Editing Forward-looking infrared

{{Short description|Type of thermographic camera}}
{{redirect|FLIR|the company|FLIR Systems|the UFO video|Pentagon UFO videos}}
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[[File:NAVFLIR DAMOCLES P1220870.jpg|thumb|250px|A [[Thales Group|Thales]] [[Damocles (targeting pod)|Damocles]] FLIR targeting pod]]
'''Forward-looking infrared''' ('''FLIR''') cameras, typically used on military and civilian aircraft, use a [[thermographic camera]] that senses [[infrared radiation]].<ref>{{cite web |url=http://www.cerdec.army.mil/inside_cerdec/nvesd/ |archive-url=https://web.archive.org/web/20141004201753/http://www.cerdec.army.mil/inside_cerdec/nvesd/ |url-status=dead |archive-date=2014-10-04 |title=Night Vision & Electronic Sensors Directorate |publisher=US Army CERDEC |access-date=2014-04-24 }}</ref>

The sensors installed in forward-looking infrared cameras, as well as those of other thermal imaging cameras, use detection of infrared radiation, typically emitted from a [[heat]] source ([[thermal radiation]]), to create an image assembled for [[video]] output.

They can be used to help [[Aviator|pilots]] and drivers steer their vehicles at night and in fog, or to detect warm objects against a cooler background. The [[wavelength]] of infrared that thermal imaging cameras detect is 3 to 12&nbsp;[[micrometre|μm]] and differs significantly from that of [[night vision]], which operates in the visible light and [[near-infrared]] ranges (0.4 to 1.0 &nbsp;μm).

== Design ==
[[File:Flickr - Official U.S. Navy Imagery - Alleged drug traffickers are arrested by Colombian naval forces..jpg|thumb|300px|FLIR imagery from a U.S. Navy helicopter: Alleged drug traffickers are being arrested by Colombian naval forces.]]

[[infrared|Infrared light]] falls into two basic ranges: ''long-wave'' and ''medium-wave''. Long-wave infrared (LWIR) cameras, sometimes called "far-infrared", operate at 8 to 12&nbsp;μm and can see heat sources, such as hot engine parts or human [[body heat]], several kilometers away. Longer-distance viewing is made more difficult with LWIR because the infrared light is [[absorption (optics)|absorbed]], [[scattering|scattered]], and [[refraction|refracted]] by air and by water vapor.

Some long-wave cameras require their detector to be [[cryogenics|cryogenically]] cooled, typically for several minutes before use, although some moderately sensitive infrared cameras do not require this. Many thermal imagers, including some forward-looking infrared cameras (such as some LWIR [[Synthetic vision system|enhanced vision systems]] (EVS)) are also uncooled.

''Medium-wave'' (MWIR) cameras operate in the 3–5&nbsp;μm range. These can see almost as well, since those frequencies are less affected by water-vapor absorption, but generally require a more expensive [[sensor array]], along with cryogenic cooling.

Many camera systems use [[digital image processing]] to improve the image quality. Infrared imaging sensor arrays often have wildly inconsistent sensitivities from [[pixel]] to pixel, due to limitations in the manufacturing process. To remedy this, the response of each pixel is measured at the factory, and a transform, most often linear, maps the measured input signal to an output level.

Some companies offer advanced "fusion" technologies that blend a visible-spectrum image with an infrared-spectrum image to produce better results than a single-spectrum image alone.<ref>{{cite web |url=http://www.sri.com/newsroom/videos/topic/273 |title=Three-Band Video Fusion Demo : Sarnoff Corporation |date=May 2008 |publisher=Sarnoff.com |access-date=2011-11-24}}</ref>

==Properties==
Thermal imaging cameras such as the Raytheon AN/AAQ-26 are used in a variety of applications, including [[naval vessels]], fixed-wing [[aircraft]], [[helicopter]]s, [[armored fighting vehicle]]s, and military-grade [[smartphones]].<ref>{{cite news |title=Blackview BV9800 Pro Featuring FLIR Lepton Thermal Camera Available Now |url=https://www.flir.com/news-center/press-releases/blackview-bv9800-pro-featuring-flir-lepton-thermal-camera-available-now/ |access-date=March 12, 2022 |agency=Teledyne |date=January 7, 2020}}</ref>

