1.
Military colours, standards and guidons
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The Roman Empire also made battle standards a part of their vast armies. It was formalized in the armies of Europe in the High Middle Ages, as armies became trained and adopted set formations, each regiments ability to keep its formation was potentially critical to its, and therefore its armys, success. In the chaos of battle, not least due to the amount of dust and smoke on a battlefield, Regimental flags are generally awarded to a regiment by a head-of-State during a ceremony. They were therefore treated with reverence as they represented the honour, Colours may be inscribed with the names of battles or other symbols representing former achievements. Regiments tended to adopt colour guards, composed of experienced or élite soldiers, as a result, the capture of an enemys standard was considered as a great feat of arms. They are never capriciously destroyed – when too old to use they are replaced and then laid-up in museums, religious buildings and other places of significance to their regiment. However, in most modern armies, standing orders now call for the Colours to be destroyed if they are ever in jeopardy of being captured by the enemy. Due to the advent of modern weapons, and subsequent changes in tactics, Colours are no longer carried into battle, but continue to be used at events of formal character. The Armed Forces of the Argentine Republics military Colours of the Argentine Army, Argentine Navy and Argentine Air Force are the Flag of Argentina as the National War Colour and the Unit Colour. The National War Colour is a variation of the Argentine national flag made for use, while the Unit Colour differs per service arm. Only the Regiment of Patricians uses company colors, cadet squadron colours are used by the Argentine Air Force Academy. Units of the Brazilian Armed Forces carry a stand of two Colours, differing per service, the standard of the Army measures 80 ×120 cm, white with the Army coat of arms in the centre, trimmed with gold fringe. The name of the service is inscribed in letters on a green scroll beneath the shield. Above the shield is a helmet with red and sky blue mantling. The staff is topped by a nickel-plated lance-head finial,32 cm high, ten red streamers with campaign honours inscribed in sky blue letters are also attached below the lance-head. The staff is 212 cm long, not including the lance-head and it is covered in sky blue velvet with a red spiral strip. The colour belt is 10 cm in width, covered with sky blue velvet with red velvet stripes, the Navys flag uses dark blue colours, the Air Force flag ultramarine blue. Brazilian military units also carry the flag as a National Colour
2.
False flag
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While Kormoran was fatally damaged in the engagement and its crew captured the outcome represented a considerable psychological victory for the Germans. In December 1922–February 1923, Rules concerning the Control of Wireless Telegraphy in Time of War and Air Warfare, drafted by a commission of jurists at the Hague regulates, a military aircraft must carry an exterior mark indicating its nationality and its military character. The use of false exterior marks is forbidden, during the trial, a number of arguments were advanced to substantiate this position and the German and U. S. military seem to have been in agreement. The foregoing rule, does not prohibit such use, but does prohibit their improper use and it is certainly forbidden to make use of them during a combat. Before opening fire upon the enemy, they must be discarded, the American Soldiers Handbook was also quoted by Defense Counsel, The use of the enemy flag, insignia, and uniform is permitted under some circumstances. They are not to be used during fighting, and if used in order to approach the enemy without drawing fire. Subsequently, the outcome of the trial has been codified in the 1977 Protocol Additional to the Geneva Conventions of 12 August 1949 and it is prohibited to kill, injure, or capture an adversary by resort to perfidy. Ruses of war are not prohibited, the following are examples of such ruses, the use of camouflage, decoys, mock operations and disinformation. It is prohibited to use of the distinctive emblem of the United Nations. It is prohibited to use in an armed conflict of the flags or military emblems. It is prohibited to use of the flags or military emblems, insignia or uniforms of adverse Parties while engaging in attacks or in order to shield, favour. A false flag in the domain is slightly different and easier to perpetrate than in other physical theaters of war. This misdirection tactic can cause misattribution or misperception which can lead to retaliation against the wrong adversary, in 1788, the head tailor at the Royal Swedish Opera received an order to sew a number of Russian military uniforms. These were then used by the Swedes to stage an attack on Puumala and this caused an outrage in Stockholm and impressed the Riksdag of the Estates, the Swedish national assembly, who until then had refused to agree to an offensive war against Russia. The Puumala incident allowed King Gustav III of Sweden, who lacked the authority to initiate unprovoked hostilities without the Estates consent. In September 1931, Japanese officers fabricated a pretext for invading Manchuria by blowing up a section of railway, the Gleiwitz incident in 1939 involved Reinhard Heydrich fabricating evidence of a Polish attack against Germany to mobilize German public opinion for war and to justify the war with Poland. Alfred Naujocks was a key organiser of the operation orders from Heydrich. It led to the deaths of Nazi concentration camp victims who were dressed as German soldiers and this, along with other false flag operations in Operation Himmler, would be used to mobilize support from the German population for the start of World War II in Europe
3.
Optical filter
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Filters mostly belong to one of two categories. The simplest, physically, is the filter, then there are interference or dichroic filters. Optical filters selectively transmit light in a range of wavelengths. They can usually pass long wavelengths only, short wavelengths only, or a band of wavelengths, the passband may be narrower or wider, the transition or cutoff between maximal and minimal transmission can be sharp or gradual. Optical filters are used in photography, in many optical instruments. Optical filters are essential in fluorescence applications such as fluorescence microscopy. Photographic filters are a case of optical filters, and much of the material here applies. Some photographic effect filters, such as star effect filters, are not relevant to scientific work, absorptive filters are usually made from glass to which various inorganic or organic compounds have been added. These compounds absorb some wavelengths of light while transmitting others, the compounds can also be added to plastic to produce gel filters, which are lighter and cheaper than glass-based filters. Alternately, dichroic filters can be made by coating a substrate with a series of optical coatings. Dichroic filters usually reflect the unwanted portion of the light and transmit the remainder, Dichroic filters use the principle of interference. Their layers form a series of reflective cavities that resonate with the desired wavelengths. Other wavelengths destructively cancel or reflect as the peaks and troughs of the waves overlap, Dichroic filters are particularly suited for precise scientific work, since their exact colour range can be controlled by the thickness and sequence of the coatings. They are usually more expensive and delicate than absorption filters. They can be used in such as the dichroic prism of a camera to separate a beam of light into different coloured components. The basic scientific instrument of this type is a Fabry–Pérot interferometer and it uses two mirrors to establish a resonating cavity. It passes wavelengths that are a multiple of the resonance frequency. Etalons are another variation, transparent cubes or fibers whose polished ends form mirrors tuned to resonate with specific wavelengths and these are often used to separate channels in telecommunications networks that use wavelength division multiplexing on long-haul optic fibers
4.
Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
5.
Color
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Color or colour is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue. This perception of color derives from the stimulation of cells in the human eye by electromagnetic radiation in the spectrum of light. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them and this reflection is governed by the objects physical properties such as light absorption, emission spectra, etc. By defining a color space, colors can be identified numerically by coordinates, there may also be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a colours colorfulness). The photo-receptivity of the eyes of species also varies considerably from our own. Honeybees and bumblebees for instance have trichromatic color vision sensitive to ultraviolet but is insensitive to red, papilio butterflies possess six types of photoreceptors and may have pentachromatic vision. The most complex color vision system in the kingdom has been found in stomatopods with up to 12 spectral receptor types thought to work as multiple dichromatic units. The science of color is sometimes called chromatics, colorimetry, or simply color science and it includes the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range. Electromagnetic radiation is characterized by its wavelength and its intensity, when the wavelength is within the visible spectrum, it is known as visible light. Most light sources emit light at different wavelengths, a sources spectrum is a distribution giving its intensity at each wavelength. Although the spectrum of light arriving at the eye from a given direction determines the color sensation in that direction, in each such class the members are called metamers of the color in question. The table at right shows approximate frequencies and wavelengths for various pure spectral colors, the wavelengths listed are as measured in air or vacuum. A common list identifies six main bands, red, orange, yellow, green, blue, Newtons conception included a seventh color, indigo, between blue and violet. It is possible that what Newton referred to as blue is nearer to what today is known as cyan, the color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Some objects not only light, but also transmit light or emit light themselves. This effect is known as color constancy, opaque objects that do not reflect specularly have their color determined by which wavelengths of light they scatter strongly. If objects scatter all wavelengths with roughly equal strength, they appear white, if they absorb all wavelengths, they appear black. Opaque objects that reflect light of different wavelengths with different efficiencies look like mirrors tinted with colors determined by those differences
6.
Signal processing
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According to Alan V. Oppenheim and Ronald W. Schafer, the principles of signal processing can be found in the classical numerical analysis techniques of the 17th century. Oppenheim and Schafer further state that the digitalization or digital refinement of techniques can be found in the digital control systems of the 1940s and 1950s. Feature extraction, such as understanding and speech recognition. Quality improvement, such as reduction, image enhancement. Including audio compression, image compression, and video compression and this involves linear electronic circuits as well as non-linear ones. The former are, for instance, passive filters, active filters, additive mixers, integrators, non-linear circuits include compandors, multiplicators, voltage-controlled filters, voltage-controlled oscillators and phase-locked loops. Continuous-time signal processing is for signals that vary with the change of continuous domain, the methods of signal processing include time domain, frequency domain, and complex frequency domain. This technology was a predecessor of digital processing, and is still used in advanced processing of gigahertz signals. Digital signal processing is the processing of digitized discrete-time sampled signals, processing is done by general-purpose computers or by digital circuits such as ASICs, field-programmable gate arrays or specialized digital signal processors. Typical arithmetical operations include fixed-point and floating-point, real-valued and complex-valued, other typical operations supported by the hardware are circular buffers and look-up tables. Examples of algorithms are the Fast Fourier transform, finite impulse response filter, Infinite impulse response filter, nonlinear signal processing involves the analysis and processing of signals produced from nonlinear systems and can be in the time, frequency, or spatio-temporal domains. Nonlinear systems can produce complex behaviors including bifurcations, chaos, harmonics
7.
