studies to be performed on the Sun and the solar wind , just to name a few examples. Recent developments include, beginning in the 1960s and 1970s, the development of image processing of satellite imagery . The use of the term "remote sensing" began in the early 1960s when Evelyn Pruitt realized that advances in science meant that aerial photography

4240-536: The MetOp spacecraft of EUMETSAT are all operated at altitudes of about 800 km (500 mi). The Proba-1 , Proba-2 and SMOS spacecraft of European Space Agency are observing the Earth from an altitude of about 700 km (430 mi). The Earth observation satellites of UAE, DubaiSat-1 & DubaiSat-2 are also placed in Low Earth orbits (LEO) orbits and providing satellite imagery of various parts of

4346-537: The NDVI , a good proxy to chlorophyll activity. The modern discipline of remote sensing arose with the development of flight. The balloonist G. Tournachon (alias Nadar ) made photographs of Paris from his balloon in 1858. Messenger pigeons, kites, rockets and unmanned balloons were also used for early images. With the exception of balloons, these first, individual images were not particularly useful for map making or for scientific purposes. Systematic aerial photography

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4452-514: The United States and at Landsat receiving stations around the world, are a unique resource for global change research and applications in agriculture , cartography , geology , forestry , regional planning , surveillance and education , and can be viewed through the U.S. Geological Survey (USGS) "EarthExplorer" website. Landsat 7 data has eight spectral bands with spatial resolutions ranging from 15 to 60 m (49 to 197 ft);

4558-615: The electromagnetic spectrum , which in conjunction with larger scale aerial or ground-based sensing and analysis, provides researchers with enough information to monitor trends such as El Niño and other natural long and short term phenomena. Other uses include different areas of the earth sciences such as natural resource management , agricultural fields such as land usage and conservation, greenhouse gas monitoring , oil spill detection and monitoring, and national security and overhead, ground-based and stand-off collection on border areas. The basis for multispectral collection and analysis

4664-451: The sensor used, weather conditions can affect image quality. For example, it is difficult to obtain images for areas of frequent cloud cover such as mountaintops. For such reasons, publicly available satellite image datasets are typically processed for visual or scientific commercial use by third parties. Commercial satellite companies do not place their imagery into the public domain and do not sell their imagery; instead, one must acquire

4770-532: The temporal resolution 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 long and 100 nautical miles wide, or 185 kilometers long and 185 kilometers wide). In 1965, William T. Pecora , the then director of the United States Geological Survey , proposed the idea of a remote sensing satellite program to gather facts about

4876-622: The 20th century allowed remote sensing to progress to a global scale as of the end of the Cold War. Instrumentation aboard various Earth observing and weather satellites such as Landsat , the Nimbus and more recent missions such as RADARSAT and UARS provided global measurements of various data for civil, research, and military purposes. Space probes to other planets have also provided the opportunity to conduct remote sensing studies in extraterrestrial environments, synthetic aperture radar aboard

4982-491: The Earth Observation Satellite Company (EOSAT), a partnership of Hughes Aircraft Company and RCA , 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

5088-478: The German students use the services of Google Earth ; in 2006 alone the software was downloaded 100 million times. But studies have shown that only a fraction of them know more about the data they are working with. There exists a huge knowledge gap between the application and the understanding of satellite images. Remote sensing only plays a tangential role in schools, regardless of the political claims to strengthen

5194-507: 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 in general,

5300-453: The MSS to record variations in sunlight reflected from the Earth. Notably, Landsat 3's MSS was further advanced, with an added capability to detect heat radiation. One of the prominent features of the MSS was its consistent imaging. Each captured frame represented an area on the Earth's surface approximately 83 meters in length and 68 meters in width. Additionally, the system was designed to ensure

5406-580: The Meteosats since 1987. The Himawari satellite series represents a significant leap forward in meteorological observation and environmental monitoring. With their advanced imaging technology and frequent data updates, Himawari-8 and Himawari-9 have become indispensable tools for weather forecasting, disaster management, and climate research, benefiting not only Japan but the entire Asia-Pacific region. Several satellites are built and maintained by private companies, as follows. GeoEye's GeoEye-1 satellite

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5512-584: The USGS convinced the Secretary of the Interior , Stewart Udall , 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

5618-422: The commercial high-resolution satellite market, EROS is the smallest very high resolution satellite; it is very agile and thus enables very high performances. The satellites are deployed in a circular Sun-synchronous near polar orbit at an altitude of 510 km (± 40 km). EROS satellites imagery applications are primarily for intelligence, homeland security and national development purposes but also employed in