In warfare, they have three distinct advantages over other imaging technologies:
# The imager itself is nearly impossible to detect for the enemy, as it detects energy emitted from the target rather than sending out energy that is reflected from the target, as with [[radar]] or [[sonar]].
# It sees radiation in the infrared spectrum, which is difficult to [[camouflage]].
# These camera systems can see through smoke, fog, haze, and other atmospheric obscurants better than a [[visible light]] camera can.

==Etymology==
The term "forward-looking" is used to distinguish fixed forward-looking thermal imaging systems from sideways-tracking infrared systems, also known as "[[Push broom scanner|push broom]]" imagers, and other thermal imaging systems such as gimbal-mounted imaging systems, handheld imaging systems, and the like. Pushbroom systems typically have been used on aircraft and satellites.

Sideways-tracking imagers normally involve a one-dimensional (1D) array of pixels, which uses the motion of the aircraft or satellite to move the view of the 1D array across the ground to build up a 2D image over time. Such systems cannot be used for real-time imaging and must look perpendicular to the direction of travel.

==History==
In 1956, [[Texas Instruments]] began research on [[infrared]] technology that led to several line scanner contracts and, with the addition of a second scan mirror, the invention of the first forward-looking infrared camera occurred in 1963, with production beginning in 1966. In 1972, TI introduced the Common Module concept, which greatly reduced costs and allowed for the reuse of common components.

== Uses==
[[File:FLIR monté sur Eurocopter AS350 Écureuil AS-555 Fennec de l'Armée de l'Air.jpg|thumb|200px|A FLIR pod on a French Air Force helicopter]]
[[File:FLIR used during search and rescue operation.jpg|thumb|200px|A FLIR system on a U.S. Air Force helicopter during search and rescue operation]]
*Traffic video detection and monitoring<ref>https://www.flirmedia.com/MMC/CVS/Traffic/IT_0002_EN.pdf {{Bare URL PDF|date=March 2022}}</ref> 
*[[Surveillance]] and/or capture of [[mammals]]
**Detection of [[Illegal immigration|illegal immigrants]] hidden in lorries/trucks
**Warning drivers about sudden road obstructions caused by deer
**Location through smoke and/or haze
*[[Search and rescue]] operations for missing persons especially in wooded areas or water
*Target acquisition and tracking by military or civil [[aircraft]]
*[[Drainage basin]] temperature monitoring<ref>{{cite journal|title=Multiscale thermal refugia and stream habitat associations|journal=Ecological Applications |volume=9|pages=301|doi=10.1890/1051-0761(1999)009[0301:MTRASH]2.0.CO;2|issn=1051-0761|year=1999}}</ref> and monitoring wild game habitats
*Detection of energy loss or consumption, or [[Thermal insulation|insulation]] defects
**Mapping insulation levels (pipes, walls, joints etc.) in order to reduce [[HVAC]] energy consumption
**Quality control for especially electrical installations (a picture can reveal if loads are higher than expected, or show bad and potentially failing joints)
**Search for drug labs and/or indoor [[Cannabis (drug)|cannabis]] producers (especially at night)
*Piloting of aircraft in low visibility ([[Instrument Meteorological Conditions|IMC]]) conditions
*Pinpoint sources of ignition during [[firefighting]] operations
*Monitoring active volcanoes
*Detecting faulty or overheating electrical joints, connections, and components
*Night driving
*Identification or visual acquirement of hostile ground vehicles or personnel