Visible spectrum
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The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called light or simply light. A typical human eye will respond to wavelengths from about 390 to 700 nm, in terms of frequency, this corresponds to a band in the vicinity of 430–770 THz. The spectrum does not, however, contain all the colors that the human eyes, unsaturated colors such as pink, or purple variations such as magenta, are absent, for example, because they can be made only by a mix of multiple wavelengths. Colors containing only one wavelength are called pure colors or spectral colors. Visible wavelengths pass through the window, the region of the electromagnetic spectrum that allows wavelengths to pass largely unattenuated through the Earths atmosphere. An example of this phenomenon is that clean air scatters blue light more than red wavelengths, the optical window is also referred to as the visible window because it overlaps the human visible response spectrum. The near infrared window lies just out of the vision, as well as the Medium Wavelength IR window. In the 13th century, Roger Bacon theorized that rainbows were produced by a process to the passage of light through glass or crystal. In the 17th century, Isaac Newton discovered that prisms could disassemble and reassemble white light and he was the first to use the word spectrum in this sense in print in 1671 in describing his experiments in optics. The result is red light is bent less sharply than violet as it passes through the prism. Newton divided the spectrum into seven named colors, red, orange, yellow, green, blue, indigo, the human eye is relatively insensitive to indigos frequencies, and some people who have otherwise-good vision cannot distinguish indigo from blue and violet. For this reason, some commentators, including Isaac Asimov, have suggested that indigo should not be regarded as a color in its own right. However, the evidence indicates that what Newton meant by indigo, comparing Newtons observation of prismatic colors to a color image of the visible light spectrum shows that indigo corresponds to what is today called blue, whereas blue corresponds to cyan. In the 18th century, Goethe wrote about optical spectra in his Theory of Colours, Goethe used the word spectrum to designate a ghostly optical afterimage, as did Schopenhauer in On Vision and Colors. Goethe argued that the spectrum was a compound phenomenon. Where Newton narrowed the beam of light to isolate the phenomenon, Goethe observed that a wider aperture produces not a spectrum but rather reddish-yellow, the spectrum appears only when these edges are close enough to overlap. Young was the first to measure the wavelengths of different colors of light, the connection between the visible spectrum and color vision was explored by Thomas Young and Hermann von Helmholtz in the early 19th century
8.
Electromagnetic spectrum
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The electromagnetic spectrum is the collective term for all known frequencies and their linked wavelengths of the known photons. The electromagnetic spectrum of an object has a different meaning, and is instead the characteristic distribution of radiation emitted or absorbed by that particular object. Visible light lies toward the end, with wavelengths from 400 to 700 nanometres. The limit for long wavelengths is the size of the universe itself, until the middle of the 20th century it was believed by most physicists that this spectrum was infinite and continuous. Nearly all types of radiation can be used for spectroscopy, to study. Other technological uses are described under electromagnetic radiation, for most of history, visible light was the only known part of the electromagnetic spectrum. The ancient Greeks recognized that light traveled in straight lines and studied some of its properties, the study of light continued, and during the 16th and 17th centuries conflicting theories regarded light as either a wave or a particle. The first discovery of electromagnetic radiation other than visible light came in 1800 and he was studying the temperature of different colors by moving a thermometer through light split by a prism. He noticed that the highest temperature was beyond red and he theorized that this temperature change was due to calorific rays that were a type of light ray that could not be seen. The next year, Johann Ritter, working at the end of the spectrum. These behaved similarly to visible light rays, but were beyond them in the spectrum. They were later renamed ultraviolet radiation, during the 1860s James Maxwell developed four partial differential equations for the electromagnetic field. Two of these equations predicted the possibility of, and behavior of, analyzing the speed of these theoretical waves, Maxwell realized that they must travel at a speed that was about the known speed of light. This startling coincidence in value led Maxwell to make the inference that light itself is a type of electromagnetic wave, maxwells equations predicted an infinite number of frequencies of electromagnetic waves, all traveling at the speed of light. This was the first indication of the existence of the electromagnetic spectrum. Maxwells predicted waves included waves at very low compared to infrared. Hertz found the waves and was able to infer that they traveled at the speed of light, Hertz also demonstrated that the new radiation could be both reflected and refracted by various dielectric media, in the same manner as light. For example, Hertz was able to focus the waves using a lens made of tree resin, in a later experiment, Hertz similarly produced and measured the properties of microwaves
9.
Photograph
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A photograph or photo is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic medium such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scenes visible wavelengths of light into a reproduction of what the eye would see. The process and practice of creating photographs is called photography, the word photograph was coined in 1839 by Sir John Herschel and is based on the Greek φῶς, meaning light, and γραφή, meaning drawing, writing, together meaning drawing with light. The first permanent photograph, a copy of an engraving, was made in 1822 using the bitumen-based heliography process developed by Nicéphore Niépce. In 1829 Niépce entered into a partnership with Louis Daguerre and the two collaborated to work out a similar but more sensitive and otherwise improved process, after Niépces death in 1833, Daguerre concentrated on silver halide-based alternatives. He named this first practical process for making photographs with a camera the daguerreotype and its existence was announced to the world on 7 January 1839 but working details were not made public until 19 August. Other inventors soon made improvements which reduced the exposure time from a few minutes to a few seconds, making portrait photography truly practical. The daguerreotype had shortcomings, notably the fragility of the image surface. Each was a unique opaque positive that could only be duplicated by copying it with a camera, inventors set about working out improved processes that would be more practical. By the end of the 1850s the daguerreotype had been replaced by the expensive and more easily viewed ambrotype and tintype. The mid-1930s saw the introduction of Kodachrome and Agfacolor Neu, the first easy-to-use color films of the modern multi-layer chromogenic type, the needs of the motion picture industry generated a number of special processes and systems, perhaps the best-known being the now-obsolete three-strip Technicolor process. Non-digital photographs are produced with a chemical process. In the two-step process the film captures a negative image. To produce an image, the negative is most commonly transferred onto photographic paper. Printing the negative onto transparent film stock is used to motion picture films. Alternatively, the film is processed to invert the negative image, such positive images are usually mounted in frames, called slides. Before recent advances in photography, transparencies were widely used by professionals because of their sharpness. Most photographs published in magazines were taken on color transparency film, originally, all photographs were monochromatic or hand-painted in color
10.
Information visualization
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Information visualization or information visualisation is the study of visual representations of abstract data to reinforce human cognition. The abstract data include both numerical and non-numerical data, such as text and geographic information, however, information visualization differs from scientific visualization, it’s infovis when the spatial representation is chosen, and it’s scivis when the spatial representation is given. The field of visualization has emerged from research in human-computer interaction, computer science, graphics, visual design, psychology. Information visualization focused on the creation of approaches for conveying information in intuitive ways. Data analysis is an part of all applied research and problem solving in industry. The most fundamental data analysis approaches are visualization, statistics, data mining, the analyst does not have to learn any sophisticated methods to be able to interpret the visualizations of the data. Information visualization is also a hypothesis generation scheme, which can be, the modern study of visualization started with computer graphics, which has from its beginning been used to study scientific problems. However, in its early days the lack of power often limited its usefulness. The recent emphasis on visualization started in 1987 with the issue of Computer Graphics on Visualization in Scientific Computing. Since then there have been several conferences and workshops, co-sponsored by the IEEE Computer Society and they have been devoted to the general topics of data visualisation, information visualization and scientific visualisation, and more specific areas such as volume visualization. In 1786, William Playfair published the first presentation graphics, the Craft of Information Visualization, Readings and Reflections. Stuart K. Card, Jock D. Mackinlay and Ben Shneiderman, Readings in Information Visualization, Using Vision to Think, Morgan Kaufmann Publishers. Jeffrey Heer, Stuart K. Card, James Landay, prefuse, a toolkit for interactive information visualization. In, ACM Human Factors in Computing Systems CHI2005, andreas Kerren, John T. Stasko, Jean-Daniel Fekete, and Chris North. Information Visualization – Human-Centered Issues and Perspectives, volume 4950 of LNCS State-of-the-Art Survey, Springer. Spence, Robert Information Visualization, Design for Interaction, Prentice Hall,2007, ISBN 0-13-206550-9
11.
Color depth
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For consumer video standards, such as High Efficiency Video Coding, the bit depth specifies the number of bits used for each color component. When referring to a pixel the concept can be defined as bits per pixel, which specifies the number of bits used. When referring to a component the concept can be defined as bits per component, bits per channel, bits per color. Color depth is one aspect of color representation, expressing how finely levels of color can be expressed. The definition of both color precision and gamut is accomplished with a color encoding specification which assigns a code value to a location in a color space. Comparison, same image on five different color depths, different looks, but also different file sizes. With the relatively low color depth, the value is typically a number representing the index into a color map or palette. The colors available in the palette itself may be fixed by the hardware or modifiable within the limits of the hardware, modifiable palettes are sometimes referred to as pseudocolor palettes. 1-bit color, monochrome, often black and white, compact Macintoshes, 2-bit color, CGA, gray-scale early NeXTstation, color Macintoshes, Atari ST. 12-bit color, some Silicon Graphics systems, Color NeXTstation systems, for example, in the ZX Spectrum, the picture is stored in a two-color format, but these two colors can be separately defined for each rectangular block of 8x8 pixels. A very limited but true direct color system, there are 3 bits for each of the R and G components, the normal human eye is less sensitive to the blue component than to the red or green, so it is assigned one bit less than the others. Used, amongst others, in the MSX2 system series of computers in the early to mid 1990s, do not confuse with an indexed color depth of 8bpp. High color supports 15/16-bit for three RGB colors, in 16-bit direct color, there can be 4 bits for each of the R, G, and B components, plus optionally 4 bits for alpha, enabling 4,096 different colors with 16 levels of transparency. Or in some systems there can be 5 bits per color component and 1 bit of alpha, or there can be 5 bits for red,6 bits for green and these color depths are sometimes used in small devices with a color display, such as mobile telephones. Variants with 5 or more bits per component are sometimes called high color. More expensive LCDs can display 24-bit or greater color depth, true color supports 24-bit for three RGB colors. Usually, true color is defined to mean 256 shades of red, green, the human eye can discriminate up to ten million colors. Color processing in the eye occurs through retinal cone cells which are of three types, although not corresponding to red, green and blue hues, true color can also refer to an RGB display-mode that does not need a color look-up table
12.
Color vision
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Color vision is the ability of an organism or machine to distinguish objects based on the wavelengths of the light they reflect, emit, or transmit. In essence, different people see the same illuminated object or light source in different ways, isaac Newton discovered that white light splits into its component colours when passed through a dispersive prism. Newton also found that he could recombine these colours by passing them through a different prism to make white light, the characteristic colours are, from long to short wavelengths, red, orange, yellow, green, blue, and purple. In very low levels, vision is scotopic, light is detected by rod cells of the retina. Rods are maximally sensitive to wavelengths near 500 nm, and play little, if any, in brighter light, such as daylight, vision is photopic, light is detected by cone cells which are responsible for colour vision. Cones are sensitive to a range of wavelengths, but are most sensitive to wavelengths near 555 nm, between these regions, mesopic vision comes into play and both rods and cones provide signals to the retinal ganglion cells. The shift in colour perception from dim light to daylight gives rise to differences known as the Purkinje effect, the perception of white is formed by the entire spectrum of visible light, or by mixing colours of just a few wavelengths in animals with few types of colour receptors. In humans, white light can be perceived by combining wavelengths such as red, green, perception of color begins with specialized retinal cells containing pigments with different spectral sensitivities, known as cone cells. In humans, there are three types of cones sensitive to three different spectra, resulting in color vision. Each individual cone contains pigments composed of opsin apoprotein, which is linked to either 11-cis-hydroretinal or more rarely 11-cis-dehydroretinal. The cones are conventionally labeled according to the ordering of the wavelengths of the peaks of their spectral sensitivities, short, medium and these three types do not correspond well to particular colors as we know them. For example, while the L cones have been referred to simply as red receptors, similarly, the S- and M-cones do not directly correspond to blue and green, although they are often described as such. The RGB color model, therefore, is a convenient means for representing color, two complementary theories of color vision are the trichromatic theory and the opponent process theory. Ewald Hering proposed the opponent process theory in 1872 and it states that the visual system interprets color in an antagonistic way, red vs. green, blue vs. yellow, black vs. white. Both theories are now accepted as valid, describing different stages in visual physiology, green ←→ Magenta and Blue ←→ Yellow are scales with mutually exclusive boundaries. In the same way that there cannot exist a slightly negative positive number, a range of wavelengths of light stimulates each of these receptor types to varying degrees. Yellowish-green light, for example, stimulates both L and M cones equally strongly, but only stimulates S-cones weakly, the brain combines the information from each type of receptor to give rise to different perceptions of different wavelengths of light. The opsins present in the L and M cones are encoded on the X chromosome, the OPN1LW gene, which codes for the opsin present in the L cones, is highly polymorphic
13.
