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Foot-lambert
A foot-lambert or footlambert (fL, sometimes fl or ft-L) is a unit of luminance in United States customary units and some other unit systems. A foot-lambert equals 1/π or 0.3183 candela per square foot, or 3.426 candela per square meter (the corresponding SI unit). The foot-lambert is named after Johann Heinrich Lambert (1728–1777), a Swiss-German mathematician, physicist and astronomer. It is rarely used by electrical and lighting engineers, who prefer the candela per square foot or candela per square meter units. The luminance of a perfect Lambertian diffuse reflecting surface in foot-lamberts is equal to the incident illuminance in foot-candles. For real diffuse reflectors, the ratio of luminance to illuminance in these units is roughly equal to the reflectance of the surface. Mathematically, :L_\mathrm v = E_\mathrm v \times R, where :L_\mathrm v is the luminance, in foot-lamberts, :E_\mathrm v is the illuminance, in foot-candles, and :R is the reflectivity, expressed as a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apostilb
The apostilb is an obsolete unit of luminance. The SI unit of luminance is the candela per square metre (cd/m2). In 1942 Parry Moon proposed to rename the apostilb the blondel, after the French physicist André Blondel. The symbol for the apostilb is asb. The apostilb is defined in terms of another unit of luminance, the Stilb (unit), stilb (sb): :1 asb = 1/ ⋅ 10−4 sb : asb = 1 cd/m2 See also Other units of luminance: * Lambert (unit), Lambert (L) * Skot (unit), Skot (sk) * Bril (unit), Bril (bril) * Nit (unit), Nit (nit) * Foot-lambert (fL) References {{reflist Units of luminance Centimetre–gram–second system of units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminance
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle. Brightness is the term for the ''subjective'' impression of the ''objective'' luminance measurement standard (see for the importance of this contrast). The SI unit for luminance is candela per square metre (cd/m2). A non-SI term for the same unit is the nit. The unit in the Centimetre–gram–second system of units (CGS) (which predated the SI system) is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. Description Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. Luminance levels indicate how much luminous power could be detected by the human eye looking at a particular surface from a particular angle of view. Luminance is thus an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nit (unit)
NiT, NIT or Nits may refer to: Education * Narula Institute of Technology, West Bengal, India * National Institutes of Technology, India * Naval Institute of Technology, Biliran, Philippines * Nippon Institute of Technology, Japan * Northern Institute of Technology Management, Germany * Babol Noshirvani University of Technology, Iran Science and technology * Nit, the egg case of a head louse * Nit (unit), of luminance * Nat (unit) or nit, natural unit of information * Network Investigative Technique, computer malware used by the FBI Other uses * National Invitation Tournament, for US men's college basketball * Nagpur Improvement Trust, India * Nits (band), a Dutch musical group * ''National Indigenous Times'', indigenous Australian affairs newspaper * Negative income tax * Neith or Nit, ancient Egyptian goddess * Norfolk International Terminals, facility of the Virginia Port Authority, US * Notice inviting tenders, Indian equivalent of invitation to tender An invitation t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bril (unit)
The bril is an old, non- SI, unit of luminance. The SI unit of luminance is the candela per square metre. Unit conversions See also * Photometry (optics) Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy (including light) in terms of absolute power. ... Units of luminance Centimetre–gram–second system of units {{optics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skot (unit)
Skot (symbol: sk) is an old and deprecated measurement unit of luminance, used for self-luminous objects (''dark luminance''). Unit conversions See also * Photometry (optics) Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy (including light) in terms of absolute power. I ... {{SI light units Units of luminance Centimetre–gram–second system of units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blondel (unit)
Blondel may refer to: * Apostilb, an old unit of luminance * Blondel (surname) * Blondel de Nesle (c. 1155 – 1202), French trouvère, or poet * Jean-François Blondel (1683–1756), French architect * Maurice Blondel (1861–1949), French philosopher * Vincent Blondel (born 1965), Belgian applied mathematician * Amazing Blondel, an English progressive folk band ** Blondel (album), ''Blondel'' (album), a 1973 album by the band * Blondel (musical), ''Blondel'' (musical), a rock opera See also * Blondell, a surname and given name * Blondeau, a French surname * Blondin (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stilb (unit)