== Cost ==

The cost of thermal imaging equipment in general has fallen dramatically after inexpensive portable and fixed infrared detectors and systems based on [[microelectromechanical systems|microelectromechanical technology]] were designed and manufactured for commercial, industrial, and military application.<ref>Niklaus, F., Vieider, C., & Jakobsen, H. (2007, November). [https://www.researchgate.net/profile/Henrik_Jakobsen/publication/229039574_MEMS-Based_Uncooled_Infrared_Bolometer_ArraysA_Review/links/0912f511b8aa6ee228000000.pdf MEMS-based uncooled infrared bolometer arrays: a review]. proceedings of [[SPIE]] - The International Society For Optical Engineering, March 2008.</ref><ref>[https://spie.org/Documents/ConferencesExhibitions/DSS15-Abstracts-lr.pdf Infrared Technology and Applications XLI, 20–23 April 2015, Part of Proceedings of SPIE, Vol. 9451.]</ref><ref>Dr. Don Reago, Director, Night Vision & Electronic Sensors Directorate, CERDEC, U.S. Army. [http://www.cerdec.army.mil/news_and_media/Owning_the_Environment_Current_trajectory_in_Army_visual_sensors/Dr_Reago_SPIE_keynote.pdf Current Directions in Sensor Technologies at NVESD] {{Webarchive|url=https://web.archive.org/web/20160304130640/http://www.cerdec.army.mil/news_and_media/Owning_the_Environment_Current_trajectory_in_Army_visual_sensors/Dr_Reago_SPIE_keynote.pdf |date=2016-03-04 }}, Keynote Presentation at [[SPIE]] DSS IR Technology & Applications XLI Conference, Baltimore, 20–23 April 2015 (Distribution Statement A: Approved for Public Release)</ref> Also, older camera designs used rotating mirrors to scan the image to a small sensor. More modern cameras no longer use this method; the simplification helps reduce cost. Uncooled technology available in many [[Enhanced_flight_vision_system | Enhanced Flight Vision System]] (EFVS or EVS) products have reduced the costs to fractions of the price of older cooled technology, with similar performance.<ref>
  Willardson, R. K., Weber, E. R., Skatrud, D. D., & Kruse, P. W. (1997). [https://books.google.com/books?id=5zXS_By-nQ8C&dq=advances+uncooled+infrared&pg=PP2 Uncooled infrared imaging arrays and systems (Vol. 47).] Academic press.</ref>
<ref>
  [http://www.sofradir-ec.com/wp-uncooled-detectors-achieve.asp White Paper: Uncooled Infrared Detectors Achieve New Performance Levels and Cost Targets], 
  {{
     Webarchive
       | url=https://web.archive.org/web/20151207213325/http://www.sofradir-ec.com/wp-uncooled-detectors-achieve.asp
       | date=2015-12-07
  }}
  Sofradir EC, Inc.
</ref>
EVS is rapidly becoming mainstream on many fixed wing and rotary wing operators from [[Cirrus Aircraft|Cirrus]] and [[Cessna]] aircraft to large business jets.

== Police actions ==
In 2001, the [[United States Supreme Court]] decided in ''[[Kyllo v. United States]]'' that performing surveillance of private property (ostensibly to detect high emission [[grow light]]s used in clandestine cannabis farming) using thermal imaging cameras without a [[search warrant]] by law enforcement violates the [[Fourth Amendment to the United States Constitution|Fourth Amendment's]] protection from unreasonable searches and seizures.<ref>{{cite web|url=https://www.law.cornell.edu/supct/html/99-8508.ZS.html |title=KYLLO V. UNITED STATES (99-8508) 533 U.S. 27 (2001) 190 F.3d 1041, reversed and remanded.|publisher=Law.cornell.edu |access-date=2008-12-11}}</ref>

