Image of two persons in mid-infrared ("thermal") light (false-color)

Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light with the longest wavelength. Infrared radiation has wavelengths between about 750 nm and 1 mm, spanning three orders of magnitude.^[1] Infrared may mean: The infrared range of light. ... Image File history File links Download high-resolution version (1159x768, 124 KB) Author: User:Cody. ... Image File history File links Download high-resolution version (1159x768, 124 KB) Author: User:Cody. ... A false color image showing the Chesapeake Bay and the city of Baltimore. ... Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... The wavelength is the distance between repeating units of a wave pattern. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Radio waves are electromagnetic waves occurring on the radio frequency portion of the electromagnetic spectrum. ... For other uses, see Red (disambiguation). ... For other uses, see Latin (disambiguation). ... Color is an important part of the visual arts. ... This article does not cite any references or sources. ... A nanometre (American spelling: nanometer, symbol nm) is a unit of length in the metric system, equal to one thousand-millionth of a metre, which is the current SI base unit of length. ... A millimetre (American spelling: millimeter, symbol mm) is an SI unit of length that is equal to one thousandth of a metre. ...

The uses of infrared include military, such as: target acquisition, surveillance, homing and tracking and non-military, such as thermal efficiency analysis, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space, such as molecular clouds; detect cool objects such as planets, and to view highly red-shifted objects from the early days of the universe.^[2] Target acquisition provides detailed information about enemy forces and locates them with sufficient accuracy to permit continued monitoring or target designation and engagement. ... Extremely high resolution spectrogram of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of the interaction between radiation (electromagnetic radiation, or light, as well as particle radiation) and matter. ... Infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in infrared (IR) radiation. ... 50 cm refracting telescope at Nice Observatory. ... A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ... This article is about the astronomical term. ... Redshift of spectral lines in the optical spectrum of a supercluster of distant galaxies (right), as compared with that of the Sun (left). ... For other uses, see Universe (disambiguation). ...

At the atomic level, infrared energy elicits vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states. Infrared spectroscopy examines absorption and transmission of photons in the infrared energy range, based on their frequency and intensity.^[3] For other uses, see Atom (disambiguation). ... Look up vibration in Wiktionary, the free dictionary. ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... This article is about the electromagnetic phenomenon. ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ...

Origins of the term

The name means "below red" (from latin infra, "below"), red being the color of the longest wavelengths of visible light. IR light has a longer wavelength than that of red light. For other uses, see Latin (disambiguation). ...

Different regions in the infrared

Objects generally emit infrared radiation across a spectrum of wavelengths, but only a specific region of the spectrum is of interest because sensors are usually designed only to collect radiation within a specific bandwidth. As a result, the infrared band is often subdivided into smaller sections. There are no standard divisions, but a commonly used scheme is:^{[citation needed]}

• Near-infrared (NIR, IR-A DIN): 0.75-1.4 µm in wavelength, defined by the water absorption, and commonly used in fiber optic telecommunication because of low attenuation losses in the SiO₂ glass (silica) medium. Image intensifiers are sensitive to this area of the spectrum. Examples include night vision devices such as night vision goggles.

• Short-wavelength infrared (SWIR, IR-B DIN): 1.4-3 µm, water absorption increases significantly at 1,450 nm. The 1,530 to 1,560 nm range is the dominant spectral region for long-distance telecommunications

• Mid-wavelength infrared (MWIR, IR-C DIN) also called intermediate infrared (IIR): 3-8 µm. In guided missile technology this is the 'heat seeking' region in which the homing heads of passive IR homing missiles are designed to work, homing on to the IR signature of the target aircraft, typically the jet engine exhaust plume.

• Long-wavelength infrared (LWIR, IR-C DIN): 8–15 µm. This is the "thermal imaging" region, in which sensors can obtain a completely passive picture of the outside world based on thermal emissions only and requiring no external light or thermal source such as the sun, moon or infrared illuminator. Forward-looking infrared (FLIR) systems use this area of the spectrum. Sometimes also called the "far infrared."

• Far infrared (FIR): 15-1,000 µm (see also far infrared laser)

NIR and SWIR is sometimes called reflected infrared while MWIR and LWIR is sometimes referred to as thermal infrared. Due to the nature of the blackbody radiation curves, typical 'hot' objects, such as exhaust pipes, often appear brighter in the MW compared to the same object viewed in the LW. Look up din in Wiktionary, the free dictionary. ... A micrometre (American spelling: micrometer, symbol µm) is an SI unit of length equal to one millionth of a metre, or about a tenth of the diameter of a droplet of mist or fog. ... Fiber Optic strands An optical fiber in American English or fibre in British English is a transparent thin fiber for transmitting light. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... A forward looking infrared (FLIR) system is a television camera that takes pictures in infrared. ... Far infrared laser (FIR laser, terahertz laser) is a laser with output wavelength in far infrared part of the electromagnetic spectrum, between 30-1000 µm (10 THz-300 GHz). ...

Astronomers typically divide the infrared spectrum as follows:^[4]

• near: (0.7-1) to 5 µm
• mid: 5 to (25-40) µm
• long: (25-40) to (200-350) µm

These divisions are not precise and can vary depending on the publication. The three regions are used for observation of different temperature ranges, and hence different environments in space.