Landsat program
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The Landsat program is the longest-running enterprise for acquisition of satellite imagery of Earth. On July 23,1972 the Earth Resources Technology Satellite was launched and this was eventually renamed to Landsat. The most recent, Landsat 8, was launched on February 11,2013, the instruments on the Landsat satellites have acquired millions of images. Landsat 7 data has eight spectral bands with spatial resolutions ranging from 15 to 60 meters, Landsat images are usually divided into scenes for easy downloading. Each Landsat scene is about 115 miles long and 115 miles wide, Hughes Santa Barbara Research Center initiated, designed, and fabricated the first three Multispectral Scanners in 1969, the same year man landed on the moon. The first prototype MSS was completed nine months, in the fall of 1970. It was tested by scanning Half Dome at Yosemite National Park, the program was initially called the Earth Resources Technology Satellites Program, which was used from 1966 to 1975. In 1975, the name was changed to Landsat and this occurred in 1985 when the Earth Observation Satellite Company, a partnership of Hughes Aircraft and RCA, was selected by NOAA to operate the Landsat system with a ten-year contract. EOSAT operated Landsat 4 and Landsat 5, had rights to market Landsat data. In 1989, this transition had not been completed when NOAAs funding for the Landsat program was due to run out. 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 the funding to NOAA. In 1992, various efforts were made to procure funding for follow on Landsats and continued operations, Landsat 6 was finally launched on October 5,1993, but was lost in a launch failure. Processing of Landsat 4 and 5 data was resumed by EOSAT in 1994, NASA finally launched Landsat 7 on April 15,1999. Timeline Landsat missions 1 through 5 carried the Landsat Multispectral Scanner and this construct ensured the secondary mirror would simply oscillate about the primary optic axis to maintain focus despite vibration inherent from the 360 mm beryllium scan mirror. This engineering solution allowed the United States to develop LANDSAT at least five years ahead of the French SPOT and this was a direct result of the commercialization efforts begun under the Carter administration, though finally completed under the Reagan administration. This main plate was assembled on a frame, then attached to the magnesium housing with helicoil fasteners. Key to the success of the multi spectral scanner was the scan monitor mounted on the underbelly of the magnesium housing, the beam struck the beryllium scan mirror seven times as it reflected seven times off the flat mirrors
14.
Chesapeake Bay
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It is the largest estuary in North America. With its northern portion in Maryland and the part in Virginia. More than 150 major rivers and streams flow into the bays 64, 299-square-mile drainage basin, the bay is approximately 200 miles long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocean. It is 2.8 miles wide at its narrowest and 30 miles at its widest, total shoreline including tributaries is 11,684 miles, circumnavigating a surface area of 4,479 square miles. Average depth is 21 feet, reaching a maximum of 174 feet, the bay is spanned twice, in Maryland by the Chesapeake Bay Bridge from Sandy Point to Kent Island and in Virginia by the Chesapeake Bay Bridge-Tunnel connecting Virginia Beach to Cape Charles. Known for both its beauty and bounty, the bay became emptier, with crabs, oysters. Recent restoration efforts begun in the 1990s have been ongoing and show potential for growth of the oyster population. The health of the Chesapeake Bay improved in 2015, marking three years of gains over the past four years, according to a new report by the University of Maryland, the word Chesepiooc is an Algonquian word referring to a village at a big river. It is the seventh oldest surviving English place-name in the U. S. first applied as Chesepiook by explorers heading north from the Roanoke Colony into a Chesapeake tributary in 1585 or 1586. The name may refer to the Chesepian or Chesapeake people. They occupied an area which is now the Norfolk, Portsmouth, Chesapeake, in 2005, Algonquian linguist Blair Rudes helped to dispel one of the areas most widely held beliefs, that Chesapeake means something like great shellfish bay. The name might actually have meant something like great water, or it might have just referred to a location at the bays mouth. In addition, the name is almost always prefixed by the in usage by local residents, The Chesapeake, The Chesapeake Bay, the Chesapeake Bay is an estuary to the North Atlantic, lying between the Delmarva Peninsula to the east and the North American mainland to the west. It is the ria, or drowned valley, of the Susquehanna River and it is not a fjord, because the Laurentide Ice Sheet never reached as far south as the northernmost point on the bay. The large rivers entering the bay from the west have broad mouths and are extensions of the ria for miles up the course of each river. The bay was formed starting about 10,000 years ago when rising sea levels at the end of the last ice age flooded the Susquehanna River valley. Parts of the bay, especially the Calvert County, Maryland and these cliffs, generally known as Calvert Cliffs, are famous for their fossils, especially fossilized shark teeth which are commonly found washed up on the beaches next to the cliffs. Scientists Cliffs is a community in Calvert County named for the desire to create a retreat for scientists when the community was founded in 1935
15.
Baltimore
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Baltimore is the largest city in the U. S. state of Maryland, and the 29th-most populous city in the country. It was established by the Constitution of Maryland and is not part of any county, thus, it is the largest independent city in the United States, with a population of 621,849 as of 2015. As of 2010, the population of the Baltimore Metropolitan Area was 2.7 million, founded in 1729, Baltimore is the second largest seaport in the Mid-Atlantic. Baltimores Inner Harbor was once the leading port of entry for immigrants to the United States. With hundreds of identified districts, Baltimore has been dubbed a city of neighborhoods, in the War of 1812, Francis Scott Key wrote The Star-Spangled Banner, later the American national anthem, in Baltimore. More than 65,000 properties, or roughly one in three buildings in the city, are listed on the National Register, more than any city in the nation. The city has 289 properties listed on the National Register of Historic Places, the historical records of the government of Baltimore are located at the Baltimore City Archives. The city is named after Cecil Calvert, second Lord Baltimore, of the Irish House of Lords, Baltimore Manor was the name of the estate in County Longford on which the Calvert family lived in Ireland. Baltimore is an anglicization of the Irish name Baile an Tí Mhóir, in 1608, Captain John Smith traveled 210 miles from Jamestown to the uppermost Chesapeake Bay, leading the first European expedition to the Patapsco River. The name Patapsco is derived from pota-psk-ut, which translates to backwater or tide covered with froth in Algonquian dialect, a quarter century after John Smiths voyage, English colonists began to settle in Maryland. The area constituting the modern City of Baltimore and its area was first settled by David Jones in 1661. He claimed the area today as Harbor East on the east bank of the Jones Falls stream. In the early 1600s, the immediate Baltimore vicinity was populated, if at all. The Baltimore area had been inhabited by Native Americans since at least the 10th millennium BC, one Paleo-Indian site and several Archaic period and Woodland period archaeological sites have been identified in Baltimore, including four from the Late Woodland period. During the Late Woodland period, the culture that is called the Potomac Creek complex resided in the area from Baltimore to the Rappahannock River in Virginia. It was located on the Bush River on land that in 1773 became part of Harford County, in 1674, the General Assembly passed An Act for erecting a Court-house and Prison in each County within this Province. The site of the house and jail for Baltimore County was evidently Old Baltimore near the Bush River. In 1683, the General Assembly passed An Act for Advancement of Trade to establish towns, ports, one of the towns established by the act in Baltimore County was on Bush River, on Town Land, near the Court-House
16.
RGB color model
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The RGB color model is an additive color model in which red, green and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three primary colors, red, green and blue. Before the electronic age, the RGB color model already had a theory behind it. Thus an RGB value does not define the same color across devices without some kind of color management, typical RGB input devices are color TV and video cameras, image scanners, video games, and digital cameras. Typical RGB output devices are TV sets of technologies, computer and mobile phone displays, video projectors, multicolor LED displays. Color printers, on the hand are not RGB devices. This article discusses concepts common to all the different color spaces that use the RGB color model, to form a color with RGB, three light beams must be superimposed. Each of the three beams is called a component of color, and each of them can have an arbitrary intensity, from fully off to fully on. The RGB color model is additive in the sense that the three beams are added together, and their light spectra add, wavelength for wavelength. This is essentially opposite to the color model that applies to paints, inks, dyes. When the intensities for all the components are the same, the result is a shade of gray, darker or lighter depending on the intensity. When the intensities are different, the result is a colorized hue, a secondary color is formed by the sum of two primary colors of equal intensity, cyan is green+blue, magenta is red+blue, and yellow is red+green. The RGB color model itself does not define what is meant by red, green and blue colorimetrically, and so the results of mixing them are not specified as absolute, but relative to the primary colors. When the exact chromaticities of the red, green and blue primaries are defined, the normal three kinds of light-sensitive photoreceptor cells in the human eye respond most to yellow, green, and violet light. As an example, suppose that light in the range of wavelengths enters the eye. Light of these wavelengths would activate both the medium and long wavelength cones of the retina, but not equally—the long-wavelength cells will respond more, the difference in the response can be detected by the brain, and this difference is the basis of our perception of orange. Thus, the appearance of an object results from light from the object entering our eye and stimulating the different cones simultaneously. The first experiments with RGB in early color photography were made in 1861 by Maxwell himself, to reproduce the color photograph, three matching projections over a screen in a dark room were necessary
17.