5724-743: The data. Landsat 1 through 5 carried the Landsat Multispectral Scanner (MSS). Landsat 4 and 5 carried both the MSS and Thematic Mapper (TM) instruments. Landsat 7 uses the Enhanced Thematic Mapper Plus (ETM+) scanner. Landsat 8 uses two instruments, the Operational Land Imager (OLI) for optical bands and the Thermal Infrared Sensor (TIRS) for thermal bands. The band designations, bandpasses, and pixel sizes for

5830-495: The discovery of the Earth's Van Allen radiation belts . The TIROS-1 spacecraft, launched on April 1, 1960, as part of NASA's Television Infrared Observation Satellite (TIROS) program, sent back the first television footage of weather patterns to be taken from space. In 2008, more than 150 Earth observation satellites were in orbit, recording data with both passive and active sensors and acquiring more than 10 terabits of data daily. By 2021, that total had grown to over 950, with

5936-418: 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

6042-565: The earth in 36 spectral bands since 2000. MODIS is on board the NASA Terra and Aqua satellites. The ESA is currently developing the Sentinel constellation of satellites. Currently, 7 missions are planned, each for a different application. Sentinel-1 (SAR imaging), Sentinel-2 (decameter optical imaging for land surfaces), and Sentinel-3 (hectometer optical and thermal imaging for land and water) have already been launched. The ASTER

6148-486: The economic reform of 1970, and the change in development rate and construction rate was accelerated in these time periods. 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

6254-406: 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 in 1986. Landsat imagery gives

6360-642: The farmer who plants his fields in a remote corner of the country knows its value." The development of remote sensing technology reached a climax during the Cold War with the use of modified combat aircraft such as the P-51 , P-38 , RB-66 and the F-4C , or specifically designed collection platforms such as the U2/TR-1 , SR-71 , A-5 and the OV-1 series both in overhead and stand-off collection. A more recent development

6466-417: The fields of media and methods apart from the mere visual interpretation of satellite images. Many teachers have great interest in the subject "remote sensing", being motivated to integrate this topic into teaching, provided that the curriculum is considered. In many cases, this encouragement fails because of confusing information. In order to integrate remote sensing in a sustainable manner organizations like

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6572-581: The first commercial satellite (IKONOS) collecting very high resolution imagery was launched. Remote Sensing has a growing relevance in the modern information society. It represents a key technology as part of the aerospace industry and bears increasing economic relevance – new sensors e.g. TerraSAR-X and RapidEye are developed constantly and the demand for skilled labour is increasing steadily. Furthermore, remote sensing exceedingly influences everyday life, ranging from weather forecasts to reports on climate change or natural disasters . As an example, 80% of

6678-646: The future, there may also be more collaboration between Landsat satellites and other satellites with similar spatial and spectral resolution, such as the ESA 's Sentinel-2 constellation. Landsat Next is planned to launch in late 2030/early 2031 and will measure 26 spectral bands; current Landsat's 8 and 9 measure 11 each. Satellite imagery The first images from space were taken on sub-orbital flights . The US-launched V-2 flight on October 24, 1946, took one image every 1.5 seconds. With an apogee of 65 miles (105 km), these photos were from five times higher than

6784-436: The importance of Landsat imagery and satellite images in general. The Yellowstone fires of 1988 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

6890-518: The instrument used and the altitude of the satellite's orbit. For example, the Landsat archive offers repeated imagery at 30 meter resolution for the planet, but most of it has not been processed from the raw data. Landsat 7 has an average return period of 16 days. For many smaller areas, images with resolution as fine as 41 cm can be available. Satellite imagery is sometimes supplemented with aerial photography , which has higher resolution, but

6996-461: The largest number of satellites operated by US-based company Planet Labs . Most Earth observation satellites carry instruments that should be operated at a relatively low altitude. Most orbit at altitudes above 500 to 600 kilometers (310 to 370 mi). Lower orbits have significant air-drag , which makes frequent orbit reboost maneuvers necessary. The Earth observation satellites ERS-1, ERS-2 and Envisat of European Space Agency as well as

7102-465: The launch of the first artificial satellite, Sputnik 1 , by the Soviet Union on October 4, 1957. Sputnik 1 sent back radio signals, which scientists used to study the ionosphere . The United States Army Ballistic Missile Agency launched the first American satellite, Explorer 1 , for NASA's Jet Propulsion Laboratory on January 31, 1958. The information sent back from its radiation detector led to

7208-683: 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

7314-500: The mangrove area is spread across 16° of latitude but it the biomass volume of it was affected more strongly by geographic conditions. The shrinking of the Aral Sea 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

7420-637: The more popular programs are listed below, recently followed by the European Union 's Sentinel constellation. The CORONA program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency (CIA) Directorate of Science & Technology with substantial assistance from the U.S. Air Force . The type of imagery is wet film panoramic and it used two cameras (AFT&FWD) for capturing stereographic imagery. Landsat