A third scheme divides up the band based on the response of various detectors:^[5]

• Near infrared (NIR): from 0.7 to 1.0 micrometers (from the approximate end of the response of the human eye to that of silicon)
• Short-wave infrared (SWIR): 1.0 to 3 micrometers (from the cut off of silicon to that of the MWIR atmospheric window. InGaAs covers to about 1.8 micrometers; the less sensitive lead salts cover this region
• Mid-wave infrared (MWIR): 3 to 5 micrometers (defined by the atmospheric window and covered by InSb and HgCdTe and partially PbSe)
• Long-wave infrared (LWIR): 8 to 12, or 7 to 14 micrometers: the atmospheric window (Covered by HgCdTe and microbolometers)
• Very-long wave infrared (VLWIR): 12 to about 30 micrometers, covered by doped silicon

These divisions are justified by the different human response to this radiation: near infrared is the region closest in wavelength to the radiation detectable by the human eye, mid and far infrared are progressively further from the visible regime. Other definitions follow different physical mechanisms (emission peaks, vs. bands, water absorption) and the newest follow technical reasons (The common silicon detectors are sensitive to about 1,050 nm, while InGaAs' sensitivity starts around 950 nm and ends between 1,700 and 2,600 nm, depending on the specific configuration). Unfortunately, international standards for these specifications are not currently available. A micrometre (American spelling: micrometer), symbol µm, is an SI unit of length. ... A Microbolometer is a specific type of bolometer used as a detector in a thermal camera. ... “Visible light” redirects here. ... Not to be confused with Silicone. ... Indium gallium arsenide (InGaAs) is a semiconductor composed of indium, gallium and arsenic. ...

The boundary between visible and infrared light is not precisely defined. The human eye is markedly less sensitive to light above 700 nm wavelength, so shorter frequencies make insignificant contributions to scenes illuminated by common light sources. But particularly intense light (e.g., from lasers, or from bright daylight with the visible light removed by colored gels[1]) can be detected up to approximately 780 nm, and will be perceived as red light. The onset of infrared is defined (according to different standards) at various values typically between 700 nm and 800 nm. Plot of atmospheric transmittance in the infrared region of the EM spectrum. ... For other uses, see Eye (disambiguation). ... For other uses, see Laser (disambiguation). ...

Telecommunication bands in the infrared

In optical communications, the part of the infrared spectrum that is used is divided into several bands based on availability of light sources, transmitting/absorbing materials (fibers) and detectors:^[6] Optical communication is any form of telecommunication that uses light as the transmission medium. ...

The C-band is the dominant band for long-distance telecommunication networks. The S and L bands are based on less well established technology, and are not as widely deployed. Copy of the original phone of Alexander Graham Bell at the Musée des Arts et Métiers in Paris Telecommunication is the transmission of signals over a distance for the purpose of communication. ...

Heat

Main article: Thermal radiation

Infrared radiation is popularly known as "heat" or sometimes "heat radiation", since many people attribute all radiant heating to infrared light and/or to all infrared radiation to being a result of heating. This is a widespread misconception, since light and electromagnetic waves of any frequency will heat surfaces that absorb them. Infrared light from the Sun only accounts for 49%^[7] of the heating of the Earth, the rest being caused by visible light that is absorbed then re-radiated at longer wavelengths. Visible light or ultraviolet-emitting lasers can char paper and incandescently hot objects emit visible radiation. It is true that objects at room temperature will emit radiation mostly concentrated in the 8 to 12 micrometer band, but this is not distinct from the emission of visible light by incandescent objects and ultraviolet by even hotter objects (see black body and Wien's displacement law).^[8] “Radiant heat” redirects here. ... For other uses, see Ultraviolet (disambiguation). ... For other uses, see Laser (disambiguation). ... For other uses, see Temperature (disambiguation). ... Spontaneous emission is the process by which a molecule in an excited state drops to the ground state, resulting in the creation of a photon. ... “Radiant heat” redirects here. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... Wiens displacement law is a law of physics that states that there is an inverse relationship between the wavelength of the peak of the emission of a black body and its temperature. ...

Heat is energy in transient form that flows due to temperature difference. Unlike heat transmitted by thermal conduction or thermal convection, radiation can propagate through a vacuum. For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ... Heat flow along perfectly insulated wire Conduction is the transfer of heat or electric current from one substance to another by direct contact. ... Convection is the internal movement of currents within fluids (i. ... Look up Vacuum in Wiktionary, the free dictionary. ...

The concept of emissivity is important in understanding the infrared emissions of objects. This is a property of a surface which describes how its thermal emissions deviate from the ideal of a blackbody. To further explain, two objects at the same physical temperature will not 'appear' the same temperature in an infrared image if they have differing emissivities. The emissivity of a material (usually written ) is the ratio of energy radiated by the material to energy radiated by a black body at the same temperature. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ...

Applications

Shortcut: WP:-( Vandalism is indisputable bad-faith addition, deletion, or change to content, made in a deliberate attempt to compromise the integrity of the encyclopedia. ... Shortcut: WP:-( Vandalism is indisputable bad-faith addition, deletion, or change to content, made in a deliberate attempt to compromise the integrity of the encyclopedia. ...

Infrared Filters

Main article: Night vision

Infrared (IR) filters are made of polysulphone plastic that blocks over 99% of the visible light spectrum from any “white” light source. Infrared filters allow a maximum of infrared output while maintaining extreme covertness. Currently in use around the world, infrared filters are used in Military, Law Enforcement, Industrial and Commercial applications. The unique makeup of the plastic allows for maximum durability and heat resistance. IR filters provide a more cost effective and time efficient solution over the standard bulb replacement alternative. All Generations of night vision devices are greatly enhanced with the use of IR Filters. Night-vision is seeing in the dark. ...