Infrared
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It extends from the nominal red edge of the visible spectrum at 700 nanometers, to 1000000 nm. Most of the radiation emitted by objects near room temperature is infrared. Like all EMR, IR carries radiant energy, and behaves both like a wave and like its quantum particle, the photon, slightly more than half of the total energy from the Sun was eventually found to arrive on Earth in the form of infrared. The balance between absorbed and emitted infrared radiation has an effect on Earths climate. Infrared radiation is emitted or absorbed by molecules when they change their rotational-vibrational movements and it excites vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states for molecules of the proper symmetry. Infrared spectroscopy examines absorption and transmission of photons in the infrared range, Infrared radiation is used in industrial, scientific, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected, Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatuses. Thermal-infrared imaging is used extensively for military and civilian purposes, military applications include target acquisition, surveillance, night vision, homing, and tracking. Humans at normal body temperature radiate chiefly at wavelengths around 10 μm, Infrared radiation extends from the nominal red edge of the visible spectrum at 700 nanometers to 1 mm. This range of wavelengths corresponds to a range of approximately 430 THz down to 300 GHz. Below infrared is the portion of the electromagnetic spectrum. Sunlight, at a temperature of 5,780 kelvins, is composed of near thermal-spectrum radiation that is slightly more than half infrared. At zenith, sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level, of this energy,527 watts is infrared radiation,445 watts is visible light, and 32 watts is ultraviolet radiation. Nearly all the radiation in sunlight is near infrared, shorter than 4 micrometers. On the surface of Earth, at far lower temperatures than the surface of the Sun, almost all thermal radiation consists of infrared in mid-infrared region, much longer than in sunlight. Of these natural thermal radiation processes only lightning and natural fires are hot enough to produce much visible energy, thermal infrared radiation also has a maximum emission wavelength, which is inversely proportional to the absolute temperature of object, in accordance with Wiens displacement law. Therefore, the band is often subdivided into smaller sections. Due to the nature of the blackbody radiation curves, typical hot objects, such as exhaust pipes, the three regions are used for observation of different temperature ranges, and hence different environments in space
18.
Endurance (crater)
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Endurance is an impact crater lying situated within the Margaritifer Sinus quadrangle region of the planet Mars. This crater was visited by the Opportunity rover from May until December 2004, the rover entered the crater interior on its 134th mission sol, and exited on the 315th sol. During this time it traversed various obstacles, steep inclines, after arriving at the crater, Opportunity performed a survey of the crater to plan the further steps in exploring the local geology. A site dubbed Karatepe was chosen to enter the crater and investigate the layering of the bedrock, the picture to the right shows changes in the color of the bedrock layers. The layer A is closer to the rover and higher than the layers B to E. Texture, thus scientists infer that the age of these layers is following a similar pattern, with the higher layers being younger than the lower layers. Opportunity then went farther down into the crater to investigate the sand dunes, various rock outcrops were investigated while the rover descended. It was decided not to drive into the dunes, for fear the rover might get stuck permanently, instead, Opportunity did some work on some rocks surrounding the dunes before heading back up to the rim of the crater. On the way, it encountered a boulder, nicknamed Wopmay, the rover then headed off to Burns Cliff. Burns Cliff, named for the late mineralogist Roger Burns of MIT, was studied closely by Opportunity, high amounts of slippage prevented the rover from using its robotic arm, however high resolution imaging was conducted with the Pancam. It shows layers of sediment that might indicate deposition by a liquid, the layers in the cliff would later be followed south of the crater to identify it as a geologic formation, in this case the Burns Formation. These names are not official until made so by the International Astronomical Union, Burns Cliff was the final science stop inside Endurance. The rover had some trouble making it out, noticing slippage, leaving Endurance it headed for its heat shield where it would find the Meridiani Planum meteorite, which happened to be the first meteorite discovered on another planet. Opportunity spent about half a year exploring Endurance. Exploration of Mars Geography of Mars List of craters on Mars Grotzinger, J. P. Arvidson, R, Belliii, J, Calvin, W, Clark, B, Fike, D, Golombek, M, Greeley, R, et al. Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars
19.
Mars
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Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is referred to as the Red Planet because the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth. The rotational period and seasonal cycles of Mars are likewise similar to those of Earth, Mars is the site of Olympus Mons, the largest volcano and second-highest known mountain in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the northern hemisphere covers 40% of the planet, Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan, there are ongoing investigations assessing the past habitability potential of Mars, as well as the possibility of extant life. Future astrobiology missions are planned, including the Mars 2020 and ExoMars rovers, liquid water cannot exist on the surface of Mars due to low atmospheric pressure, which is about 6⁄1000 that of the Earths, except at the lowest elevations for short periods. The two polar ice caps appear to be largely of water. The volume of ice in the south polar ice cap, if melted. On November 22,2016, NASA reported finding a large amount of ice in the Utopia Planitia region of Mars. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior, Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Its apparent magnitude reaches −2.91, which is surpassed only by Jupiter, Venus, the Moon, optical ground-based telescopes are typically limited to resolving features about 300 kilometers across when Earth and Mars are closest because of Earths atmosphere. Mars is approximately half the diameter of Earth with an area only slightly less than the total area of Earths dry land. Mars is less dense than Earth, having about 15% of Earths volume and 11% of Earths mass, the red-orange appearance of the Martian surface is caused by iron oxide, or rust. It can look like butterscotch, other common colors include golden, brown, tan. Like Earth, Mars has differentiated into a metallic core overlaid by less dense materials. Current models of its interior imply a core with a radius of about 1,794 ±65 kilometers, consisting primarily of iron and this iron sulfide core is thought to be twice as rich in lighter elements than Earths. The core is surrounded by a mantle that formed many of the tectonic and volcanic features on the planet
20.
Human
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Modern humans are the only extant members of Hominina tribe, a branch of the tribe Hominini belonging to the family of great apes. Several of these hominins used fire, occupied much of Eurasia and they began to exhibit evidence of behavioral modernity around 50,000 years ago. In several waves of migration, anatomically modern humans ventured out of Africa, the spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide. Humans are uniquely adept at utilizing systems of communication for self-expression and the exchange of ideas. Humans create complex structures composed of many cooperating and competing groups, from families. Social interactions between humans have established a wide variety of values, social norms, and rituals. These human societies subsequently expanded in size, establishing various forms of government, religion, today the global human population is estimated by the United Nations to be near 7.5 billion. In common usage, the word generally refers to the only extant species of the genus Homo—anatomically and behaviorally modern Homo sapiens. In scientific terms, the meanings of hominid and hominin have changed during the recent decades with advances in the discovery, there is also a distinction between anatomically modern humans and Archaic Homo sapiens, the earliest fossil members of the species. The English adjective human is a Middle English loanword from Old French humain, ultimately from Latin hūmānus, the words use as a noun dates to the 16th century. The native English term man can refer to the species generally, the species binomial Homo sapiens was coined by Carl Linnaeus in his 18th century work Systema Naturae. The generic name Homo is a learned 18th century derivation from Latin homō man, the species-name sapiens means wise or sapient. Note that the Latin word homo refers to humans of either gender, the genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids branch of the primates. The closest living relatives of humans are chimpanzees and gorillas, with the sequencing of both the human and chimpanzee genome, current estimates of similarity between human and chimpanzee DNA sequences range between 95% and 99%. The gibbons and orangutans were the first groups to split from the leading to the humans. The splitting date between human and chimpanzee lineages is placed around 4–8 million years ago during the late Miocene epoch, during this split, chromosome 2 was formed from two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. There is little evidence for the divergence of the gorilla, chimpanzee. Each of these species has been argued to be an ancestor of later hominins
21.
Spectral sensitivity
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Spectral sensitivity is the relative efficiency of detection, of light or other signal, as a function of the frequency or wavelength of the signal. In visual neuroscience, spectral sensitivity is used to describe the different characteristics of the photopigments in the rod cells and cone cells in the retina of the eye. It is known that the rod cells are more suited to scotopic vision and cone cells to photopic vision, and that they differ in their sensitivity to different wavelengths of light. It has been established that the spectral sensitivity of the human eye under daylight conditions is at a wavelength of 555 nm. In photography, film and sensors are often described in terms of their spectral sensitivity, a database of camera spectral sensitivity is created and its space analyzed. For X-ray films, the sensitivity is chosen to be appropriate to the phosphors that respond to X-rays. In sensor systems, where the output is easily quantified, the responsivity can be extended to be wavelength dependent, when the sensor system is linear, its spectral sensitivity and spectral responsivity can both be decomposed with similar basis functions. In some linear applications, the spectral sensitivity may be expressed as a spectral responsivity and it is interesting to contrast the sensitivity of the eye to that of digital camera. The spectral sensitivities of CCD arrays in digital cameras are much narrower for the red, green and this processing is part of what creates the delay between the shutter snap and displaying the picture
22.
Camera
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Thumb|A2016 Nikon D810 A camera is an optical instrument for recording or capturing images, which may be stored locally, transmitted to another location, or both. The images may be individual still photographs or sequences of images constituting videos or movies, the camera is a remote sensing device as it senses subjects without physical contact. The word camera comes from camera obscura, which means dark chamber and is the Latin name of the device for projecting an image of external reality onto a flat surface. The modern photographic camera evolved from the camera obscura, the functioning of the camera is very similar to the functioning of the human eye. A camera may work with the light of the spectrum or with other portions of the electromagnetic spectrum. A still camera is a device which creates a single image of an object or scene. All cameras use the basic design, light enters an enclosed box through a converging lens/convex lens. A shutter mechanism controls the length of time that light can enter the camera, a display, often a liquid crystal display, permits the user to view scene to be recorded and settings such as ISO speed, exposure, and shutter speed. A movie camera or a video camera operates similarly to a camera, except it records a series of static images in rapid succession. When the images are combined and displayed in order, the illusion of motion is achieved, the forerunner to the photographic camera was the camera obscura. The oldest known record of this principle is a description by Han Chinese philosopher Mozi, Mozi correctly asserted that the camera obscura image is inverted because light travels in straight lines from its source. In the 11th century Arab physicist Ibn al-Haytham s wrote very influential essays about experiments with light through an opening in a darkened room. The use of a lens in the opening of a wall or closed window shutter of a room to project images used as a drawing aid has been traced back to circa 1550. Since the late 17th century portable camera obscura devices in tents, before the development of the photographic camera, it had been known for hundreds of years that some substances, such as silver salts, darkened when exposed to sunlight. The first person to use this chemistry to create images was Thomas Wedgwood, to create images, Wedgwood placed items, such as leaves and insect wings, on ceramic pots coated with silver nitrate, and exposed the set-up to light. These images werent permanent, however, as Wedgwood didnt employ a fixing mechanism and he ultimately failed at his goal of using the process to create fixed images created by a camera obscura. The first permanent photograph of an image was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles. Niépce had been experimenting with ways to fix the images of a camera obscura since 1816, the photograph Niépce succeeded in creating shows the view from his window
23.
