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97-458: There are two primary methods for capturing information on land cover: field survey, and analysis of remotely sensed imagery . Land change models can be built from these types of data to assess changes in land cover over time. One of the major land cover issues (as with all natural resource inventories) is that every survey defines similarly named categories in different ways. For instance, there are many definitions of " forest "—sometimes within

194-484: A complex processing procedure. Agfa's similarly structured Agfacolor Neu was introduced in 1936. Unlike Kodachrome, the color couplers in Agfacolor Neu were incorporated into the emulsion layers during manufacture, which greatly simplified the processing. Currently, available color films still employ a multi-layer emulsion and the same principles, most closely resembling Agfa's product. Instant color film , used in

291-451: A degree of image post-processing that is comparatively difficult in film-based photography and permits different communicative potentials and applications. Digital photography dominates the 21st century. More than 99% of photographs taken around the world are through digital cameras, increasingly through smartphones. A large variety of photographic techniques and media are used in the process of capturing images for photography. These include

388-690: 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

485-554: 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

582-825: 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

679-484: 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

776-546: A monochrome image from one shot in color. Color photography was explored beginning in the 1840s. Early experiments in color required extremely long exposures (hours or days for camera images) and could not "fix" the photograph to prevent the color from quickly fading when exposed to white light. The first permanent color photograph was taken in 1861 using the three-color-separation principle first published by Scottish physicist James Clerk Maxwell in 1855. The foundation of virtually all practical color processes, Maxwell's idea

873-472: 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

970-679: 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

1067-441: A special camera which yielded a unique finished color print only a minute or two after the exposure, was introduced by Polaroid in 1963. Color photography may form images as positive transparencies, which can be used in a slide projector , or as color negatives intended for use in creating positive color enlargements on specially coated paper. The latter is now the most common form of film (non-digital) color photography owing to

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1164-406: A type of camera obscura in his experiments. The Arab physicist Ibn al-Haytham (Alhazen) (965–1040) also invented a camera obscura as well as the first true pinhole camera . The invention of the camera has been traced back to the work of Ibn al-Haytham. While the effects of a single light passing through a pinhole had been described earlier, Ibn al-Haytham gave the first correct analysis of

1261-401: Is a box with a small hole in one side, which allows specific light rays to enter, projecting an inverted image onto a viewing screen or paper. The birth of photography was then concerned with inventing means to capture and keep the image produced by the camera obscura. Albertus Magnus (1193–1280) discovered silver nitrate , and Georg Fabricius (1516–1571) discovered silver chloride , and

1358-542: Is an accepted version of this page Photography is the art , application, and practice of creating images by recording light , either electronically by means of an image sensor , or chemically by means of a light-sensitive material such as photographic film . It is employed in many fields of science, manufacturing (e.g., photolithography ), and business, as well as its more direct uses for art, film and video production , recreational purposes, hobby, and mass communication . A person who captures or takes photographs

1455-421: Is an invisible latent image , which is later chemically "developed" into a visible image, either negative or positive , depending on the purpose of the photographic material and the method of processing . A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print , either by using an enlarger or by contact printing . The word "photography"

1552-461: Is applied especially to acquiring information about Earth and other planets . Remote sensing 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,

1649-443: Is called a photographer . Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure . With an electronic image sensor, this produces an electrical charge at each pixel , which is electronically processed and stored in a digital image file for subsequent display or processing. The result with photographic emulsion

1746-562: Is detected by the sensor) and "passive" remote sensing (when 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

1843-419: Is distinct from " land use ", despite the two terms often being used interchangeably. Land use is a description of how people utilize the land and of socio-economic activity . Urban and agricultural land uses are two of the most commonly known land use classes. At any one point or place, there may be multiple and alternate land uses, the specification of which may have a political dimension. The origins of

1940-604: 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

2037-399: Is kept dark while the object to be photographed is in another room where it is properly illuminated. This was common for reproduction photography of flat copy when large film negatives were used (see Process camera ). As soon as photographic materials became "fast" (sensitive) enough for taking candid or surreptitious pictures, small "detective" cameras were made, some actually disguised as

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2134-418: 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