In the 2004 ''[[R. v. Tessling]]'' judgment,<ref>{{Cite web |url=http://scc.lexum.org/en/2004/2004scc67/2004scc67.html |title=R v Tessling, (2004) 3 S.C.R. 432, 2004 SCC 67 |access-date=2011-04-06 |archive-url=https://web.archive.org/web/20120403173920/http://scc.lexum.org/en/2004/2004scc67/2004scc67.html |archive-date=2012-04-03 |url-status=dead }}</ref> the [[Supreme Court of Canada]] determined that the use of [[Bombardier Dash-8|airborne FLIR in surveillance by police]] was permitted without requiring a search warrant. The Court determined that the general nature of the data gathered by FLIR did not reveal personal information of the occupants and therefore was not in violation of Tessling's Section 8 rights afforded under the [[Charter of Rights and Freedoms]] (1982). [[Ian Binnie]] distinguished the Canadian law with respect to the Kyllo judgment, by agreeing with the Kyllo minority that public officials should not have to avert their senses or their equipment from detecting emissions in the public domain such as excessive heat, traces of smoke, suspicious odors, odorless gases, airborne particulates, or radioactive emissions, any of which could identify hazards to the community.

In June 2014, the Canadian National Aerial Surveillance Program DHC-8M-100 aircraft mounted with [[infrared sensor]]s was instrumental in the search for [[Justin Bourque]], a fugitive who had killed three [[Royal Canadian Mounted Police]] members in [[Moncton]]. The plane's crew used its advanced heat-sensing camera to discover Bourque's heat signature in the deep brushwoods at midnight.<ref>[http://www.ctvnews.ca/canada/funeral-for-3-fallen-rcmp-officers-to-be-held-tuesday-in-moncton-1.1857807 ctvnews.ca: "Funeral for 3 fallen RCMP officers to be held Tuesday in Moncton" 7 Jun 2014]</ref>

During [[2015 Baltimore protests]], the [[Federal Bureau of Investigation|FBI]] conducted 10 aerial surveillance missions between April 29 and May 3, which included "infrared and day color, full-motion FLIR video evidence" collection, according to FBI spokesman Christopher Allen.<ref name="TALON">[https://www.washingtonpost.com/news/the-switch/wp/2015/10/30/fbi-spy-planes-used-thermal-imaging-tech-in-flights-over-baltimore-after-freddie-gray-unrest/ FBI spy planes used thermal imaging tech in flights over Baltimore after Freddie Gray unrest], The Washington Post, October 30, 2015</ref> A FLIR Talon multi-sensor camera system equipped with an infrared laser pointer (which is invisible to casual observers) for illumination purposes was used to gather data at night.<ref>[http://www.flir.com/surveillance/display/?id=64172 Talon High Performance Multi-Sensor]</ref> The [[American Civil Liberties Union]] raised concerns over the fact that new surveillance technology is implemented without judicial guidance and public discussion.<ref>[https://www.aclu.org/blog/free-future/fbi-documents-reveal-new-information-baltimore-surveillance-flights FBI Documents Reveal New Information on Baltimore Surveillance Flights], ACLU, October 30, 2015</ref> According to Nathan Wessler, an ACLU attorney, "this is a dynamic we see again and again when it comes to advances in surveillance. By the time details leak out, programs are firmly entrenched, and it's all but impossible to roll them back – and very hard to put in place restrictions and oversight."<ref name="TALON" />

==See also==
* [[Automotive night vision]]
* [[Electro-optical targeting system]]
* [[Infra-red search and track]]

== References ==
{{reflist}}

== External links ==
{{Commons category|FLIR}}
* [http://www.ausairpower.net/TE-EO-Systems.html Electro-Optical Systems]
* [https://web.archive.org/web/20070904211645/http://ausairpower.net/NCW-101-6.pdf Thermal Imaging Sensors (Defence Today)]
* [http://www.aviationtoday.com/rw/public-service/police/Essential-Equipment-Reach-of-FLIR-Surges-Forward_82549.html Comparison Chart] {{Webarchive|url=https://web.archive.org/web/20150923021844/http://www.aviationtoday.com/rw/public-service/police/Essential-Equipment-Reach-of-FLIR-Surges-Forward_82549.html |date=2015-09-23 }}

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[[Category:Infrared imaging]]
[[Category:Military electronics]]
[[Category:Night flying]]
[[Category:Night vision devices]]
[[Category:Targeting (warfare)]]
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