Printer (computing)
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In computing, a printer is a peripheral which makes a persistent human-readable representation of graphics or text on paper or similar physical media. The worlds first computer printer was a 19th-century mechanically driven apparatus invented by Charles Babbage for his difference engine, the plotter was used for those requiring high quality line art like blueprints. Laser printers using PostScript mixed text and graphics, like dot-matrix printers, by 1990, most simple printing tasks like fliers and brochures were now created on personal computers and then laser printed, expensive offset printing systems were being dumped as scrap. The HP Deskjet of 1988 offered the same advantages as laser printer in terms of flexibility, inkjet systems rapidly displaced dot matrix and daisy wheel printers from the market. By the 2000s high-quality printers of this sort had fallen under the price point. Even the desire for printed output for offline reading while on mass transit or aircraft has been displaced by e-book readers, today, traditional printers are being used more for special purposes, like printing photographs or artwork, and are no longer a must-have peripheral. Starting around 2010, 3D printing became an area of intense interest and these devices are in their earliest stages of development and have not yet become commonplace. Personal printers are designed to support individual users, and may be connected to only a single computer. These printers are designed for low-volume, short-turnaround print jobs, requiring minimal setup time to produce a copy of a given document. However, they are generally slow devices ranging from 6 to around 25 pages per minute, however, this is offset by the on-demand convenience. Some printers can print documents stored on cards or from digital cameras. Networked or shared printers are designed for high-volume, high-speed printing and they are usually shared by many users on a network and can print at speeds of 45 to around 100 ppm. The Xerox 9700 could achieve 120 ppm, a virtual printer is a piece of computer software whose user interface and API resembles that of a printer driver, but which is not connected with a physical computer printer. It is called a printer by analogy with a printer which produces a two-dimensional document by a similar process of depositing a layer of ink on paper. The choice of print technology has an effect on the cost of the printer and cost of operation, speed, quality and permanence of documents. Some printer technologies dont work with certain types of physical media, cheques can be printed with liquid ink or on special cheque paper with toner anchorage so that alterations may be detected. The machine-readable lower portion of a cheque must be printed using MICR toner or ink, banks and other clearing houses employ automation equipment that relies on the magnetic flux from these specially printed characters to function properly. The following printing technologies are found in modern printers, A laser printer rapidly produces high quality text
24.
Computer monitor
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A computer monitor or a computer display is an electronic visual display for computers. A monitor usually comprises the display device, circuitry, casing, the display device in modern monitors is typically a thin film transistor liquid crystal display or a flat panel LED display, while older monitors used a cathode ray tubes. It can be connected to the computer via VGA, DVI, HDMI, DisplayPort, Thunderbolt, LVDS or other proprietary connectors, originally, computer monitors were used for data processing while television receivers were used for entertainment. From the 1980s onwards, computers have used for both data processing and entertainment, while televisions have implemented some computer functionality. The common aspect ratio of televisions, and computer monitors, has changed from 4,3 to 16,10, to 16,9. Early electronic computers were fitted with a panel of light bulbs where the state of each particular bulb would indicate the state of a particular register bit inside the computer. This allowed the operating the computer to monitor the internal state of the machine. As early monitors were only capable of displaying a limited amount of information. Instead, a printer was the primary output device, while the monitor was limited to keeping track of the programs operation. Multiple technologies have used for computer monitors. Until the 21st century most used cathode ray tubes but they have largely superseded by LCD monitors. The first computer monitors used cathode ray tubes, high-resolution CRT displays were developed for specialized military, industrial and scientific applications but they were far too costly for general use. Either computer could be connected to the terminals of an ordinary color TV set or used with a purpose-made CRT color monitor for optimum resolution. In 1984 IBM introduced the Enhanced Graphics Adapter which was capable of producing 16 colors and had a resolution of 640 x 350, by the end of the 1980s color CRT monitors that could clearly display 1024 x 768 pixels were widely available and increasingly affordable. During the following decade maximum display resolutions gradually increased and prices continued to fall, CRT technology remained dominant in the PC monitor market into the new millennium partly because it was cheaper to produce and offered viewing angles close to 180 degrees. CRTs still offer some image quality advantages over LCDs but improvements to the latter have made much less obvious. There are multiple technologies that have used to implement liquid crystal displays. Commonly, the laptop would be offered with an assortment of display options at increasing price points, monochrome
25.
ICC profile
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In color management, an ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards promulgated by the International Color Consortium. Profiles describe the attributes of a particular device or viewing requirement by defining a mapping between the device source or target color space and a profile connection space. This PCS is either CIELAB or CIEXYZ, mappings may be specified using tables, to which interpolation is applied, or through a series of parameters for transformations. Every device that captures or displays color can be profiled, the ICC defines the format precisely but does not define algorithms or processing details. This means there is room for variation between different applications and systems that work with ICC profiles, since late 2010, the current version of the specification is 4.3. Details are at http, //www. color. org/iccmax/ To see how this works in practice, suppose we have a particular RGB and CMYK color space, the first step is to obtain the two ICC profiles concerned. To perform the conversion, each RGB triplet is first converted to the Profile connection space using the RGB profile, if necessary the PCS is converted between CIELAB and CIEXYZ, a well defined transformation. Then the PCS is converted to the four values of C, M, Y, K required using the second profile, so a profile is essentially a mapping from a color space to the PCS, and from the PCS to the color space. The profile might do this using tables of values to be interpolated. A profile might define several mappings, according to rendering intent and these mappings allow a choice between closest possible color matching, and remapping the entire color range to allow for different gamuts. The reference illuminant of the Profile connection space is a 16-bit fractional approximation of D50, different source/destination white points are adapted using the Bradford transformation. Another kind of profile is the device link profile, instead of mapping between a device color space and a PCS, it maps between two specific device spaces. While this is less flexible, it allows for an accurate or purposeful conversion of color between devices. For example, a conversion between two CMYK devices could ensure that colors using only black ink convert to target colors using only black ink, the ICC profile specification, currently being progressed as International Standard ISO 15076-1,2005, is widely referred to in other standards. The following International and de facto standards are known to reference to ICC profiles. A test page for browsers ICC profiles in Adobe Photoshop CoCa - Open source ICC profile creator by Andrew Stawowczyk Long ICC profiles in MATLAB
26.
Panorama
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A panorama is any wide-angle view or representation of a physical space, whether in painting, drawing, photography, film, seismic images or a three-dimensional model. The word was coined in the 18th century by the English painter Robert Barker to describe his panoramic paintings of Edinburgh. The motion-picture term panning is derived from panorama, a panoramic view is also purposed for multi-media, cross-scale applications to an outline overview along and across repositories. This so-called cognitive panorama is a view over, and a combination of. The device of the panorama existed in painting, particularly in murals, as early as 20 A. D. in those found in Pompeii, cartographic experiments during the Enlightenment era preceded European panorama painting and contributed to a formative impulse toward panoramic vision and depiction. In the mid-19th century, panoramic paintings and models became a popular way to represent landscapes, topographic views. Audiences of Europe in this period were thrilled by the aspect of illusion, immersed in a winding 360 degree panorama, the panorama was a 360-degree visual medium patented under the title Apparatus for Exhibiting Pictures by the artist Robert Barker in 1787. The earliest that the word appeared in print was on June 11,1791 in the British newspaper The Morning Chronicle. The inaugural exhibition, a View of Edinburgh, was first shown in that city in 1788, by 1793, Barker had built The Panorama rotunda at the center of Londons entertainment district in Leicester Square, where it remained until closed in 1863. Large scale installations enhance the illusion for an audience of being surrounded with a real landscape, the Bourbaki Panorama in Lucerne, Switzerland was created by Edouard Castres in 1881. The painting measures about 10 metres in height with a circumference of 112 meters, in the United States of America is the Atlanta Cyclorama, depicting the Civil War Battle of Atlanta. It was first displayed in 1887, and is 42 feet high by 358 feet circumference, also on a gigantic scale, and still extant, is the Racławice Panorama located in Wrocław, Poland, which measures 15 x 120 metres. In addition to historical examples, there have been panoramas painted and installed in modern times, prominent among these is the Velaslavasay Panorama in Los Angeles. Panoramic photography soon came to painting as the most common method for creating wide views. Not long after the introduction of the Daguerreotype in 1839, photographers began assembling multiple images of a view into a wide image. Pinhole cameras of a variety of constructions can be used to make panoramic images and this generates an egg-shaped image with more than 180° view. They could run autonomously with silent synchronization pulses to control projector advance and fades, precisely overlapping slides placed in slide mounts with soft-edge density masks would merge seamlessly on the screen to create the panorama. Cutting and dissolving between sequential images generated animation effects in the panorama format, digital photography of the late twentieth century greatly simplified this assembly process, which is now known as image stitching
27.
Opportunity (rover)
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Opportunity, also known as MER-B or MER-1, is a robotic rover active on Mars since 2004. Opportunity has continued to move, gather scientific observations, and report back to Earth for over 50 times its designed lifespan, as of January 17,2017, the rover had traveled 43.79 kilometres. This date was mission time of Sol 4615, mission highlights include the initial 90 sol mission, finding extramartian meteorites such as Heat Shield Rock, and over two years studying Victoria crater. It survived dust-storms and reached Endeavour crater in 2011, which has described as a second landing site. C. The scientific objectives of the Mars Exploration Rover mission are to, Search for and characterize a variety of rocks, in particular, samples sought will include those that have minerals deposited by water-related processes such as precipitation, evaporation, sedimentary cementation or hydrothermal activity. Determine the distribution and composition of minerals, rocks, and soils surrounding the landing sites, determine what geologic processes have shaped the local terrain and influenced the chemistry. Such processes could include water or wind erosion, sedimentation, hydrothermal mechanisms, volcanism, perform calibration and validation of surface observations made by Mars Reconnaissance Orbiter instruments. This will help determine the accuracy and effectiveness of various instruments that survey Martian geology from orbit, Search for iron-containing minerals, identify and quantify relative amounts of specific mineral types that contain water or were formed in water, such as iron-bearing carbonates. Characterize the mineralogy and textures of rocks and soils and determine the processes that created them, Search for geological clues to the environmental conditions that existed when liquid water was present. Assess whether those environments were conducive to life, during the next two decades, NASA will continue to conduct missions to address whether life ever arose on Mars. The search begins with determining whether the Martian environment was ever suitable for life, life, as we understand it, requires water, so the history of water on Mars is critical to finding out if the Martian environment was ever conducive to life. Although the Mars Exploration Rovers do not have the ability to detect life directly, the primary surface mission for Opportunity was planned to last 90 sols. The mission has received several extensions and has been operating for 4821 days since landing, an archive of weekly updates on the rovers status can be found at the Opportunity Update Archive. Its sampling allowed NASA scientists to make hypotheses concerning the presence of hematite, following this, it was directed to travel across the surface of Mars to investigate another crater site, Endurance crater, which it investigated from June – December 2004. Subsequently, Opportunity examined the site of its own heat shield and discovered an intact meteorite, now known as Heat Shield Rock. From late April 2005 to early June of that year, Opportunity was perilously lodged in a sand dune, over a six-week period Earth-based physical simulations were performed to decide how best to extract the rover from its position without risking a permanent immobilization of the valuable vehicle. Successful maneuvering a few centimeters at a time eventually freed the rover and it experienced some mechanical problems with its robotic arm. In late September 2006, Opportunity reached Victoria crater and explored along the rim in a clockwise direction, in June 2007 it returned to Duck Bay, its original arrival point, in September 2007 it entered the crater to begin a detailed study
28.
