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48-447: The GHSL processing framework uses a range of data, including census data , archives of fine-scale global satellite imagery , and voluntarily provided geographic information . Data is processed automatically to produce analytics and knowledge that methodically and objectively describe the existence of people and developed infrastructure. The GHSL maps human presence on Earth, sourcing information from 1975 and up to 2030. In 2010–2011,

96-474: 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

144-407: A 3.1-megapixel image. The image would be a very low quality image (72ppi) if printed at about 28.5 inches wide, but a very good quality (300ppi) image if printed at about 7 inches wide. The number of photodiodes in a color digital camera image sensor is often a multiple of the number of pixels in the image it produces, because information from an array of color image sensors is used to reconstruct

192-421: A particle's coordinates imposed by the measurement or existence of information regarding its momentum to any degree of precision. This fundamental limitation can, in turn, be a factor in the maximum imaging resolution at subatomic scales, as can be encountered using scanning electron microscopes . Radiometric resolution determines how finely a system can represent or distinguish differences of intensity , and

240-765: A routine and operational monitoring system . This geography -related article is a stub . You can help Misplaced Pages by expanding it . Satellite imagery Satellite images (also Earth observation imagery , spaceborne photography , or simply satellite photo ) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell images by licensing them to governments and businesses such as Apple Maps and Google Maps . 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

288-468: A specific geographic location." Image resolution Image resolution is the level of detail of an image . The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how close lines can be to each other and still be visibly resolved . Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to

336-422: 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,

384-593: 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

432-476: Is a list of traditional, analogue horizontal resolutions for various media. The list only includes popular formats, not rare formats, and all values are approximate, because the actual quality can vary machine-to-machine or tape-to-tape. For ease-of-comparison, all values are for the NTSC system. (For PAL systems, replace 480 with 576.) Analog formats usually had less chroma resolution. Many cameras and displays offset

480-578: 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

528-753: 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

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576-474: Is an illustration of how the same image might appear at different pixel resolutions, if the pixels were poorly rendered as sharp squares (normally, a smooth image reconstruction from pixels would be preferred, but for illustration of pixels, the sharp squares make the point better). [REDACTED] An image that is 2048 pixels in width and 1536 pixels in height has a total of 2048×1536 = 3,145,728 pixels or 3.1 megapixels. One could refer to it as 2048 by 1536 or

624-489: 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,

672-491: Is called spatial resolution, and it depends on properties of the system creating the image, not just the pixel resolution in pixels per inch (ppi). For practical purposes the clarity of the image is decided by its spatial resolution, not the number of pixels in an image. In effect, spatial resolution is the number of independent pixel values per unit length. The spatial resolution of consumer displays ranges from 50 to 800 pixel lines per inch. With scanners, optical resolution

720-420: 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 ]

768-445: 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

816-409: Is often considered equivalent to pixel count in digital imaging , though international standards in the digital camera field specify it should instead be called "Number of Total Pixels" in relation to image sensors, and as "Number of Recorded Pixels" for what is fully captured. Hence, CIPA DCG-001 calls for notation such as "Number of Recorded Pixels 1000 × 1500". According to the same standards,

864-493: Is sometimes used to distinguish spatial resolution from the number of pixels per inch. In remote sensing , spatial resolution is typically limited by diffraction , as well as by aberrations, imperfect focus, and atmospheric distortion. The ground sample distance (GSD) of an image, the pixel spacing on the Earth's surface, is typically considerably smaller than the resolvable spot size. In astronomy , one often measures spatial resolution in data points per arcsecond subtended at

912-490: 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

960-418: 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

1008-435: Is the precision of a measurement with respect to time. Movie cameras and high-speed cameras can resolve events at different points in time. The time resolution used for movies is usually 24 to 48 frames per second (frames/s), whereas high-speed cameras may resolve 50 to 300 frames/s, or even more. The Heisenberg uncertainty principle describes the fundamental limit on the maximum spatial resolution of information about

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1056-430: Is usually expressed as a number of levels or a number of bits , for example 8 bits or 256 levels that is typical of computer image files. The higher the radiometric resolution, the better subtle differences of intensity or reflectivity can be represented, at least in theory. In practice, the effective radiometric resolution is typically limited by the noise level, rather than by the number of bits of representation. This

1104-451: 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

1152-479: The "Number of Effective Pixels" that an image sensor or digital camera has is the count of pixel sensors that contribute to the final image (including pixels not in said image but nevertheless support the image filtering process), as opposed to the number of total pixels , which includes unused or light-shielded pixels around the edges. An image of N pixels height by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when

1200-726: The JRC Directorate E "Space, Security & Migration" developed the initial version of the GHSL concept, which was used to create the Atlases of the Human Planet. The JRC is currently supporting GHSL activities through its scientific working plans and is collaborating with the Directorate-General for Regional and Urban Policy (DG REGIO) and the Directorate-General for Defence Industry and Space (DG DEFIS) to develop

1248-580: 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

1296-575: The color of a single pixel. The image has to be interpolated or demosaiced to produce all three colors for each output pixel. The terms blurriness and sharpness are used for digital images but other descriptors are used to reference the hardware capturing and displaying the images. Spatial resolution in radiology is the ability of the imaging modality to differentiate two objects. Low spatial resolution techniques will be unable to differentiate between two objects that are relatively close together. The measure of how closely lines can be resolved in an image

1344-422: 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

1392-565: 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

1440-408: The hardware capturing and displaying the images. Spectral resolution is the ability to resolve spectral features and bands into their separate components. Color images distinguish light of different spectra . Multispectral images can resolve even finer differences of spectrum or wavelength by measuring and storing more than the traditional 3 of common RGB color images. Temporal resolution (TR)

1488-518: 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

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1536-442: The latter (although more difficult to achieve) is key to visualizing how individual atoms interact. In Stereoscopic 3D images, spatial resolution could be defined as the spatial information recorded or captured by two viewpoints of a stereo camera (left and right camera). Pixel encoding limits the information stored in a digital image, and the term color profile is used for digital images but other descriptors are used to reference

1584-637: 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

1632-520: 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

1680-549: The overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtense. Instead of single lines, line pairs are often used, composed of a dark line and an adjacent light line; for example, a resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm). Photographic lens are most often quoted in line pairs per millimeter. The resolution of digital cameras can be described in many different ways. The term resolution

1728-814: The pixel counts are referred to as "resolution", the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 7680 × 6876 . Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels , which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions , but they are widely referred to as such; they serve as upper bounds on image resolution. Below

1776-585: The point of observation, because the physical distance between objects in the image depends on their distance away and this varies widely with the object of interest. On the other hand, in electron microscopy , line or fringe resolution is the minimum separation detectable between adjacent parallel lines (e.g. between planes of atoms), whereas point resolution is instead the minimum separation between adjacent points that can be both detected and interpreted e.g. as adjacent columns of atoms, for instance. The former often helps one detect periodicity in specimens, whereas

1824-620: 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

1872-447: 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

1920-405: 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

1968-524: 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

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2016-424: 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

2064-407: 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

2112-589: 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

2160-533: 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

2208-542: 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

2256-489: 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

2304-589: 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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