Night vision

Main article: Night vision

Infrared is used in night vision equipment when there is insufficient visible light to see.^[9] Night vision devices operate through a process involving the conversion of ambient light photons into electrons which are then amplified by a chemical and electrical process and then converted back into visible light.^[9] Infrared light sources can be used to augment the available ambient light for conversion by night vision devices, increasing in-the-dark visibility without actually using a visible light source.^[9] Night-vision is seeing in the dark. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... An American soldier uses a helmet mounted night vision device A night vision device (NVD) is an optical instrument that allows images to be produced in levels of light approaching total darkness. ...

The use of infrared light and night vision devices should not be confused with thermal imaging which creates images based on differences in surface temperature by detecting infrared radiation (heat) that emanates from objects and their surrounding environment ^[10] Thermography can refer to a printing process and a imaging process. ... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ...

Thermography

Main article: Thermography

A thermographic image of a dog

Infrared thermography is a non-contact, non-destructive test method that utilizes a thermal imager to detect, display and record thermal patterns and temperatures across the surface of an object. Infrared thermography may be applied to any situation where knowledge of thermal profiles and temperatures will provide meaningful data about a system, object or process. Thermography is widely used in industry for predictive maintenance, condition assessment, quality assurance, and forensic investigations of electrical, mechanical and structural systems. Other applications include, but are not limited to: law enforcement, firefighting, search and rescue, and medical and veterinary sciences. This article is about the infrared imaging technique. ... Image File history File links Infrared_dog. ... Image File history File links Infrared_dog. ... Predictive maintenance (PdM) techniques help determine the condition of in-service equipment in order to predict when maintenance bumpersqwat should be performed. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... Agents of the United States Army Criminal Investigation Division investigate a crime scene Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ... For the band, see The Police. ... Firefighter with an axe A firefighter, sometimes still called a fireman though women have increasingly joined firefighting units, is a person who is trained and equipped to put out fires, rescue people and in some areas provide emergency medical services. ... Search and Rescue (acronym SAR) is an operation mounted by emergency services, often well-trained volunteers, to find someone believed to be in distress, lost, sick or injured either in a remote or difficult to access area, such as mountains, desert or forest (Wilderness search and rescue), or at sea... For the chemical substances known as medicines, see medication. ... Veterinary medicine is the application of medical diagnostic and therapeutic principles to companion, domestic, exotic, wildlife, and production animals. ...

Aside from test equipment, training is the most important investment a company will make in an infrared inspection program. Advances in technology have provided infrared equipment that is user-friendly; however, infrared thermography is not a simply "point and shoot" technology. In addition to understanding the object or system being inspected, thermographers must also understand common error sources that can influence observed thermal data. Typically, infrared training courses should cover the topics of infrared theory, heat transfer concepts, equipment selection and operation, how to eliminate or overcome common error sources, and specific applications. Training courses from independent training companies are preferred since they are not biased toward a single brand or type of equipment. A point and shoot camera, also called a compact camera, is a still camera designed primarily for simple operation. ...

Other imaging

Infrared light from the LED of a remote control as seen by a digital camera.

In infrared photography, infrared filters are used to capture the near-infrared spectrum. Digital cameras often use infrared blockers. Cheaper digital cameras and camera phones have less effective filters and can "see" intense near-infrared, appearing as a bright purple-white color (try pointing a TV remote at your digital camera). This is especially pronounced when taking pictures of subjects near IR-bright areas (such as near a lamp), where the resulting infrared interference can wash out the image. There is also a technique called 'T-ray' imaging, which is imaging using far infrared or terahertz radiation. Lack of bright sources makes terahertz photography technically more challenging than most other infrared imaging techniques. Recently T-ray imaging has been of considerable interest due to a number of new developments such as terahertz time-domain spectroscopy. Image File history File links Download high-resolution version (2560x1920, 328 KB) Summary compressed version of Image:P1020168. ... Image File history File links Download high-resolution version (2560x1920, 328 KB) Summary compressed version of Image:P1020168. ... External links LEd Category: TeX ... A television remote control A DVD Player remote control A remote control is an electronic device used for the remote operation of a machine. ... Top: tree photographed in the near infrared range. ... An infrared filter is a filter to remove visible light and only pass infrared light in different wavelenghts. ... A SiPix digital camera next to a matchbox to show scale Nikon D200 SLR with Nikon film scanner, which converts film images to digital A Hasselblad 503CW with a digital camera back A digital camera is an electronic device used to capture and store photographs digitally, instead of using photographic... A blocker is the inverse of a filter. ... A SiPix digital camera next to a matchbox to show scale Nikon D200 SLR with Nikon film scanner, which converts film images to digital A Hasselblad 503CW with a digital camera back A digital camera is an electronic device used to capture and store photographs digitally, instead of using photographic... A camera phone in use Camera phones are a type of cellphone which has a camera built in. ... Electromagnetic waves sent at terahertz frequencies, known as terahertz radiation, terahertz waves, terahertz light, T-rays, T-light, T-lux and THz, are in the region of the electromagnetic spectrum between 300 gigahertz (3x1011 Hz) and 3 terahertz (3x1012 Hz), corresponding to the wavelength range starting at submillimeter (<1 millimeter... The hertz (symbol: Hz) is the SI unit of frequency. ... In terahertz time domain spectroscopy (THz-TDS), picosecond pulses of terahertz radiation are used to probe different materials. ...