Electromagnetic radiation
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In physics, electromagnetic radiation refers to the waves of the electromagnetic field, propagating through space carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, light, ultraviolet, X-, classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum. The oscillations of the two fields are perpendicular to other and perpendicular to the direction of energy and wave propagation. The wavefront of electromagnetic waves emitted from a point source is a sphere, the position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves are produced whenever charged particles are accelerated, and these waves can interact with other charged particles. EM waves carry energy, momentum and angular momentum away from their source particle, quanta of EM waves are called photons, whose rest mass is zero, but whose energy, or equivalent total mass, is not zero so they are still affected by gravity. Thus, EMR is sometimes referred to as the far field, in this language, the near field refers to EM fields near the charges and current that directly produced them, specifically, electromagnetic induction and electrostatic induction phenomena. In the quantum theory of electromagnetism, EMR consists of photons, quantum effects provide additional sources of EMR, such as the transition of electrons to lower energy levels in an atom and black-body radiation. The energy of a photon is quantized and is greater for photons of higher frequency. This relationship is given by Plancks equation E = hν, where E is the energy per photon, ν is the frequency of the photon, a single gamma ray photon, for example, might carry ~100,000 times the energy of a single photon of visible light. The effects of EMR upon chemical compounds and biological organisms depend both upon the power and its frequency. EMR of visible or lower frequencies is called non-ionizing radiation, because its photons do not individually have enough energy to ionize atoms or molecules, the effects of these radiations on chemical systems and living tissue are caused primarily by heating effects from the combined energy transfer of many photons. In contrast, high ultraviolet, X-rays and gamma rays are called ionizing radiation since individual photons of high frequency have enough energy to ionize molecules or break chemical bonds. These radiations have the ability to cause chemical reactions and damage living cells beyond that resulting from simple heating, Maxwell derived a wave form of the electric and magnetic equations, thus uncovering the wave-like nature of electric and magnetic fields and their symmetry. Because the speed of EM waves predicted by the wave equation coincided with the speed of light. Maxwell’s equations were confirmed by Heinrich Hertz through experiments with radio waves, according to Maxwells equations, a spatially varying electric field is always associated with a magnetic field that changes over time. Likewise, a varying magnetic field is associated with specific changes over time in the electric field. In an electromagnetic wave, the changes in the field are always accompanied by a wave in the magnetic field in one direction
29.
Ultraviolet
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Ultraviolet is an electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV radiation constitutes about 10% of the light output of the Sun. It is also produced by electric arcs and specialized lights, such as lamps, tanning lamps. Consequently, the effects of UV are greater than simple heating effects. Suntan, freckling and sunburn are familiar effects of over-exposure, along with risk of skin cancer. Living things on dry land would be damaged by ultraviolet radiation from the Sun if most of it were not filtered out by the Earths atmosphere. More-energetic, shorter-wavelength extreme UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground, Ultraviolet is also responsible for the formation of bone-strengthening vitamin D in most land vertebrates, including humans. The UV spectrum thus has both beneficial and harmful to human health. Ultraviolet rays are invisible to most humans, the lens in a human eye ordinarily filters out UVB frequencies or higher, and humans lack color receptor adaptations for ultraviolet rays. Under some conditions, children and young adults can see ultraviolet down to wavelengths of about 310 nm, near-UV radiation is visible to some insects, mammals, and birds. Small birds have a fourth color receptor for ultraviolet rays, this gives birds true UV vision, reindeer use near-UV radiation to see polar bears, who are poorly visible in regular light because they blend in with the snow. UV also allows mammals to see urine trails, which is helpful for animals to find food in the wild. The males and females of some species look identical to the human eye. Ultraviolet means beyond violet, violet being the color of the highest frequencies of visible light, Ultraviolet has a higher frequency than violet light. He called them oxidizing rays to emphasize chemical reactivity and to them from heat rays. The terms chemical and heat rays were eventually dropped in favour of ultraviolet and infrared radiation, in 1878 the effect of short-wavelength light on sterilizing bacteria was discovered. By 1903 it was known the most effective wavelengths were around 250 nm, in 1960, the effect of ultraviolet radiation on DNA was established. The discovery of the ultraviolet radiation below 200 nm, named vacuum ultraviolet because it is absorbed by air, was made in 1893 by the German physicist Victor Schumann
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X-ray
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X-radiation is a form of electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz, X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. Spelling of X-ray in the English language includes the variants x-ray, xray, X-rays with high photon energies are called hard X-rays, while those with lower energy are called soft X-rays. Due to their ability, hard X-rays are widely used to image the inside of objects, e. g. in medical radiography. The term X-ray is metonymically used to refer to an image produced using this method. Since the wavelengths of hard X-rays are similar to the size of atoms they are useful for determining crystal structures by X-ray crystallography. By contrast, soft X-rays are easily absorbed in air, the length of 600 eV X-rays in water is less than 1 micrometer. There is no consensus for a definition distinguishing between X-rays and gamma rays, one common practice is to distinguish between the two types of radiation based on their source, X-rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus. This definition has problems, other processes also can generate these high-energy photons. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m and this criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. Occasionally, one term or the other is used in specific contexts due to precedent, based on measurement technique. Thus, gamma-rays generated for medical and industrial uses, for radiotherapy, in the ranges of 6–20 MeV. X-ray photons carry enough energy to ionize atoms and disrupt molecular bonds and this makes it a type of ionizing radiation, and therefore harmful to living tissue. A very high radiation dose over a period of time causes radiation sickness. In medical imaging this increased risk is generally greatly outweighed by the benefits of the examination. The ionizing capability of X-rays can be utilized in treatment to kill malignant cells using radiation therapy. It is also used for material characterization using X-ray spectroscopy, hard X-rays can traverse relatively thick objects without being much absorbed or scattered. For this reason, X-rays are widely used to image the inside of visually opaque objects, the most often seen applications are in medical radiography and airport security scanners, but similar techniques are also important in industry and research
31.
Trichromacy
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Trichromacy or trichromaticism is the possessing of three independent channels for conveying color information, derived from the three different types of cone cells in the eye. Organisms with trichromacy are called trichromats, the normal explanation of trichromacy is that the organisms retina contains three types of color receptors with different absorption spectra. In actuality the number of such receptor types may be greater than three, since different types may be active at different light intensities, in vertebrates with three types of cone cells, at low light intensities the rod cells may contribute to color vision. Humans and some mammals have evolved trichromacy based partly on pigments inherited from early vertebrates. In fish and birds, for example, four pigments are used for vision and these extra cone receptor visual pigments detect energy of other wavelengths, including sometimes ultraviolet. Eventually two of these pigments were lost and another was gained, resulting in trichromacy among some primates, humans and closely related primates are usually trichromats, as are some of the females of most species of New World monkeys, and both male and female howler monkeys. Recent research suggests that trichromacy may also be quite general among marsupials, the possibility of trichromacy in marsupials potentially has another evolutionary basis than that of primates. Further biological and behavioural tests may verify if trichromacy is a characteristic of marsupials. Most other mammals are thought to be dichromats, with only two types of cone. Most studies of carnivores, as of mammals, reveal dichromacy, examples including the domestic dog, the ferret. Some species of insects are also trichromats, being sensitive to ultraviolet, blue and green instead of blue, green, research indicates that trichromacy allows animals to distinguish red fruit and young leaves from other vegetation that is not beneficial to their survival. Another theory is that detecting skin flushing and thereby mood may have influenced the development of primate trichromate vision, the color red also has other effects on primate and human behavior as discussed in the color psychology article. Primates are the only known placental mammalian trichromats and their eyes include three different kinds of cones, each containing a different photopigment. Their peak sensitivities lie in the blue, green and yellow-green regions of the color spectrum, S cones make up 5–10% of the cones and form a regular mosaic. Special bipolar and ganglion cells pass those signals from S cones, but Mollon and Bowmaker did find that L cones and M cones are randomly distributed and are in equal numbers. Trichromatic color vision is the ability of humans and some animals to see different colors. The trichromatic color theory began in the 18th century, when Thomas Young proposed that vision was a result of three different photoreceptor cells. Hermann von Helmholtz later expanded on Youngs ideas using color-matching experiments which showed that people with normal vision needed three wavelengths to create the normal range of colors, physiological evidence for trichromatic theory was later given by Gunnar Svaetichin
32.