2231-450: 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

2328-432: 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

2425-399: Is stored electronically, but can be reproduced on a paper. The camera (or ' camera obscura ') is a dark room or chamber from which, as far as possible, all light is excluded except the light that forms the image. It was discovered and used in the 16th century by painters. The subject being photographed, however, must be illuminated. Cameras can range from small to very large, a whole room that

2522-489: 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

2619-402: 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

2716-440: 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

2813-531: Is the earliest known occurrence of the word in public print. It was signed "J.M.", believed to have been Berlin astronomer Johann von Maedler . The astronomer John Herschel is also credited with coining the word, independent of Talbot, in 1839. The inventors Nicéphore Niépce , Talbot, and Louis Daguerre seem not to have known or used the word "photography", but referred to their processes as "Heliography" (Niépce), "Photogenic Drawing"/"Talbotype"/"Calotype" (Talbot), and "Daguerreotype" (Daguerre). Photography

2910-560: 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

3007-424: 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

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3104-486: Is the result of combining several technical discoveries, relating to seeing an image and capturing the image. The discovery of the camera obscura ("dark chamber" in Latin ) that provides an image of a scene dates back to ancient China . Greek mathematicians Aristotle and Euclid independently described a camera obscura in the 5th and 4th centuries BCE. In the 6th century CE, Byzantine mathematician Anthemius of Tralles used

3201-598: 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

3298-1013: 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

3395-547: 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

3492-632: The Frauenkirche and other buildings in Munich, then taking another picture of the negative to get a positive , the actual black and white reproduction of a view on the object. The pictures produced were round with a diameter of 4 cm, the method was later named the "Steinheil method". In France, Hippolyte Bayard invented his own process for producing direct positive paper prints and claimed to have invented photography earlier than Daguerre or Talbot. British chemist John Herschel made many contributions to

3589-571: 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

3686-527: 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

3783-533: 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

3880-615: 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

3977-473: The "land cover/land use" couplet and the implications of their confusion are discussed in Fisher et al. (2005). Following table is Land Cover statistics by Food and Agriculture Organization (FAO) with 14 classes. Land cover change detection using remote sensing and geospatial data provides baseline information for assessing the climate change impacts on habitats and biodiversity, as well as natural resources, in

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4074-613: 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

4171-403: The 21st century. Hurter and Driffield began pioneering work on the light sensitivity of photographic emulsions in 1876. Their work enabled the first quantitative measure of film speed to be devised. The first flexible photographic roll film was marketed by George Eastman , founder of Kodak in 1885, but this original "film" was actually a coating on a paper base. As part of the processing,

4268-483: The Earth. To get global coverage with a low orbit, a polar orbit is used. A low orbit will have an orbital period of roughly 100 minutes and the Earth will rotate around its polar axis about 25° between successive orbits. The ground track moves towards the west 25° each orbit, allowing a different section of the globe to be scanned with each orbit. Most are in Sun-synchronous orbits . Photography This

4365-682: The French inventor Nicéphore Niépce , but it was destroyed in a later attempt to make prints from it. Niépce was successful again in 1825. In 1826 he made the View from the Window at Le Gras , the earliest surviving photograph from nature (i.e., of the image of a real-world scene, as formed in a camera obscura by a lens ). Because Niépce's camera photographs required an extremely long exposure (at least eight hours and probably several days), he sought to greatly improve his bitumen process or replace it with one that

4462-474: 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

4559-505: The Nobel Prize in Physics in 1908. Glass plates were the medium for most original camera photography from the late 1850s until the general introduction of flexible plastic films during the 1890s. Although the convenience of the film greatly popularized amateur photography, early films were somewhat more expensive and of markedly lower optical quality than their glass plate equivalents, and until

4656-403: The advantages of being considerably tougher, slightly more transparent, and cheaper. The changeover was not completed for X-ray films until 1933, and although safety film was always used for 16 mm and 8 mm home movies, nitrate film remained standard for theatrical 35 mm motion pictures until it was finally discontinued in 1951. Films remained the dominant form of photography until

4753-458: The camera and lens to "expose" the light recording material to the required amount of light to form a " latent image " (on plate or film) or RAW file (in digital cameras) which, after appropriate processing, is converted to a usable image. Digital cameras use an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) or complementary metal–oxide–semiconductor (CMOS) technology. The resulting digital image

