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Qinetiq Zephyr
The Airbus Zephyr is a series of lightweight solar-powered unmanned aerial vehicles (UAV). The latest model is a high-altitude platform station capable of flying at for months at a time without fueling. It has a wingspan of and weighs . Development The Zephyr was originally designed and built in 2003 by the British defence contractor QinetiQ. In a 2008 demonstration for the US military, Zephyr 6 (a smaller-scale version) broke the official world record for the longest-duration unmanned flight, however its 82-hour flight at an altitude of did not set an official record because FAI officials were not involved in the flight. The Zephyr 7 holds the official endurance record for an unrefuelled, unmanned aerial vehicle with its flight from 9 to 23 July 2010, lasting 336 hours, 22 minutes and 8 seconds (14 days, 22 min, 8 s). It could remain airborne for months thanks to its solar cells and rechargeable batteries. Record claims have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-altitude Long Endurance
Atmospheric satellite (United States usage, abbreviated atmosat) or pseudo-satellite (British usage) is a marketing term for an aircraft that operates in the atmosphere at high altitudes for extended periods of time, in order to provide services conventionally provided by an artificial satellite orbiting in space. Atmospheric satellites remain aloft through atmospheric lift, either aerostatic/buoyancy (e.g., balloons) or aerodynamic (e.g., airplanes). By contrast, conventional satellites in Earth orbit operate in the vacuum of space and remain in flight through centrifugal force derived from their orbital speed. To date, all atmosats have been unmanned aerial vehicles (UAVs). Design principles An atmosat remains aloft through atmospheric lift, in contrast to a satellite in Earth orbit which moves freely at high speed in the vacuum of space, and orbits due to its centrifugal force matching the force of gravity. Satellites are expensive to build and launch, and any changes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligence, Surveillance, Target Acquisition, And Reconnaissance
ISTAR stands for intelligence, surveillance, target acquisition, and reconnaissance. In its macroscopic sense, ISTAR is a practice that links several battlefield functions together to assist a combat force in employing its sensors and managing the information they gather. Information is collected on the battlefield through systematic observation by deployed soldiers and a variety of electronic sensors. ''Surveillance'', ''target acquisition'' and ''reconnaissance'' are methods of obtaining this information. The information is then passed to intelligence personnel for analysis, and then to the commander and their staff for the formulation of battle plans. Intelligence is processed information that is relevant and contributes to an understanding of the ground, and of enemy dispositions and intents. Intelligence failures can happen. ISR (Intelligence, surveillance and reconnaissance) ISR is the coordinated and integrated acquisition, processing and provision of timely, accurat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIDAR
Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be used to make digital 3-D representations of areas on the Earth's surface and ocean bottom of the intertidal and near coastal zone by varying the wavelength of light. It has terrestrial, airborne, and mobile applications. ''Lidar'' is an acronym of "light detection and ranging" or "laser imaging, detection, and ranging". It is sometimes called 3-D laser scanning, a special combination of 3-D scanning and laser scanning. Lidar is commonly used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, atmospheric physics, laser guidance, airborne laser swath mapping (ALSM), and laser altimetry. It is also used in control and navigation for som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligence, Surveillance And Reconnaissance
ISTAR stands for intelligence, surveillance, target acquisition, and reconnaissance. In its macroscopic sense, ISTAR is a practice that links several battlefield functions together to assist a combat force in employing its sensors and managing the information they gather. Information is collected on the battlefield through systematic observation by deployed soldiers and a variety of electronic sensors. ''Surveillance'', ''target acquisition'' and ''reconnaissance'' are methods of obtaining this information. The information is then passed to intelligence personnel for analysis, and then to the commander and their staff for the formulation of battle plans. Intelligence is processed information that is relevant and contributes to an understanding of the ground, and of enemy dispositions and intents. Intelligence failures can happen. ISR (Intelligence, surveillance and reconnaissance) ISR is the coordinated and integrated acquisition, processing and provision of timely, accurat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Site
A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjacent cells, in a cellular network. The raised structure typically supports antenna and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiver for timing (for CDMA2000/IS-95 or GSM systems), primary and backup electrical power sources, and sheltering. Multiple cellular providers often save money by mounting their antennas on a common shared mast; since separate systems use different frequencies, antennas can be located close together without interfering with each other. Some provider companies operate multiple cellular networks and similarly use colocated base stations for two or more cellular networks, ( CDMA2000 or GSM, for example). Some cities require that cell sites b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Mechanics
''Popular Mechanics'' (sometimes PM or PopMech) is a magazine of popular science and technology, featuring automotive, home, outdoor, electronics, science, do-it-yourself, and technology topics. Military topics, aviation and transportation of all types, space, tools and gadgets are commonly featured. It was founded in 1902 by Henry Haven Windsor, who was the editor and—as owner of the Popular Mechanics Company—the publisher. For decades, the tagline of the monthly magazine was "Written so you can understand it." In 1958, PM was purchased by the Hearst Corporation, now Hearst Communications. In 2013, the US edition changed from twelve to ten issues per year, and in 2014 the tagline was changed to "How your world works." The magazine added a podcast in recent years, including regular features ''Most Useful Podcast Ever'' and ''How Your World Works''. History ''Popular Mechanics'' was founded in Chicago by Henry Haven Windsor, with the first issue dated January 11, 1902. ... [...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] |
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Four Corners region with Utah to the north, Colorado to the northeast, and New Mexico to the east; its other neighboring states are Nevada to the northwest, California to the west and the Mexican states of Sonora and Baja California to the south and southwest. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GaAs
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells and optical windows. GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors, including indium gallium arsenide, aluminum gallium arsenide and others. Preparation and chemistry In the compound, gallium has a +3 oxidation state. Gallium arsenide single crystals can be prepared by three industrial processes: * The vertical gradient freeze (VGF) process. * Crystal growth using a horizontal zone furnace in the Bridgman-Stockbarger technique, in which gallium and arsenic vapors react, and free molecules deposit on a seed crystal at the cooler end of the furnace. * Liquid encapsulated Czochralski (LEC) growth is used for producing high-puri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Energy
Specific energy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy density, which is defined as energy per unit volume. It is used to quantify, for example, stored heat and other thermodynamic properties of substances such as specific internal energy, specific enthalpy, specific Gibbs free energy, and specific Helmholtz free energy. It may also be used for the kinetic energy or potential energy of a body. Specific energy is an intensive property, whereas energy and mass are extensive property, extensive properties. The International System of Units, SI unit for specific energy is the joule per kilogram (J/kg). Other units still in use in some contexts are the kilocalorie per gram (Cal/g or kcal/g), mostly in food-related topics, watt hours per kilogram in the field of batteries, and the Imperial System, Imperial unit BTU per pound (mass), pound (Btu/lb), in some engineering and applied technic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanowire Battery
A nanowire battery uses nanowires to increase the surface area of one or both of its electrodes. Some designs (silicon, germanium and transition metal oxides), variations of the lithium-ion battery have been announced, although none are commercially available. All of the concepts replace the traditional graphite anode and could improve battery performance. Silicon Silicon is an attractive material for applications as lithium battery anodes because it offers advantageous material properties. In particular, silicon has a low discharge potential and a high theoretical charge capacity ten times higher than that of typical graphite anodes currently used in industry. Nanowires could improve these properties by increasing the amount of available surface area in contact with the electrolyte, thereby increasing the anode’s power density and allowing for faster charging and higher current delivery. However, the use of silicon anodes in batteries has been limited by the volume expansion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