Earth
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Earth, otherwise known as the World, or the Globe, is the third planet from the Sun and the only object in the Universe known to harbor life. It is the densest planet in the Solar System and the largest of the four terrestrial planets, according to radiometric dating and other sources of evidence, Earth formed about 4.54 billion years ago. Earths gravity interacts with objects in space, especially the Sun. During one orbit around the Sun, Earth rotates about its axis over 365 times, thus, Earths axis of rotation is tilted, producing seasonal variations on the planets surface. The gravitational interaction between the Earth and Moon causes ocean tides, stabilizes the Earths orientation on its axis, Earths lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earths surface is covered with water, mostly by its oceans, the remaining 29% is land consisting of continents and islands that together have many lakes, rivers and other sources of water that contribute to the hydrosphere. The majority of Earths polar regions are covered in ice, including the Antarctic ice sheet, Earths interior remains active with a solid iron inner core, a liquid outer core that generates the Earths magnetic field, and a convecting mantle that drives plate tectonics. Within the first billion years of Earths history, life appeared in the oceans and began to affect the Earths atmosphere and surface, some geological evidence indicates that life may have arisen as much as 4.1 billion years ago. Since then, the combination of Earths distance from the Sun, physical properties, in the history of the Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinction events. Over 99% of all species that lived on Earth are extinct. Estimates of the number of species on Earth today vary widely, over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival. Humans have developed diverse societies and cultures, politically, the world has about 200 sovereign states, the modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most often spelled eorðe. It has cognates in every Germanic language, and their proto-Germanic root has been reconstructed as *erþō, originally, earth was written in lowercase, and from early Middle English, its definite sense as the globe was expressed as the earth. By early Modern English, many nouns were capitalized, and the became the Earth. More recently, the name is simply given as Earth. House styles now vary, Oxford spelling recognizes the lowercase form as the most common, another convention capitalizes Earth when appearing as a name but writes it in lowercase when preceded by the. It almost always appears in lowercase in colloquial expressions such as what on earth are you doing, the oldest material found in the Solar System is dated to 4. 5672±0.0006 billion years ago. By 4. 54±0.04 Gya the primordial Earth had formed, the formation and evolution of Solar System bodies occurred along with the Sun
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Remote sensing
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Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation. It may be split into active remote sensing and passive 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 the hand, emits energy in order to scan objects and areas whereupon a sensor then detects. RADAR and LiDAR are examples of 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 data of dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as the Amazon Basin, glacial features in Arctic and Antarctic regions, 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, the basis for multispectral collection and analysis 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, conventional radar is mostly associated with aerial traffic control, early warning, and certain large scale meteorological data. Other types of active collection includes plasmas in the ionosphere, interferometric synthetic aperture radar is used to produce precise digital elevation models of large scale terrain. Laser and radar altimeters on satellites have provided a range of data. By measuring the bulges of water caused by gravity, they map features on the seafloor to a resolution of a mile or so, by measuring the height and wavelength of ocean waves, the altimeters measure wind speeds and direction, and surface ocean currents and directions. Ultrasound and radar tide gauges measure sea level, tides and wave direction in coastal, light detection and ranging is well known in examples of weapon ranging, laser illuminated homing of projectiles. Vegetation remote sensing is an application of LIDAR. Radiometers and photometers are the most common instrument in use, collecting reflected and emitted radiation in a range of frequencies. The most common are visible and infrared sensors, followed by microwave, gamma ray and rarely and they may also be used to detect the emission spectra of various chemicals, providing data on chemical concentrations in the atmosphere. Simultaneous multi-spectral platforms such as Landsat have been in use since the 1970s and these thematic mappers take images in multiple wavelengths of electro-magnetic radiation and are usually found on Earth observation satellites, including the Landsat program or the IKONOS satellite. Landsat images are used by agencies such as KYDOW to indicate water quality parameters including Secchi depth, chlorophyll a density
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Space telescope
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A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects. Space telescopes avoid many of the problems of ground-based observatories, such as pollution and distortion of electromagnetic radiation. In addition, ultraviolet frequencies, X-rays and gamma rays are blocked by the Earths atmosphere, Space telescopes are distinct from other imaging satellites pointed toward Earth for purposes of espionage, weather analysis and other types of information gathering. Spitzers proposal called for a telescope that would not be hindered by Earths atmosphere. Performing astronomy from ground-based observatories on Earth is limited by the filtering, some terrestrial telescopes can reduce atmospheric effects with adaptive optics. A telescope orbiting Earth outside the atmosphere is subject neither to twinkling nor to light pollution from artificial light sources on Earth, as a result, the angular resolution of space telescopes is often much smaller than a ground-based telescope with a similar aperture. Infrared and ultraviolet are also largely blocked, however, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes, due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all, Space observatories can generally be divided into two classes, missions which map the entire sky, and observatories which focus on selected astronomical objects or parts of the sky. Many space observatories have already completed their missions, while others continue operating, satellites have been launched and operated by NASA, ISRO, ESA, Japanese Space Agency and the Soviet space program later succeeded by Roskosmos of Russia. Many space telescopes have been launched, as of February 2017, over 20 telescopes are known to be operational
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Hubble Space Telescope
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The Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. Although not the first space telescope, Hubble is one of the largest and most versatile, with a 2. 4-meter mirror, Hubbles four main instruments observe in the near ultraviolet, visible, and near infrared spectra. Hubbles orbit outside the distortion of Earths atmosphere allows it to take extremely high-resolution images, Hubble has recorded some of the most detailed visible light images ever, allowing a deep view into space and time. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe. The HST was built by the United States space agency NASA, the Space Telescope Science Institute selects Hubbles targets and processes the resulting data, while the Goddard Space Flight Center controls the spacecraft. Space telescopes were proposed as early as 1923, Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster. When finally launched in 1990, Hubbles main mirror was found to have been ground incorrectly, the optics were corrected to their intended quality by a servicing mission in 1993. Hubble is the telescope designed to be serviced in space by astronauts. After launch by Space Shuttle Discovery in 1990, five subsequent Space Shuttle missions repaired, upgraded, the fifth mission was canceled on safety grounds following the Columbia disaster. However, after spirited public discussion, NASA administrator Mike Griffin approved the fifth servicing mission, the telescope is operating as of 2017, and could last until 2030–2040. Its scientific successor, the James Webb Space Telescope, is scheduled for launch in 2018, the history of the Hubble Space Telescope can be traced back as far as 1946, to the astronomer Lyman Spitzers paper Astronomical advantages of an extraterrestrial observatory. In it, he discussed the two advantages that a space-based observatory would have over ground-based telescopes. First, the resolution would be limited only by diffraction, rather than by the turbulence in the atmosphere. Second, a telescope could observe infrared and ultraviolet light. Spitzer devoted much of his career to pushing for the development of a space telescope, space-based astronomy had begun on a very small scale following World War II, as scientists made use of developments that had taken place in rocket technology. An orbiting solar telescope was launched in 1962 by the United Kingdom as part of the Ariel space program, oAO-1s battery failed after three days, terminating the mission. It was followed by OAO-2, which carried out observations of stars and galaxies from its launch in 1968 until 1972. The continuing success of the OAO program encouraged increasingly strong consensus within the community that the LST should be a major goal
36.
Space probe
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A space probe is a robotic spacecraft that does not orbit the Earth, but, instead, explores further into outer space. A space probe may approach the Moon, travel through space, flyby, orbit, or land on other planetary bodies. Approximately fifteen missions are currently operational, once a probe has left the vicinity of Earth, its trajectory will likely take it along an orbit around the Sun similar to the Earths orbit. To reach another planet, the simplest practical method is a Hohmann transfer orbit, more complex techniques, such as gravitational slingshots, can be more fuel-efficient, though they may require the probe to spend more time in transit. Some high Delta-V missions can only be performed, within the limits of modern propulsion, a technique using very little propulsion, but requiring a considerable amount of time, is to follow a trajectory on the Interplanetary Transport Network. First man-made object to land on the Moon, or any other extra terrestrial surface. First mission to photograph the far side of the Moon, launched in 1959, first robotic sample return probe from the Moon. It was sent to the Moon on November 10,1970, first successful in-place analysis of another planet. It may have also been the first space probe to impact the surface of another planet, the Venera 7 probe was the first spacecraft to successfully soft land on another planet and to transmit data from there back to Earth. Upon its arrival at Mars on November 13,1971, Mariner 9 became the first space probe to orbit around another planet. Although, the spacecraft failed shortly after landing, the Mars Exploration Rovers, Spirit and Opportunity surface and geology, and searched for clues to past water activity on Mars. They were each launched in 2003 and landed in 2004, communication with Spirit stopped on sol 2210. JPL continued to attempt to regain contact until May 24,2011, Opportunity arrived at Endeavour crater on 9 August 2011, at a landmark called Spirit Point named after its rover twin, after traversing 13 miles from Victoria crater, over a three-year period. As of January 26,2016, Opportunity has lasted for more than twelve years on Mars — although the rovers were intended to last only three months. The first dedicated missions to a comet, in this case and they dropped landers and balloons at Venus before their rendezvous with Halleys Comet. This Japanese probe was the first non-US, non-Soviet interplanetary probe, a second Japanese probe, it made ultraviolet wavelength observations of the comet. The first space probe to penetrate a comets coma and take images of its nucleus. First solar wind sample return probe from sun-earth L1, first sample return probe from a comet tail
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Rover (space exploration)
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A rover is a space exploration vehicle designed to move across the surface of a planet or other celestial body. Some rovers have been designed to transport members of a human spaceflight crew, Rovers usually arrive at the planetary surface on a lander-style spacecraft. Rovers are created to land on another planet, besides Earth, to find out information and they can collect dust, rocks, and even take pictures. Rovers have several advantages over stationary landers, they examine more territory, if they are solar powered, they can place themselves in sunny positions to weather winter months. They can also advance the knowledge of how to perform very remote robotic vehicle control which is necessarily semi-autonomous due to the speed of light. Their advantages over orbiting spacecraft are that they can make observations to a microscopic level, Rovers arrive on spacecraft and are used in conditions very distinct from those on the Earth, which makes some demands on their design. Rovers have to high levels of acceleration, high and low temperatures, pressure, dust, corrosion, cosmic rays. Rovers are usually packed for placing in a spacecraft, because it has limited capacity and they are also attached to a spacecraft, so devices for removing these connections are installed. For example, sending a signal from Mars to Earth takes between 3 and 21 minutes, giving a rover some rudimentary visual identification capabilities to make simple distinctions can allow engineers to speed up the reconnaissance. Other rover designs that do not use wheeled approaches are possible, mechanisms that utilize walking on robotic legs, hopping, rolling, etc. are possible. The Soviet rover was intended to be the first roving remote-controlled robot on the Moon, the Lunokhod 1 rover landed on the Moon in November 1970. It was the first roving remote-controlled robot to land on any celestial body, the Soviet Union launched Lunokhod 1 aboard the Luna 17 spacecraft on November 10,1970, and it entered lunar orbit on November 15. The spacecraft soft-landed in the Sea of Rains region on November 17, the lander had dual ramps from which Lunokhod 1 could descend to the lunar surface, which it did at 06,28 UT. From November 17,1970 to November 22,1970 the rover drove 197 m and it also analyzed the lunar soil. The last successful communications session with Lunokhod 1 was on September 14,1971, having worked for 11 months, Lunokhod 1 held the durability record for space rovers for more than 30 years, until a new record was set by the Mars Exploration Rovers. NASA included Lunar Roving Vehicles in three Apollo missions, Apollo 15, Apollo 16 and Apollo 17, the Lunokhod 2 was the second of two unmanned lunar rovers landed on the Moon by the Soviet Union as part of the Lunokhod program. The rover became operational on the Moon on January 16,1973 and it was the second roving remote-controlled robot to land on any celestial body. The Soviet Union launched Lunokhod 2 aboard the Luna 21 spacecraft on January 8,1973, the spacecraft soft-landed in the eastern edge of the Mare Serenitatis region on January 15,1973