4850-405: The camera obscura, including the first geometrical and quantitative descriptions of the phenomenon, and was the first to use a screen in a dark room so that an image from one side of a hole in the surface could be projected onto a screen on the other side. He also first understood the relationship between the focal point and the pinhole, and performed early experiments with afterimages , laying

4947-416: The camera, but in 1840 he created the calotype process, which used the chemical development of a latent image to greatly reduce the exposure needed and compete with the daguerreotype. In both its original and calotype forms, Talbot's process, unlike Daguerre's, created a translucent negative which could be used to print multiple positive copies; this is the basis of most modern chemical photography up to

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5044-418: The camera; dualphotography; full-spectrum, ultraviolet and infrared media; light field photography; and other imaging techniques. The camera is the image-forming device, and a photographic plate , photographic film or a silicon electronic image sensor is the capture medium. The respective recording medium can be the plate or film itself, or a digital magnetic or electronic memory. Photographers control

5141-495: 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

5238-687: The earliest surviving photographic self-portrait. In Brazil, Hercules Florence had apparently started working out a silver-salt-based paper process in 1832, later naming it Photographie . Meanwhile, a British inventor, William Fox Talbot , had succeeded in making crude but reasonably light-fast silver images on paper as early as 1834 but had kept his work secret. After reading about Daguerre's invention in January 1839, Talbot published his hitherto secret method and set about improving on it. At first, like other pre-daguerreotype processes, Talbot's paper-based photography typically required hours-long exposures in

5335-590: The early 21st century when advances in digital photography drew consumers to digital formats. Although modern photography is dominated by digital users, film continues to be used by enthusiasts and professional photographers. The distinctive "look" of film based photographs compared to digital images is likely due to a combination of factors, including (1) differences in spectral and tonal sensitivity (S-shaped density-to-exposure (H&D curve) with film vs. linear response curve for digital CCD sensors), (2) resolution, and (3) continuity of tone. Originally, all photography

5432-487: The experiments toward the light-sensitive silver halides , which Niépce had abandoned many years earlier because of his inability to make the images he captured with them light-fast and permanent. Daguerre's efforts culminated in what would later be named the daguerreotype process. The essential elements—a silver-plated surface sensitized by iodine vapor, developed by mercury vapor, and "fixed" with hot saturated salt water—were in place in 1837. The required exposure time

5529-625: 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

5626-417: 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

5723-587: The first glass negative in late 1839. In the March 1851 issue of The Chemist , Frederick Scott Archer published his wet plate collodion process . It became the most widely used photographic medium until the gelatin dry plate, introduced in the 1870s, eventually replaced it. There are three subsets to the collodion process; the Ambrotype (a positive image on glass), the Ferrotype or Tintype (a positive image on metal) and

5820-581: 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

5917-547: The first modern "integral tripack" (or "monopack") color film, was introduced by Kodak in 1935. It captured the three color components in a multi-layer emulsion . One layer was sensitized to record the red-dominated part of the spectrum , another layer recorded only the green part and a third recorded only the blue. Without special film processing , the result would simply be three superimposed black-and-white images, but complementary cyan, magenta, and yellow dye images were created in those layers by adding color couplers during

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6014-445: The foundations for the invention of photography in the 19th century. Leonardo da Vinci mentions natural camerae obscurae that are formed by dark caves on the edge of a sunlit valley. A hole in the cave wall will act as a pinhole camera and project a laterally reversed, upside down image on a piece of paper. Renaissance painters used the camera obscura which, in fact, gives the optical rendering in color that dominates Western Art. It

6111-440: The glass negative, which was used to make positive prints on albumen or salted paper. Many advances in photographic glass plates and printing were made during the rest of the 19th century. In 1891, Gabriel Lippmann introduced a process for making natural-color photographs based on the optical phenomenon of the interference of light waves. His scientifically elegant and important but ultimately impractical invention earned him

6208-428: The image-bearing layer was stripped from the paper and transferred to a hardened gelatin support. The first transparent plastic roll film followed in 1889. It was made from highly flammable nitrocellulose known as nitrate film. Although cellulose acetate or " safety film " had been introduced by Kodak in 1908, at first it found only a few special applications as an alternative to the hazardous nitrate film, which had