Tracking

Main article: Infrared homing

Infrared tracking, also known as infrared homing, refers to a passive missile guidance system which uses the emission from a target of electromagnetic radiation in the infrared part of the spectrum to track it. Missiles which use infrared seeking are often referred to as "heat-seekers", since infrared (IR) is just below the visible spectrum of light in frequency and is radiated strongly by hot bodies. Many objects such as people, vehicle engines and aircraft generate and retain heat, and as such, are especially visible in the infra-red wavelengths of light compared to objects in the background. Infra-red homing refers to a guidance system which uses the infra-red light emission from a target to track it. ... A guided bomb strikes an underground facility Missile guidance technologies of missile systems use a variety of methods to guide a missile to its intended target. ... This page is a list of sources of light. ... Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... Legend γ = Gamma rays HX = Hard X-rays SX = Soft X-Rays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...

Heating

Main article: Infrared heating

Infrared radiation can be used as a deliberate heating source. For example it is used in infrared saunas to heat the occupants, and also to remove ice from the wings of aircraft (de-icing). It is also gaining popularity as a method of heating asphalt pavements in place during new construction or in repair of damaged asphalt. Infrared can be used in cooking and heating food as it predominantly heats the opaque, absorbent objects, rather than the air around them. Infrared heating refers to heating objects (or people) through electromagnetic radiation. ... An infrared sauna is a sauna that heats its occupants with heaters that emit far infrared radiant heat. ... “Flying Machine” redirects here. ...

Infrared heating is also becoming more popular in industrial manufacturing processes, e.g. curing of coatings, forming of plastics, annealing, plastic welding, print drying. In these applications, infrared heaters replace convection ovens and contact heating. Efficiency is achieved by matching the wavelength of the infrared heater to the absorption characteristics of the material. An infrared heater is a body with a higher temperature which transfers energy to a body with a lower temperature through electromagnetic radiation. ...

Communications

IR data transmission is also employed in short-range communication among computer peripherals and personal digital assistants. These devices usually conform to standards published by IrDA, the Infrared Data Association. Remote controls and IrDA devices use infrared light-emitting diodes (LEDs) to emit infrared radiation which is focused by a plastic lens into a narrow beam. The beam is modulated, i.e. switched on and off, to encode the data. The receiver uses a silicon photodiode to convert the infrared radiation to an electric current. It responds only to the rapidly pulsing signal created by the transmitter, and filters out slowly changing infrared radiation from ambient light. Infrared communications are useful for indoor use in areas of high population density. IR does not penetrate walls and so does not interfere with other devices in adjoining rooms. Infrared is the most common way for remote controls to command appliances. Look up Personal digital assistant in Wiktionary, the free dictionary. ... The Infrared Data Association (IrDA) defines physical specifications communications protocol standards for the short range exchange of data over infrared light, for uses such as personal area networks (PANs). ... “LED” redirects here. ... This article is about the optical device. ... In telecommunications, modulation is the process of varying a periodic waveform, i. ... For other uses, see Data (disambiguation). ... Not to be confused with Silicone. ... Photodiode closeup A photodiode A photodiode is a semiconductor diode that functions as a photodetector. ... In electricity, current refers to electric current, which is the flow of electric charge. ... A television remote control A DVD Player remote control A remote control is an electronic device used for the remote operation of a machine. ...

Free space optical communication using infrared lasers can be a relatively inexpensive way to install a communications link in an urban area operating at up to 4 gigabit/s, compared to the cost of burying fiber optic cable. Free Space Optics (FSO) is a telecommunication technology that uses light propagating in free space to transmit data between two points. ... For other uses, see Laser (disambiguation). ...

Infrared lasers are used to provide the light for optical fiber communications systems. Infrared light with a wavelength around 1,330 nm (least dispersion) or 1,550 nm (best transmission) are the best choices for standard silica fibers. Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... Dispersion of a light beam in a prism. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ...

Spectroscopy

Infrared vibrational spectroscopy (see also near infrared spectroscopy) is a technique which can be used to identify molecules by analysis of their constituent bonds. Each chemical bond in a molecule vibrates at a frequency which is characteristic of that bond. A group of atoms in a molecule (e.g. CH₂) may have multiple modes of oscillation caused by the stretching and bending motions of the group as a whole. If an oscillation leads to a change in dipole in the molecule, then it will absorb a photon which has the same frequency. The vibrational frequencies of most molecules correspond to the frequencies of infrared light. Typically, the technique is used to study organic compounds using light radiation from 4000-400 cm^-1, the mid-infrared. A spectrum of all the frequencies of absorption in a sample is recorded. This can be used to gain information about the sample composition in terms of chemical groups present and also its purity (for example a wet sample will show a broad O-H absorption around 3200cm^-1). Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... Near infrared spectroscopy (NIRS) is a spectroscopic method utilising the near infra-red region of the electromagnetic spectrum (from 1100nm to 2500nm). ... The Earths magnetic field, which is approximately a dipole. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy...

Meteorology

IR Satellite picture taken 1315 Z on 15th October 2006. A frontal system can be seen in the Gulf of Mexico with embedded Cumulonimbus cloud. Shallower Cumulus and Stratocumulus can be seen off the Eastern Seaboard.