7526-503: The name was changed to Landsat. In 1979, President of the United States Jimmy Carter 's Presidential Directive 54 transferred Landsat operations from NASA to National Oceanic and Atmospheric Administration (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

7632-478: 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

7738-595: The new satellite-generated imagery was to find high yield fishery areas. Through the Landsat Menhaden and Thread Investigation, some satellite data of the eastern portion of the Mississippi sound and another area off the coast of the Louisiana coast data was run through classification algorithms to rate the areas as high and low probability fishing zones, these algorithms yielded a classification that

7844-520: The other four, allowing for a large amount of imagery to be collected (4 million km per day), and daily revisit to an area. Each travel on the same orbital plane at 630 km, and deliver images in 5 meter pixel size. RapidEye satellite imagery is especially suited for agricultural, environmental, cartographic and disaster management applications. The company not only offers their imagery, but consults their customers to create services and solutions based on analysis of this imagery. The RapidEye constellation

7950-522: The other hand, emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR and LiDAR are examples of active remote sensing where the time delay between emission and return is measured, establishing the location, speed and direction of an object. Remote sensing makes it possible to collect data of dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as

8056-852: The presence of hydrothermal copper deposits. Radiation patterns have also been known to occur above oil and gas fields, but some of these patterns were thought to be due to surface soils instead of oil and gas. 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 , meteorology , cartography and others. The most common type are Earth imaging satellites, that take satellite images , analogous to aerial photographs ; some EO satellites may perform remote sensing without forming pictures, such as in GNSS radio occultation . The first occurrence of satellite remote sensing can be dated to

8162-620: The previous record, the 13.7 miles (22 km) by the Explorer II balloon mission in 1935. The first satellite (orbital) photographs of Earth were made on August 14, 1959, by the U.S. Explorer 6 . The first satellite photographs of the Moon might have been made on October 6, 1959, by the Soviet satellite Luna 3 , on a mission to photograph the far side of the Moon. The Blue Marble photograph

8268-412: The principle of the inverse problem : while the object or phenomenon of interest (the state ) may not be directly measured, there exists some other variable that can be detected and measured (the observation ) which may be related to the object of interest through a calculation. The common analogy given to describe this is trying to determine the type of animal from its footprints. For example, while it

8374-508: 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: 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. In 1975, one potential application for

8480-447: The public. Several other countries have satellite imaging programs, and a collaborative European effort launched the ERS and Envisat satellites carrying various sensors. There are also private companies that provide commercial satellite imagery. In the early 21st century satellite imagery became widely available when affordable, easy to use software with access to satellite imagery databases

8586-468: 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

8692-500: The reflection of sunlight is detected by the sensor). Remote sensing can be divided into two types of methods: Passive remote sensing and Active remote sensing. Passive sensors gather radiation that is emitted or reflected by the object or surrounding areas. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography , infrared , charge-coupled devices , and radiometers . Active collection, on

8798-405: The same orbit, providing 0.5m panchromatic resolution and 2m multispectral resolution on a swath of 12 km. Because the total area of the land on Earth is so large and because resolution is relatively high, satellite databases are huge and image processing (creating useful images from the raw data) is time-consuming. Preprocessing, such as image destriping , is often required. Depending on

8904-524: The satellite applications mentioned above, these data can serve as powerful educational tools, advance scientific research and promote a deeper understanding of our environment. This shows that satellite imagery provides rich information and can promote global development. There are five types of resolution when discussing satellite imagery in remote sensing: spatial, spectral, temporal, radiometric and geometric. Campbell (2002) defines these as follows: The resolution of satellite images varies depending on

9010-430: 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 from Santa Barbara Research Center initiated, designed, and fabricated the first three Multispectral Scanners (MSS) in 1969. The first MSS prototype, designed by Virginia Norwood ,

9116-424: The satellite to distinguish between objects on the ground that are at least 46 cm apart. Similarly Maxar's QuickBird satellite provides 0.6 meter resolution (at nadir ) panchromatic images. Maxar's WorldView-3 satellite provides high resolution commercial satellite imagery with 0.31 m spatial resolution. WVIII also carries a short wave infrared sensor and an atmospheric sensor. Pléiades constellation

9222-407: The size of a minifridge . The satellites are approximately 80 centimetres (31 in) long, compared to approximately 30 centimetres (12 in) for a 3U CubeSat, and weigh 100 kilograms (220 lb). Earth Resource Observation Satellites , better known as "EROS" satellites, are lightweight, low earth orbiting, high-resolution satellites designed for fast maneuvering between imaging targets. In

9328-459: 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. The serial nature of Landsat missions and