6305-403: The introduction of automated photo printing equipment. After a transition period centered around 1995–2005, color film was relegated to a niche market by inexpensive multi-megapixel digital cameras. Film continues to be the preference of some photographers because of its distinctive "look". In 1981, Sony unveiled the first consumer camera to use a charge-coupled device for imaging, eliminating

6402-436: The inventor of photography. The fiction book Giphantie , published in 1760, by French author Tiphaigne de la Roche , described what can be interpreted as photography. In June 1802, British inventor Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance. He used paper or white leather treated with silver nitrate . Although he succeeded in capturing

6499-461: 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

6596-404: The late 1910s they were not available in the large formats preferred by most professional photographers, so the new medium did not immediately or completely replace the old. Because of the superior dimensional stability of glass, the use of plates for some scientific applications, such as astrophotography , continued into the 1990s, and in the niche field of laser holography , it has persisted into

6693-459: 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

6790-722: The need for film: the Sony Mavica . While the Mavica saved images to disk, the images were displayed on television, and the camera was not fully digital. The first digital camera to both record and save images in a digital format was the Fujix DS-1P created by Fujifilm in 1988. In 1991, Kodak unveiled the DCS 100 , the first commercially available digital single-lens reflex camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography

6887-415: The new field. He invented the cyanotype process, later familiar as the "blueprint". He was the first to use the terms "photography", "negative" and "positive". He had discovered in 1819 that sodium thiosulphate was a solvent of silver halides, and in 1839 he informed Talbot (and, indirectly, Daguerre) that it could be used to "fix" silver-halide-based photographs and make them completely light-fast. He made

6984-522: 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

7081-555: The overall sensitivity of emulsions steadily reduced the once-prohibitive long exposure times required for color, bringing it ever closer to commercial viability. Autochrome , the first commercially successful color process, was introduced by the Lumière brothers in 1907. Autochrome plates incorporated a mosaic color filter layer made of dyed grains of potato starch , which allowed the three color components to be recorded as adjacent microscopic image fragments. After an Autochrome plate

7178-848: 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

7275-535: The present day, as daguerreotypes could only be replicated by rephotographing them with a camera. Talbot's famous tiny paper negative of the Oriel window in Lacock Abbey , one of a number of camera photographs he made in the summer of 1835, may be the oldest camera negative in existence. In March 1837, Steinheil, along with Franz von Kobell , used silver chloride and a cardboard camera to make pictures in negative of

7372-412: 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

7469-1087: The process. The cyanotype process, for example, produces an image composed of blue tones. The albumen print process, publicly revealed in 1847, produces brownish tones. Many photographers continue to produce some monochrome images, sometimes because of the established archival permanence of well-processed silver-halide-based materials. Some full-color digital images are processed using a variety of techniques to create black-and-white results, and some manufacturers produce digital cameras that exclusively shoot monochrome. Monochrome printing or electronic display can be used to salvage certain photographs taken in color which are unsatisfactory in their original form; sometimes when presented as black-and-white or single-color-toned images they are found to be more effective. Although color photography has long predominated, monochrome images are still produced, mostly for artistic reasons. Almost all digital cameras have an option to shoot in monochrome, and almost all image editing software can combine or selectively discard RGB color channels to produce

7566-461: The same organisation—that may or may not incorporate a number of different forest features (e.g., stand height, canopy cover, strip width, inclusion of grasses, and rates of growth for timber production ). Areas without trees may be classified as forest cover "if the intention is to re-plant" ( UK and Ireland ), while areas with many trees may not be labelled as forest "if the trees are not growing fast enough" ( Norway and Finland ). "Land cover"

7663-514: The scene, appeared as brightly colored ghosts in the resulting projected or printed images. Implementation of color photography was hindered by the limited sensitivity of early photographic materials, which were mostly sensitive to blue, only slightly sensitive to green, and virtually insensitive to red. The discovery of dye sensitization by photochemist Hermann Vogel in 1873 suddenly made it possible to add sensitivity to green, yellow and even red. Improved color sensitizers and ongoing improvements in