Weather satellites equipped with scanning radiometers produce thermal or infrared images which can then enable a trained analyst to determine cloud heights and types, to calculate land and surface water temperatures, and to locate ocean surface features. The scanning is typically in the range 10.3-12.5 µm (IR4 and IR5 channels). Image File history File links US_IR_satpic. ... Image File history File links US_IR_satpic. ... A guide to the symbols for weather fronts that may be found on a weather map: 1. ... Gulf of Mexico in 3D perspective. ... Categories: US geography stubs ... GOES-8, a United States weather satellite. ...

High, cold ice cloud such as Cirrus or Cumulonimbus show up bright white, lower warmer cloud such as Stratus or Stratocumulus show up as grey with intermediate clouds shaded accordingly. Hot land surfaces will show up as dark grey or black. One disadvantage of infrared imagery is that low cloud such as stratus or fog can be a similar temperature to the surrounding land or sea surface does not show up. However using the difference in brightness of the IR4 channel (10.3-11.5 µm) and the near-infrared channel (1.58-1.64 µm), low cloud can be distinguished, producing a fog satellite picture. The main advantage of infrared is that images can be produced at night, allowing a continuous sequence of weather to be studied. Cirrus can refer to: a type of cloud, cirrus cloud a car produced by DaimlerChrysler, Chrysler Cirrus a German rocket, cirrus (rocket) a trance music group, Cirrus (music group) an interbank network (ATM network) by MasterCard, Cirrus (interbank network) a British aircraft engine company, Cirrus Engine an aircraft company, Cirrus... Cumulonimbus cloud in central Oklahoma. ... A Stratus cloud is a cloud belonging to a class characterized by horizontal layering with a uniform base, as opposed to convective clouds that are as tall or taller than wide (these are termed Cumulus clouds). ... A stratocumulus cloud is a cloud belonging to a class characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumulus and the whole being at a lower altitude, usually below 2400 m (8000 ft). ... Golden Gate Bridge in Fog Evening fog obscures Londons Tower Bridge from passers by. ...

These infrared pictures can 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. Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. ...

Climatology

In the field of climatology, atmospheric infrared radiation is monitored to detect trends in the energy exchange between the earth and the atmosphere. These trends provide information on long term changes in the earth's climate. It is one of the primary parameters studied in research into global warming together with solar radiation. Global warming refers to the increase in the average temperature of the Earths near-surface air and oceans in recent decades and its projected continuation. ... Solar irradiance spectrum at top of atmosphere. ...

A pyrgeometer is utilized in this field of research to perform continuous outdoor measurements. This is a broadband infrared radiometer with sensitivity for infrared radiation between approximately 4.5 µm and 50 µm. A pyrgeometer is a radiometer that is sensitive to broadband thermal irradiance, in the spectral range from approximately 3. ...

Example of a pyrgeometer. Model shown CGR 4. Picture courtesy of Kipp & Zonen BV. http://www.kippzonen.com/pyrgeometer

Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

Astronomy

The Spitzer Space Telescope is a dedicated infrared space observatory currently in orbit around the Sun. (Note the black side to the telescope, to maximize infrared radiation.) NASA image.

Main articles: infrared astronomy and far infrared astronomy

Astronomers observe objects in the infrared portion of the electromagnetic spectrum using optical components, including mirrors, lenses and solid state digital detectors. For this reason it is classified as part of optical astronomy. To form an image, the components of an infrared telescope need to be carefully shielded from heat sources, and the detectors are chilled using liquid helium. Image File history File linksMetadata Download high-resolution version (1933x3000, 1214 KB) Image: Telescope Spitzer Image provided by website Spitzer Space Telescope - NASA -JPL - CALTECH. Source: http://www. ... Image File history File linksMetadata Download high-resolution version (1933x3000, 1214 KB) Image: Telescope Spitzer Image provided by website Spitzer Space Telescope - NASA -JPL - CALTECH. Source: http://www. ... The Spitzer Space Telescope (formerly the Space Infrared Telescope Facility [SIRTF]) is an infrared space observatory, the fourth and final of NASAs Great Observatories. ... This article is about the American space agency. ... Infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in infrared (IR) radiation. ... Far infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in far-infrared radiation (approximatively from 30&#956;m to 300&#956;m). ... Optical astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light. ... For other uses, see Helium (disambiguation). ...

The sensitivity of Earth-based infrared telescopes is significantly limited by water vapor in the atmosphere, which absorbs a portion of the infrared radiation arriving from space outside of selected atmospheric windows. This limitation can be partially alleviated by placing the telescope observatory at a high altitude, or by carrying the telescope aloft with a balloon or an aircraft. Space telescopes do not suffer from this handicap, and so outer space is considered the ideal location for infrared astronomy. The atmospheric window refers to those parts of the electromagnetic spectrum that are, with the earths atmosphere in its natural state, not absorbed at all. ...

The infrared portion of the spectrum has several useful benefits for astronomers. Cold, dark molecular clouds of gas and dust in our galaxy will glow with radiated heat as they are irradiated by imbedded stars. Infrared can also be used to detect protostars before they begin to emit visible light. Stars emit a smaller portion of their energy in the infrared spectrum, so nearby cool objects such as planets can be more readily detected. (In the visible light spectrum, the glare from the star will drown out the reflected light from a planet.) A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ... A Protonononostar is an object that forms by contraction out of the really big gas of a giant molecular cloud in the interstellar medium. ... This article is about the astronomical term. ...

