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Sunrise (telescope)
The Sunrise balloon-borne solar observatory consists of a 1m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system and further infrastructure. The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and magnetic fields at a resolution of around 100 km in the quiet Sun. Overview The strong absorption of UV radiation by the Earth's atmosphere makes it challenging to carry out ground-based observations at these wavelengths. A balloon mission reaching altitudes of above 30 km benefits from a reduction of UV absorption by 99%, making engineering solutions for the telescope easier. The launch site was in the arctic region to make uninterrupted observation of the Sun over several days possible. The telescope has a 1 metre primary mirror that directs the 1 kW of solar radiation to the first focal point where 99% of the radiation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balloon-borne Telescope
A balloon-borne telescope is a type of airborne telescope, a sub-orbital astronomical telescope that is suspended below one or more stratospheric balloons, allowing it to be lifted above the lower, dense part of the Earth's atmosphere. This has the advantage of improving the resolution limit of the telescope at a much lower cost than for a space telescope. It also allows observation of frequency bands that are blocked by the atmosphere. Balloon-borne telescopes have the disadvantage of relatively low altitude and a flight time of only a few days. However, their maximum altitude of about 50 km is much higher than the limiting altitude of aircraft-borne telescopes such as the Kuiper Airborne Observatory and Stratospheric Observatory for Infrared Astronomy, which have a limiting altitude of 15 km. A few balloon-borne telescopes have crash landed, resulting in damage to, or destruction of the telescope. The balloon obscures the zenith from the telescope, but a very long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic
The Arctic ( or ) is a polar regions of Earth, polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, Norway, Russia (Murmansk Oblast, Murmansk, Siberia, Nenets Autonomous Okrug, Nenets Okrug, Novaya Zemlya), Sweden and the United States (Alaska). Land within the Arctic region has seasonally varying snow and sea ice, ice cover, with predominantly treeless permafrost (permanently frozen underground ice) containing tundra. Arctic seas contain seasonal sea ice in many places. The Arctic region is a unique area among Earth's ecosystems. The cultures in the region and the Arctic indigenous peoples have adapted to its cold and extreme conditions. Life in the Arctic includes zooplankton and phytoplankton, fish and marine mammals, birds, land animals, plants and human societies. Arctic land is bordered by the subarctic. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somerset Island (Nunavut)
Somerset Island (Inuktitut ''Kuuganajuk'') is a large, uninhabited island of the Arctic Archipelago, that is part of the Canadian territory of Nunavut. The island is separated from Cornwallis Island (Nunavut), Cornwallis Island and Devon Island to the north by the Parry Channel, from Baffin Island to the east by Prince Regent Inlet, from the Boothia Peninsula to the south by Bellot Strait, and from Prince of Wales Island (Nunavut), Prince of Wales Island to the west by Peel Sound. It has an area of , making it the List of islands by area, 46th largest island in the world and List of Canadian islands by area, Canada's twelfth largest island. History Around 1000 AD, the north coast of Somerset Island was inhabited by the Thule people, as evidenced by whale bones, tunnels and stone ruins. William Edward Parry was the first documented European to sight the island in 1819. HMS Fury (1814), HMS ''Fury'' was an Arctic exploration ship commanded by Henry Parkyns Hoppner. She was damage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeeman Splitting
The Zeeman effect (; ) is the effect of splitting of a spectral line into several components in the presence of a static magnetic field. It is named after the Dutch physicist Pieter Zeeman, who discovered it in 1896 and received a Nobel prize for this discovery. It is analogous to the Stark effect, the splitting of a spectral line into several components in the presence of an electric field. Also similar to the Stark effect, transitions between different components have, in general, different intensities, with some being entirely forbidden (in the dipole approximation), as governed by the selection rules. Since the distance between the Zeeman sub-levels is a function of magnetic field strength, this effect can be used to measure magnetic field strength, e.g. that of the Sun and other stars or in laboratory plasmas. The Zeeman effect is very important in applications such as nuclear magnetic resonance spectroscopy, electron spin resonance spectroscopy, magnetic resonance imagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter (optics)
An optical filter is a device that selectively transmits light of different wavelengths, usually implemented as a glass plane or plastic device in the optical path, which are either dyed in the bulk or have interference coatings. The optical properties of filters are completely described by their frequency response, which specifies how the magnitude and phase of each frequency component of an incoming signal is modified by the filter. Filters mostly belong to one of two categories. The simplest, physically, is the absorptive filter; then there are interference or dichroic filters. Many optical filters are used for optical imaging and are manufactured to be transparent; some used for light sources can be translucent. Optical filters selectively transmit light in a particular range of wavelengths, that is, colours, while absorbing the remainder. They can usually pass long wavelengths only (longpass), short wavelengths only (shortpass), or a band of wavelengths, blocking both l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Stabilization
Image stabilization (IS) is a family of techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure. Generally, it compensates for pan and tilt (angular movement, equivalent to yaw and pitch) of the imaging device, though electronic image stabilization can also compensate for rotation. It is mainly used in high-end image-stabilized binoculars, still and video cameras, astronomical telescopes, and also smartphones. With still cameras, camera shake is a particular problem at slow shutter speeds or with long focal length lenses (telephoto or zoom). With video cameras, camera shake causes visible frame-to-frame jitter in the recorded video. In astronomy, the problem of lens shake is added to variation in the atmosphere, which changes the apparent positions of objects over time. Application in still photography In photography, image stabilization can facilitate shutter speeds 2 to 5.5 stops slower (exposures 4 to times l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCD Camera
A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging. In a CCD image sensor, pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors. These MOS capacitors, the basic building blocks of a CCD, are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface; the CCD is then used to read out these charges. Although CCDs are not the only technology to allow for light detection, CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital cameras, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box. Introduced by IBM in 1956, HDDs were the dominant secondary storage device for general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern era of servers and personal computers, though personal computing devices produced in large volume, like cell phones and tablets, rely on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Panel
A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a photovoltaic system or solar array. Solar panels capture sunlight as a source of radiant energy, which is converted into electric energy in the form of direct current (DC) electricity. Arrays of a photovoltaic system can be used to generate solar electricity that supplies electrical equipment directly, or grid-connected photovoltaic system, feeds power back into an alternate current (AC) electric grid, grid via an solar inverter, inverter system. History In 1839, the ability of some materials to create an electrical charge from light exposure was first observed by the French physicist Edmond Becquerel. Though these initial solar panels were too inefficient for even simple electric devices, they were used as an instrument to measure light. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zerodur
Zerodur (notation of the manufacturer: ZERODUR®), registered trademarkof Schott AG, is a lithium-aluminosilicate glass-ceramic produced by Schott AG since 1968. It has been used for a number of very large telescope mirrors including GTC, Keck I, Keck II, and SOFIA, as well as some smaller telescopes (such as the GREGOR Solar Telescope). With its very low coefficient of thermal expansion (CTE) it can be used to produce mirrors that retain acceptable figures in extremely cold environments such as deep space. Although it has advantages for applications requiring a coefficient of thermal expansion less than that of borosilicate glass, it remains very expensive as compared to borosilicate. The tight tolerance on CTE, ±0.007 K−1, allows for its use in high-precision applications. Applications # Optics # Microlithography # Measurement technology Properties Zerodur has both an amorphous (vitreous) component and a crystalline component. Its most important properties are: * Particul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and Cat's whisker detector, detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found in only minut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Fiber
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The properties of the final CFRP product can be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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