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Mars Science Laboratory
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Mars Science Laboratory is a robotic space probe mission to Mars launched by NASA on November 26,2011, which successfully landed Curiosity, a Mars rover, in Gale Crater on August 6,2012. The overall objectives include investigating Mars habitability, studying its climate and geology, the rover carries a variety of scientific instruments designed by an international team. MSL successfully carried out the most accurate Martian landing of any spacecraft, hitting a small target landing ellipse of only 7 by 20 km. In the event, MSL achieved a landing 2.4 km east and 400 m north of the center of the target and this location is near the mountain Aeolis Mons. The rover mission is set to explore for at least 687 Earth days over a range of 5 by 20 km, the total cost of the MSL project is about US$2.5 billion. Mars rovers include Sojourner from the Mars Pathfinder mission and the Mars Exploration Rovers Spirit, Curiosity is about twice as long and five times as heavy as Spirit and Opportunity, and carries over ten times the mass of scientific instruments. The MSL mission has four scientific goals, Determine the landing sites habitability including the role of water, the study of the climate and it is also useful preparation for a future manned mission to Mars. This data would be important for a manned mission. The MSL spacecraft includes spaceflight-specific instruments, in addition to utilizing one of the rover instruments—Radiation assessment detector —during the spaceflight transit to Mars. MSL EDL Instrument, The MEDLI projects main objective is to measure aerothermal environments, sub-surface heat shield material response, vehicle orientation, the MEDLI instrumentation suite was installed in the heatshield of the MSL entry vehicle. The acquired data will support future Mars missions by providing measured atmospheric data to validate Mars atmosphere models, MEDLI instrumentation consists of three main subsystems, MEDLI Integrated Sensor Plugs, Mars Entry Atmospheric Data System and the Sensor Support Electronics. Each computers memory includes 256 KB of EEPROM,256 MB of DRAM and this compares to 3 MB of EEPROM,128 MB of DRAM, and 256 MB of flash memory used in the Mars Exploration Rovers. The RCE computers use the RAD750 CPU operating at 200 MHz, the RAD750 CPU is capable of up to 400 MIPS, while the RAD6000 CPU is capable of up to 35 MIPS. Of the two computers, one is configured as backup, and will take over in the event of problems with the main computer. The rover has an Inertial Measurement Unit that provides 3-axis information on its position, the rovers computers are constantly self-monitoring to keep the rover operational, such as by regulating the rovers temperature. Activities such as taking pictures, driving, and operating the instruments are performed in a sequence that is sent from the flight team to the rover. The rovers computers function on VxWorks, an operating system from Wind River Systems. Once landed, the applications were replaced with software for driving on the surface, communications, Curiosity is equipped with several means of communication, for redundancy
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Weather satellite
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The weather satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting, covering the entire Earth asynchronously, or geostationary, Meteorological satellites see more than clouds and cloud systems. City lights, fires, effects of pollution, auroras, sand and dust storms, snow cover, ice mapping, boundaries of currents, energy flows. Other types of information are collected using weather satellites. Weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens, smoke from fires in the western United States such as Colorado and Utah have also been monitored. Other environmental satellites can detect changes in the Earths vegetation, sea state, ocean color, El Niño and its effects on weather are monitored daily from satellite images. The Antarctic ozone hole is mapped from weather satellite data, collectively, weather satellites flown by the U. S. Europe, India, China, Russia, and Japan provide nearly continuous observations for a global weather watch. As early as 1946, the idea of cameras in orbit to observe the weather was being developed and this was due to sparse data observation coverage and the expense of using cloud cameras on rockets. By 1958, the prototypes for TIROS and Vanguard were created. The first weather satellite, Vanguard 2, was launched on February 17,1959 and it was designed to measure cloud cover and resistance, but a poor axis of rotation and its elliptical orbit kept it from collecting a notable amount of useful data. The Explorer VI and VII satellites also contained weather-related experiments, the first weather satellite to be considered a success was TIROS-1, launched by NASA on April 1,1960. TIROS operated for 78 days and proved to be more successful than Vanguard 2. TIROS paved the way for the Nimbus program, whose technology and findings are the heritage of most of the Earth-observing satellites NASA, the ESSA and NOAA polar orbiting satellites followed suit from the late 1960s onward. Geostationary satellites followed, beginning with the ATS and SMS series in the late 1960s and early 1970s, observation is typically made via different channels of the electromagnetic spectrum, in particular, the visible and infrared portions. Some of these channels include Visible and Near Infrared,0.6 μm –1.6 μm – For recording cloud cover during the day Infrared,3.9 μm –7.3 μm,8.7 μm, –13. Even wind can be determined by cloud patterns, alignments and movement from successive photos, Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea, even El Niño phenomena can be spotted. Using color-digitized techniques, the gray shaded thermal images can be converted to color for easier identification of desired information, each meteorological satellite is designed to use one of two different classes of orbit, geostationary and polar orbiting
40.
Precision agriculture
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Precision agriculture or satellite farming or site specific crop management is a farming management concept based on observing, measuring and responding to inter and intra-field variability in crops. The goal of precision agriculture research is to define a decision support system for whole farm management with the goal of optimizing returns on inputs while preserving resources, among these many approaches is a phytogeomorphological approach which ties multi-year crop growth stability/characteristics to topological terrain attributes. The interest in the phytogeomorphological approach stems from the fact that the geomorphology component typically dictates the hydrology of the farm field, the practice of precision agriculture has been enabled by the advent of GPS and GNSS. The farmers and/or researchers ability to locate their position in a field allows for the creation of maps of the spatial variability of as many variables as can be measured. This data is used by variable rate technology including seeders, sprayers. Precision agriculture has also enabled by affordable unmanned aerial vehicles like the DJI Phantom that cost under $1000. It has been described as Big Data on the farm, monsanto, DuPont and others are launching this technology in the US. Geolocation is done in two ways, The field is delineated using an in-vehicle GPS receiver as the drives a tractor around the field. The field is delineated on a derived from aerial or satellite imagery. The base images must have the level of resolution and geometric quality to ensure that geolocation is sufficiently accurate. Intra and inter-field variability may result from a number of factors and these include climatic conditions, soils, cropping practices, weeds and disease. Permanent indicators—chiefly soil indicators—provide farmers with information about the main environmental constants and this information may come from weather stations and other sensors. Soil resistivity measurements combined with soil analysis make it possible to measure moisture content, soil resistivity is also a relatively simple and cheap measurement. Using soil maps, farmers can pursue two strategies to adjust field inputs, Predictive approach, based on analysis of static indicators during the crop cycle, airborne instruments are able to measure the amount of plant cover and to distinguish between crops and weeds. Decisions may be based on models, but in the final analysis it is up to the farmer to decide in terms of business value. New information and communication technologies make field-level crop management more operational, the use of automated or robotic data gathering techniques is on the rise. ROS Agriculture - Software for agricultural robotics, the concept of precision agriculture first emerged in the United States in the early 1980s. In 1985, researchers at the University of Minnesota varied lime inputs in crop fields and it was also at this time that the practice of grid sampling appeared
41.
Messier 66
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Messier 66 is an intermediate spiral galaxy about 36 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780, M66 is about 95 thousand light-years across with striking dust lanes and bright star clusters along sweeping spiral arms. M66 is part of the Leo Triplet, a group of galaxies that also includes M65. As of 2015, four supernovae have been observed in M66, the latter feature shows up visually as an extremely prominent and unusual spiral arm and dust lane structures as originally noted in the Atlas of Peculiar Galaxies. SEDS, Spiral Galaxy M66 Spiral Galaxy M66 Astronomy Picture of the Day – Unusual Spiral Galaxy M66 from Hubble –2010 April 13 Merrifield, Mike, Szymanek, Nik. Messier 66 on WikiSky, DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
42.
Polycyclic aromatic hydrocarbon
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Polycyclic aromatic hydrocarbons are hydrocarbons—organic compounds containing only carbon and hydrogen—that are composed of multiple aromatic rings. Formally, the class is defined as lacking further branching substituents on these ring structures. Polynuclear aromatic hydrocarbons are a subset of PAHs that have fused aromatic rings, the simplest such chemicals are naphthalene, having two aromatic rings, and the three-ring compounds anthracene and phenanthrene. PAHs are neutral, nonpolar molecules found in coal and in tar deposits and they are produced as well by incomplete combustion of organic matter. The tricyclic species phenanthrene and anthracene represent the members of the PAHs. Smaller molecules, such as benzene, are not PAHs, PAHs with five or six-membered rings are most common. Those composed only of six-membered rings are called alternant PAHs, which include benzenoid PAHs, the following are examples of PAHs that vary in the number and arrangement of their rings, Examples of PAH compounds PAHs are nonpolar and lipophilic. Larger PAHs are generally insoluble in water, while some PAHs are soluble, the larger members are also poorly soluble in organic solvents as well as lipids. Although PAHs clearly are aromatic compounds, the degree of aromaticity can be different for each ring segment, according to Clars rule for PAHs the resonance structure with the largest number of disjoint aromatic п-sextets—i. e. Benzene-like moieties—is the most important for the characterization of the properties, in contrast, in anthracene the resonance structures have one sextet, which can be at any of the three rings, and the aromaticity spreads out more evenly across the whole molecule. Three Clar structures with two each are present in chrysene. Superposition of these reveals that the aromaticity in the outer rings is greater compared to the inner rings. Polycyclic aromatic hydrocarbons are found in natural sources such as creosote. They can result from the combustion of organic matter. PAHs can also be produced geologically when organic sediments are transformed into fossil fuels such as oil. Wild fires are another notable source, substantially higher outdoor air, soil, and water concentrations of PAHs have been measured in Asia, Africa, and Latin America than in Europe, Australia, and the U. S. /Canada. PAHs are typically found as complex mixtures, most PAHs are insoluble in water, which limits their mobility in the environment. Aqueous solubility of PAHs decreases approximately logarithmically as molecular mass increases, two-ring PAHs, and to a lesser extent three-ring PAHs, dissolve in water, making them more available for biological uptake and degradation
43.
Grayscale
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In photography and computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample, that is, it carries only intensity information. Images of this sort, also known as black-and-white, are composed exclusively of shades of gray, grayscale images are distinct from one-bit bi-tonal black-and-white images, which in the context of computer imaging are images with only two colors, black and white. Grayscale images have many shades of gray in between, but also they can be synthesized from a full color image, see the section about converting to grayscale. The intensity of a pixel is expressed within a range between a minimum and a maximum, inclusive. This range is represented in a way as a range from 0 and 1. This notation is used in papers, but this does not define what black or white is in terms of colorimetry. Another convention is to employ percentages, so the scale is then from 0% to 100%. This is used for an intuitive approach, but if only integer values are used, the range encompasses a total of only 101 intensities. Also, the notation is used in printing to denote how much ink is employed in halftoning. In computing, although the grayscale can be computed through rational numbers, image pixels are stored in binary, the precision provided by this format is barely sufficient to avoid visible banding artifacts, but very convenient for programming because a single pixel then occupies a single byte. Technical uses often require more levels, to full use of the sensor accuracy. Sixteen bits per sample is a convenient choice for such uses, the TIFF and the PNG image file formats support 16-bit grayscale natively, although browsers and many imaging programs tend to ignore the low order 8 bits of each pixel. No matter what pixel depth is used, the binary representations assume that 0 is black, a common strategy is to use the principles of photometry or, more broadly, colorimetry to match the luminance of the grayscale image to the luminance of the original color image. This also ensures that both images will have the absolute luminance, as can be measured in its SI units of candelas per square meter, in any given area of the image. Then, linear luminance is calculated as a sum of the three linear-intensity values. To encode grayscale intensity in linear RGB, each of the three primaries can be set to equal the calculated linear luminance Y, linear luminance typically needs to be gamma compressed to get back to a conventional non-linear representation. In practice, because the three components are then equal, it is only necessary to store these values once in sRGB-compatible image formats that support a single-channel representation. The ITU-R BT.709 standard used for HDTV developed by the ATSC uses different color coefficients, although these are numerically the same coefficients used in sRGB above, the effect is different because here they are being applied directly to gamma-compressed values
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