Infrared light is also useful for observing the cores of active galaxies which are often cloaked in gas and dust. Distant galaxies with a high redshift will have the peak portion of their spectrum shifted toward longer wavelengths, so they are more readily observed in the infrared.^[2] An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... Redshift of spectral lines in the optical spectrum of a supercluster of distant galaxies (right), as compared with that of the Sun (left). ...

Art history and Archaeology

The Arnolfini Portrait by Jan van Eyck, National Gallery, London

Infra-red (as art historians call them) reflectograms are taken of paintings to reveal underlying layers, in particular the underdrawing or outline drawn to by the artist as a guide. This often uses carbon black which shows up well in reflectograms, so long as it has not also been used in the ground underlying the whole painting. Art historians are looking to see if the visible layers of paint differ from the under-drawing or layers in between - such alterations are called pentimenti when made by the original artist. This is very useful information in deciding whether a painting is the prime version by the original artist or a copy, and whether it has been altered by over-enthusiatic restoration work. Generally the more pentimenti, the more likely a painting is to be the prime version. It also gives useful insights into working practices. [2] Image File history File links Download high resolution version (2024x2777, 366 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Renaissance Jan van Eyck Early Renaissance painting Early Netherlandish painting The Arnolfini portrait Giovanni Arnolfini Wikipedia:List of... Image File history File links Download high resolution version (2024x2777, 366 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Renaissance Jan van Eyck Early Renaissance painting Early Netherlandish painting The Arnolfini portrait Giovanni Arnolfini Wikipedia:List of... The Arnolfini Portrait (full title: Portrait of Giovanni Arnolfini and his Wife) is a 1434 painting by Jan van Eyck. ... This article needs additional references or sources for verification. ... Londons National Gallery, founded in 1824, houses a rich collection of over 2,300 paintings dating from the mid-13th century to 1900 in its home on Trafalgar Square. ... Underdrawing is the drawing done on a painting ground before paint is applied, for example, an imprimatura or an underpainting. ... Carbon black is a material, today usually produced by the incomplete combustion of petroleum products. ... In painting, pentimento is the growing transparency in paints with age causing underlying elements to show through. ...

Among many other changes in the Arnolfini Portrait of 1434 (right), his face was higher by about the height of his eye, hers was higher, and her eyes looked more to the front. Each of his feet was underdrawn in one position, painted in another, and then overpainted in a third. These alterations are seen in infra-red reflectograms.^[11] The Arnolfini Portrait, The Arnolfini Wedding, The Arnolfini Marriage or the Portrait of Giovanni Arnolfini and his Wife (or various other titles) is a 1434 painting in oil on oak panel by the Early Netherlandish painter Jan van Eyck. ...

Similar uses of infrared are made by archaeologists on various types of objects, especially very old written documents such as the Dead Sea Scrolls, the Roman works in the Villa of the Papyri, and the Silk Road texts found in the Dunhuang Caves.^[12] Carbon black used in ink can show up extremely well. The Dead Sea scrolls comprise roughly 900 documents, including texts from the Hebrew Bible, discovered between 1947 and 1956 in eleven caves in and around the Wadi Qumran (near the ruins of the ancient settlement of Khirbet Qumran, on the northwest shore of the Dead Sea) in the West Bank. ... The Villa of the Papyri is a private house of ancient Roman city of Herculaneum (current commune of Ercolano) owned by Julius Caesars father-in-law, Lucius Calpurnius Piso Caesoninus: its remains were first excavated in 1765 by Karl Weber. ... The Mogao Caves, or Mogao Grottoes (Chinese: ; Pinyin: ) form a system of 492 temples 25km (15. ...

Biological systems

Thermographic image of a snake eating a mouse

The pit viper is known to have two infrared sensory pits on its head. There is controversy over the exact thermal sensitivity of this biological infrared detection system.^[13][14] Image File history File links Wiki_snake_eats_mouse. ... Image File history File links Wiki_snake_eats_mouse. ... {{Taxobox[[{| class=wikitable |- ]]</nowiki>]] --> </gallery> |} |}]]| [[Image:[[Media:Failed to parse (unknown error): == <nowiki>#REDIRECT [[<sup><small>[ == == == [[Image:[[Image:[[Media:[[Media:#REDIRECT [[#REDIRECT [[#REDIRECT [[ ---- ---- <math><math><math>[[Media:[[Media: == == == == == == [[[[[[color = pink]]]]]] == == == == == ==]]]] </math></math>]]]]]]]]]]]]]] == == ==]]]</nowiki> ==</math>]]]] | name = Crotalinae | image = TimberRattler. ...