7760-410: The shadows of objects placed on the surface in direct sunlight, and even made shadow copies of paintings on glass, it was reported in 1802 that "the images formed by means of a camera obscura have been found too faint to produce, in any moderate time, an effect upon the nitrate of silver." The shadow images eventually darkened all over. The first permanent photoetching was an image produced in 1822 by

7857-423: 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

7954-461: The target areas. Land cover change detection and mapping is a key component of interdisciplinary land change science , which uses it to determine the consequences of land change on climate. 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

8051-533: The techniques described in Ibn al-Haytham 's Book of Optics are capable of producing primitive photographs using medieval materials. Daniele Barbaro described a diaphragm in 1566. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. Around 1717, Johann Heinrich Schulze used a light-sensitive slurry to capture images of cut-out letters on a bottle and on that basis many German sources and some international ones credit Schulze as

8148-406: The term remote sensing generally refers to 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

8245-615: 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

8342-518: The three images made in their complementary colors , a subtractive method of color reproduction pioneered by Louis Ducos du Hauron in the late 1860s. Russian photographer Sergei Mikhailovich Prokudin-Gorskii made extensive use of this color separation technique, employing a special camera which successively exposed the three color-filtered images on different parts of an oblong plate . Because his exposures were not simultaneous, unsteady subjects exhibited color "fringes" or, if rapidly moving through

8439-537: The word, photographie , in private notes which a Brazilian historian believes were written in 1834. This claim is widely reported but is not yet largely recognized internationally. The first use of the word by Florence became widely known after the research of Boris Kossoy in 1980. The German newspaper Vossische Zeitung of 25 February 1839 contained an article entitled Photographie , discussing several priority claims – especially Henry Fox Talbot 's – regarding Daguerre's claim of invention. The article

8536-486: Was monochrome , or black-and-white . Even after color film was readily available, black-and-white photography continued to dominate for decades, due to its lower cost, chemical stability, and its "classic" photographic look. The tones and contrast between light and dark areas define black-and-white photography. Monochromatic pictures are not necessarily composed of pure blacks, whites, and intermediate shades of gray but can involve shades of one particular hue depending on

8633-407: Was reversal processed to produce a positive transparency , the starch grains served to illuminate each fragment with the correct color and the tiny colored points blended together in the eye, synthesizing the color of the subject by the additive method . Autochrome plates were one of several varieties of additive color screen plates and films marketed between the 1890s and the 1950s. Kodachrome ,

8730-409: Was born. Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. An important difference between digital and chemical photography is that chemical photography resists photo manipulation because it involves film and photographic paper , while digital imaging is a highly manipulative medium. This difference allows for

8827-507: Was created from the Greek roots φωτός ( phōtós ), genitive of φῶς ( phōs ), "light" and γραφή ( graphé ) "representation by means of lines" or "drawing", together meaning "drawing with light". Several people may have coined the same new term from these roots independently. Hércules Florence , a French painter and inventor living in Campinas, Brazil , used the French form of

8924-579: 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

9021-405: Was measured in minutes instead of hours. Daguerre took the earliest confirmed photograph of a person in 1838 while capturing a view of a Paris street: unlike the other pedestrian and horse-drawn traffic on the busy boulevard, which appears deserted, one man having his boots polished stood sufficiently still throughout the several-minutes-long exposure to be visible. The existence of Daguerre's process

9118-399: Was more practical. In partnership with Louis Daguerre , he worked out post-exposure processing methods that produced visually superior results and replaced the bitumen with a more light-sensitive resin, but hours of exposure in the camera were still required. With an eye to eventual commercial exploitation, the partners opted for total secrecy. Niépce died in 1833 and Daguerre then redirected

9215-548: 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

9312-403: Was publicly announced, without details, on 7 January 1839. The news created an international sensation. France soon agreed to pay Daguerre a pension in exchange for the right to present his invention to the world as the gift of France, which occurred when complete working instructions were unveiled on 19 August 1839. In that same year, American photographer Robert Cornelius is credited with taking

9409-438: Was to take three separate black-and-white photographs through red, green and blue filters . This provides the photographer with the three basic channels required to recreate a color image. Transparent prints of the images could be projected through similar color filters and superimposed on the projection screen, an additive method of color reproduction. A color print on paper could be produced by superimposing carbon prints of

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