9434-423: The support for teaching on the subject. A lot of the computer software explicitly developed for school lessons has not yet been implemented due to its complexity. Thereby, the subject is either not at all integrated into the curriculum or does not pass the step of an interpretation of analogue images. In fact, the subject of remote sensing requires a consolidation of physics and mathematics as well as competences in

9540-639: The territory, such as agriculture, forestry or land cover in general. The first large project to apply Landsata 1 images for statistics was LACIE (Large Area Crop Inventory Experiment), run by NASA, NOAA and the USDA in 1974–77. Many other application projects on crop area estimation have followed, including the Italian AGRIT project and the MARS project of the Joint Research Centre (JRC) of

9646-422: The use of satellite - or aircraft-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and oceans , based on propagated signals (e.g. electromagnetic radiation ). It may be split into "active" remote sensing (when a signal is emitted by a satellite or aircraft to the object and its reflection is detected by the sensor) and "passive" remote sensing (when

9752-431: 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

9858-540: Was assembled in Arizona by Orbital Sciences Corporation . Landsat 9 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 Congressional Research Service . United States Senate appropriators advised NASA to plan for

9964-537: Was completed within nine months, in the fall of 1970. It was tested by scanning Half Dome at Yosemite National Park . For this design work Norwood was 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

10070-591: Was developed for military surveillance and reconnaissance purposes beginning in World War I . After WWI, remote sensing technology was quickly adapted to civilian applications. This is demonstrated by the first line of a 1941 textbook titled "Aerophotography and Aerosurverying," which stated the following: "There is no longer any need to preach for aerial photography-not in the United States- for so widespread has become its use and so great its value that even

10176-463: Was due to run out (NOAA had not requested any funding, and U.S. Congress 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 , Vice President Dan Quayle , 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

10282-589: Was launched on April 25, 2006. EROS C2 – the third generation of Very High Resolution satellites with 30 cm. resolution panchromatic, was launched in 2021. EROS C3 – the third generation of Very High Resolution satellites with 30 cm. resolution panchromatic and multispectral, was launched in 2023. GaoJing-1 / SuperView-1 (01, 02, 03, 04) is a commercial constellation of Chinese remote sensing satellites controlled by China Siwei Surveying and Mapping Technology Co. Ltd. The four satellites operate from an altitude of 530 km and are phased 90° from each other on

10388-533: Was launched on September 6, 2008. The GeoEye-1 satellite has high resolution imaging system and is able to collect images with a ground resolution of 0.41 meters (16 inches) in panchromatic or black and white mode. It collects multispectral or color imagery at 1.65-meter resolution or about 64 inches. Maxar's WorldView-2 satellite provides high resolution commercial satellite imagery with 0.46 m spatial resolution (panchromatic only). The 0.46 meters resolution of WorldView-2's panchromatic images allows

10494-559: Was no longer an adequate term to describe the data streams being generated by new technologies. With assistance from her fellow staff member at the Office of Naval Research, Walter Bailey, she coined the term "remote sensing". Several research groups in Silicon Valley including NASA Ames Research Center , GTE , and ESL Inc. developed Fourier transform techniques leading to the first notable enhancement of imagery data. In 1999

10600-542: Was offered by several companies and organizations. Satellite images have numerous applications in a variety of fields. Less mainstream uses include anomaly hunting, a criticized investigation technique involving the search of satellite images for unexplained phenomena. The spectrum of satellite images is diverse, including visible light, near-infrared light, infrared light and radar, and many others. This wide range of light frequencies can provide researchers with large volumes of useful and rich information. In addition to

10706-504: 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 through remote sensing with Landsat satellite imagery. The program was initially called the Earth Resources Technology Satellites Program, which was used from 1966 to 1975. In 1975,

10812-664: 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 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,

10918-497: Was proven with in situ measurements – to be over 80% accurate and found that water color, as seen from space, and turbidity significantly correlate with the distribution of menhaden – 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 , turbidity , and possibly fish distribution. An ecological study used 16 ortho-rectified Landsat images to generate

11024-546: 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

11130-489: Was retired by Planet in April 2020. Planet's Dove satellites are CubeSats that weigh 4 kilograms (8.8 lb), 10 by 10 by 30 centimetres (3.9 in × 3.9 in × 11.8 in) in length, width and height, orbit at a height of about 400 kilometres (250 mi) and provide imagery with a resolution of 3–5 metres (9.8–16.4 ft) and are used for environmental, humanitarian, and business applications. SkySat

11236-526: Was taken from space in 1972, and has become very popular in the media and among the public. Also in 1972 the United States started the Landsat program , the largest program for acquisition of imagery of Earth from space. In 1977, the first real time satellite imagery was acquired by the United States' KH-11 satellite system. The most recent Landsat satellite, Landsat 9 , was launched on 27 September 2021. All satellite images produced by NASA are published by NASA Earth Observatory and are freely available to

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