Other organisms that actively employ thermo-receptors are rattlesnakes (Crotalinae subfamily) and boas (Boidae family), the Common Vampire Bat (Desmodus rotundus), a variety of jewel beetles (Melanophila acuminata)^[15], darkly pigmented butterflies (Pachliopta aristolochiae and Troides rhadamathus plateni), and possibly blood-sucking bugs (Triatoma infestans).^[16] Species 27 species; see list of rattlesnake species and subspecies. ... This article is about the Korean pop singer. ... Binomial name Desmodus rotundus Geoffroy, 1810 The Common Vampire Bat (Desmodus rotundus) is a species of vampire bat. ... Genera about 450 genera The jewel beetles or metallic wood-boring beetles are a family Buprestidae of beetles known for their glossy iridescent colors. ... Binomial name Atrophaneura (Pachliopta) aristolochiae (Fabricius, 1775) The Common Rose (Atrophaneura (Pachliopta) aristolochiae) is a swallowtail butterfly belonging to the Pachliopta subgenus, the Roses, of the genus Atrophaneura or Red-bodied Swallowtails. ... Triatoma infestans is an important vector of Chagas disease, especially in the Southern Cone countries of South America; that is, in Argentina, Uruguay, Paraguay and Chile. ...

The Earth as an infrared emitter

The Earth's surface and the clouds absorb visible and invisible radiation from the sun and re-emit much of the energy as infrared back to the atmosphere. Certain substances in the atmosphere, chiefly cloud droplets and water vapor, but also carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, and chlorofluorocarbons^[17], absorb this infrared, and re-radiate it in all directions including back to Earth. Thus the greenhouse effect keeps the atmosphere and surface much warmer than if the infrared absorbers were absent from the atmosphere.^[18] This article is about Earth as a planet. ... In physics, absorption is the process by which the energy of a photon is taken up by another entity, for example, by an atom whose valence electrons make transition between two electronic energy levels. ... Sol redirects here. ... “Air” redirects here. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Methane is a chemical compound with the molecular formula CH4. ... For other uses, see Nitrous oxide (disambiguation). ... Sulfur hexafluoride is an inorganic compound with the formula SF6. ... For other uses, see CFC (disambiguation). ... Wikinews has related news: Scientists warn thawing Siberia may trigger global meltdown A schematic representation of the exchanges of energy between outer space, the Earths atmosphere, and the Earth surface. ...

History of infrared science

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The discovery of infrared radiation is ascribed to William Herschel, the astronomer, in the early 19th century. Herschel published his results in 1800 before the UK Royal Society. Herschel used a prism to refract light from the sun and detected the infrared, beyond the red part of the spectrum, through an increase in the temperature recorded on a thermometer. He was surprised at the result and called them "Calorific Rays". The term 'Infrared' did not appear until late in the 19th century. Image File history File links Broom_icon. ... For other persons named William Herschel, see William Herschel (disambiguation). ... An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ... Diagram of a triangular prism, dispersing light Lamps as seen through a prism. ... This article refers to refraction in waves. ... Sol redirects here. ... For other uses, see Red (disambiguation). ... A common mercury thermometer A thermometer is a device that measures temperature or temperature gradient, using a variety of different principles. ...

Other important dates include:^[5]

• 1835: Macedonio Melloni makes the first thermopile IR detector;
• 1859: Gustav Kirchhoff formulates the blackbody theorem E = J(T,n);
• 1873: Willoughby Smith discovers the photoconductivity of selenium;
• 1879: Stefan-Boltzmann law formulated empirically
• 1880s & 1890s: Lord Rayleigh and Wilhelm Wien both solve part of the blackbody equation, but both solutions are approximations that "blow up" out of their useful ranges. This problem was called the "UV Catastrophe and Infrared Catastrophe".
• 1901: Max Planck published the blackbody equation and theorem. He solved the problem by quantizing the allowable energy transitions.
• Early 1900s: Albert Einstein develops the theory of the photoelectric effect, determining the photon. Also William Coblentz in spectroscopy and radiometry.
• 1917: Case develops thallous sulfide detector; British develop the first infra-red search and track (IRST) in World War I and detect aircraft at a range of one mile;
• 1935: Lead salts-early missile guidance in World War II;
• 1938: Teau Ta-predicted that the pyroelectric effect could be used to detect infrared radiation.
• 1952: H. Welker discovers InSb;
• 1950s: Paul Kruse (at Honeywell) and Texas Instruments form infrared images before 1955;
• 1950s and 1960s: Nomenclature and radiometric units defined by Fred Nicodemenus, G.J. Zissis and R. Clark, Jones defines D*;
• 1958: W.D. Lawson (Royal Radar Establishment in Malvern) discovers IR detection properties of HgCdTe;
• 1958: Falcon & Sidewinder missiles developed using infrared and the first textbook on infrared sensors appears by Paul Kruse, et al.
• 1962: J. Cooper demonstrated pyroelectric detection;
• 1962: Kruse and ? Rodat advance HgCdTe; Signal Element and Linear Arrays available;
• 1965: First IR Handbook; first commercial imagers (Barnes, Agema {now part of FLIR Systems Inc.}; Richard Hudson's landmark text; F4 TRAM FLIR by Hughes; phenomenology pioneered by Fred Simmons and A.T. Stair; U.S. Army's night vision lab formed (now Night Vision and Electronic Sensors Directorate (NVESD), and Rachets develops detection, recognition and identification modeling there;
• 1970: ? Boyle & ? Smith propose CCD at Bell Labs for picture phone;
• 1972: Common module program started by NVESD;
• 1978: Pommernig & ? Francis fabricate IRCCDs; US Common Module leads to a proliferation of IR Sensors in the U.S. military; commercial IR companies formed (Inframetrics in Boston, MA and FLIR Systems Inc. in Portland OR); Infrared imaging astronomy comes of age, observatories planned, IRTF on Mauna Kea opened; 32 by 32 and 64 by 64 arrays are produced in InSb, HgCdTe and other materials.