The stilb (sb) is the CGS unit of luminance for objects that are not self-luminous. It is equal to one candela per square centimeter or 104 nits (candelas per square meter). The name was coined by the French physicist André Blondel around 1920. It comes from the Greek word (), meaning 'to glitter'. It was in common use in Europe up to World War I. In North America self-explanatory terms such as candle per square inch and candle per square meter were more common. The unit has since largely been replaced by the SI unit: candela per square meter The candela per square metre (symbol: cd/m2) is the unit of luminance in the International System of Units (SI). The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area. The nit (symbol: nt) .... The current national standard for SI in the United States discourages the use of the stilb.IEEE/ASTM SI 10-2002. ''American National Standard for Use of the International System of Units (SI) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nit (unit)
NiT, NIT or Nits may refer to: Education * Narula Institute of Technology, West Bengal, India * National Institutes of Technology, India * Naval Institute of Technology, Biliran, Philippines * Nippon Institute of Technology, Japan * Northern Institute of Technology Management, Germany * Babol Noshirvani University of Technology, Iran Science and technology * Nit, the egg case of a head louse * Nit (unit), of luminance * Nat (unit) or nit, natural unit of information * Network Investigative Technique, computer malware used by the FBI Other uses * National Invitation Tournament, for US men's college basketball * Nagpur Improvement Trust, India * Nits (band), a Dutch musical group * ''National Indigenous Times'', indigenous Australian affairs newspaper * Negative income tax * Neith or Nit, ancient Egyptian goddess * Norfolk International Terminals, facility of the Virginia Port Authority, US * Notice inviting tenders, Indian equivalent of invitation to tender An invitation t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambert (unit)
The lambert (symbol L, la or Lb) is a non- SI metric unit of luminance named for Johann Heinrich Lambert (1728–1777), a Swiss mathematician, physicist and astronomer. A related unit of luminance, the foot-lambert, is used in the lighting, cinema and flight simulation industries. The SI unit is the candela per square metre (cd/m2). Definition 1 lambert (L) = \frac candela per square centimetre (0.3183 cd/cm2) or \frac cd m−2 See also Other units of luminance: * Apostilb The apostilb is an obsolete unit of luminance. The SI unit of luminance is the candela per square metre (cd/m2). In 1942 Parry Moon proposed to rename the apostilb the blondel, after the French physicist André Blondel. The symbol for the apostilb i ... (asb) * Blondel (blondel) * Bril (bril) * Nit (nit) * Stilb (sb) * Skot (sk) {{SI light units References "Lighting Design Glossary: Luminance" at ''Schorsch Lighting Design Knowledgebase'' Units of luminance Non-SI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Aviation Authorities
The Joint Aviation Authorities (JAA) was an associated body of the European Civil Aviation Conference representing the civil aviation regulatory authorities of a number of European States who had agreed to co-operate in developing and implementing common safety regulatory standards and procedures. It was not a regulatory body, regulation being achieved through the member authorities. It was in existence from 1970 until disbanded in 2009. Its headquarters were located in Hoofddorp near Schiphol airport in Netherlands. JAA issued the Joint Aviation Requirements (JAR), intended to establish minimum requirements for air safety. In implementing the so-called FUJA Report, the JAA had entered into a new phase as of 1 January 2007. In this new phase the former "JAA" had become "JAA T" (Transition). JAA T consisted of a Liaison Office (JAA LO) and a Training Office (JAA TO). The offices of JAA LO were located in the premises of European Aviation Safety Agency (E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Aviation Administration
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic management, certification of personnel and aircraft, setting standards for airports, and protection of U.S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization. Created in , the FAA replaced the former Civil Aeronautics Administration (CAA) and later became an agency within the U.S. Department of Transportation. Major functions The FAA's roles include: *Regulating U.S. commercial space transportation *Regulating air navigation facilities' geometric and flight inspection standards *Encouraging and developing civil aeronautics, including new aviation technology *Issuing, suspending, or revoking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Simulation Training Device
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be achieved by generating aerodynamic lift associated with gliding or propulsive thrust, aerostatically using buoyancy, or by ballistic movement. Many things can fly, from animal aviators such as birds, bats and insects, to natural gliders/parachuters such as patagial animals, anemochorous seeds and ballistospores, to human inventions like aircraft (airplanes, helicopters, airships, balloons, etc.) and rockets which may propel spacecraft and spaceplanes. The engineering aspects of flight are the purview of aerospace engineering which is subdivided into aeronautics, the study of vehicles that travel through the atmosphere, and astronautics, the study of vehicles that travel through space, and ballistics, the study of the flight of projectil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