Macedonio Melloni (April 11, 1798 &#8211; August 11, 1854) was an Italian physicist, notable for demonstrating that radiant heat has similar physical properties to those of light. ... Gustav Robert Kirchhof (March 12, 1824 – October 17, 1887) was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects. ... Willoughby Smith (April 6, 1828, Great Yarmouth, England — July 17, 1891, Eastbourne, England) was an electrical engineer who discovered the photoconductivity of the element selenium. ... For other uses, see Selenium (disambiguation). ... The Stefan-Boltzmann law, also known as Stefans law, states that the total energy radiated per unit surface area of a black body in unit time (known variously as the black-body irradiance, energy flux density, radiant flux, or the emissive power), j*, is directly proportional to the fourth... John William Strutt, 3rd Baron Rayleigh (12 November 1842 – 30 June 1919) was an English physicist who (with William Ramsay) discovered the element argon, an achievement that earned him the Nobel Prize for Physics in 1904. ... Wilhelm Carl Werner Otto Fritz Franz Wien (January 13, 1864 – August 30, 1928) was a German physicist who, in 1893, used theories about heat and electromagnetism to compose Wiens displacement law, which relates the maximum emission of a blackbody to its temperature. ... “Planck” redirects here. ... “Einstein” redirects here. ... A diagram illustrating the emission of electrons from a metal plate, requiring energy gained from an incoming photon to be more than the work function of the material. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... William Weber Coblentz (1873 &#8211; September 15, 1962) was an American physicist. ... Extremely high resolution spectrogram of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of the interaction between radiation (electromagnetic radiation, or light, as well as particle radiation) and matter. ... In telecommunication and physics, radiometry is the science of radiation measurement. ... Look up case in Wiktionary, the free dictionary. ... An infra-red search and track (IRST) system (sometimes known as infra-red sighting and tracking) is a method for detecting and tracking objects which give off infrared radiation such as jet aircraft and helicopters. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Jones may refer to: People with the surname Jones: Jones (surname) In fictional characters: Jones, a cat in 1979 film Alien by Ridley Scott and its sequel Aliens Jones, a character in George Orwells novel Nineteen Eighty-Four In companies: David Jones Limited, Australian retailing company Dow Jones & Company... This article needs cleanup. ... There are several rockets called Falcon: Falcon 1 Falcon 5 Falcon 9 AIM-4 Falcon - Air-to-air missile AIM-26 Falcon - Air-to-air missile AGM-76 Falcon - Air-to-ground missile Viper Falcon Category: ... The AIM-9 Sidewinder is a heat-seeking, short-range, air-to-air missile carried by fighter aircraft and recently, certain gunship helicopters. ... FLIR Systems was established in 1978 to pioneer the development of high-performance, low-cost infrared (thermal) imaging systems for airborne applications. ... Hughes developed the AIM-120 AMRAAM, one of the worlds most advanced air-to-air missiles Hughes Aircraft Company was a major defence/aerospace company founded by Howard Hughes. ... This article is about the philosophical movement. ... Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... The Picturephone from Pee-Wees Playhouse. ... FLIR Systems was established in 1978 to pioneer the development of high-performance, low-cost infrared (thermal) imaging systems for airborne applications. ...

See also

Look up infrared in
Wiktionary, the free dictionary.

Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... Night-vision is seeing in the dark. ... Infrared astronomy is the branch of astronomy and astrophysics which deals with objects visible in infrared (IR) radiation. ... An infrared camera, or a thermographic camera, is a device that forms an image using infrared radiation, similar to a common camera that forms an image using visible light. ... An infrared filter is a filter to remove visible light and only pass infrared light in different wavelenghts. ... Top: tree photographed in the near infrared range. ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... Infrared thermometers offer a great method for accurately and quickly measuring temperature of objects at a distance and/or in motion. ... This article is about the infrared imaging technique. ... Electromagnetic waves sent at terahertz frequencies, known as terahertz radiation, terahertz waves, terahertz light, T-rays, T-light, T-lux and THz, are in the region of the electromagnetic spectrum between 300 gigahertz (3x1011 Hz) and 3 terahertz (3x1012 Hz), corresponding to the wavelength range starting at submillimeter (<1 millimeter... Image of a small dog taken in mid-infrared (thermal) light (false-color). ... Infra-red homing refers to a guidance system which uses the infra-red light emission from a target to track it. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... A pyrgeometer is a radiometer that is sensitive to broadband thermal irradiance, in the spectral range from approximately 3. ...

References

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 300th day of the year (301st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 303rd day of the year (304th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 300th day of the year (301st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 291st day of the year (292nd in leap years) in the Gregorian calendar. ... Look up doc in Wiktionary, the free dictionary. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 311th day of the year (312th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 127th day of the year (128th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 225th day of the year (226th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st Century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ...

External links

Journals

• Infrared Physics and Technology (Elsevier) (last access June 2005).

Web sites

• List of infrared application examples broken down by industry from FLIR Systems
• Infrared Spectroscopy NASA Open Spectrum wiki site.
• IrDAOrganization that creates low cost infrared data interconnection standards.
• How to build an USB infrared receiver to remote control PCs
• Infrared WavesDetailed explanation of infrared light.
• U.S. Navy - Electronic Warfare and Radar Systems Engineering Handbook Source of transmittance diagram and further information on electro-optics.
• Infrared a Historical Perspective