Editing Lidar (section)

== History and etymology ==

The essential concept of lidar was originated by [[Edward Hutchinson Synge|E. H. Synge]] in 1930, who envisaged the use of powerful searchlights to probe the atmosphere.<ref>''Philosophical Magazine and Journal of Science'', 1930, series&nbsp;7, volume&nbsp;9, issue&nbsp;60, pp.&nbsp;1014–1020.</ref><ref>Donegan, J. F.; ''[https://www.livingedition.at/en/isbn/9783901585173/ The Life and Works of Edward Hutchinson Synge]'', pp.&nbsp;31, 67, (co-edited with D.&nbsp;Weaire and [[Petros Serghiou Florides|P.&nbsp;Florides]]), Pöllauberg, Austria : Living Edition, {{ISBN|3-901585-17-6}}.</ref>

Under the direction of Malcolm Stitch, the [[Hughes Aircraft Company]] introduced the first lidar-like system in 1961,<ref>{{cite news |title=New Radar System |work=Odessa American |date=28 Feb 1961}}</ref><ref name="Macomber">{{cite news |last1=Macomber |first1=Frank |title=Space Experts Seek Harness for Powerful LASER Light |url=https://www.newspaperarchive.com/us/california/bakersfield/bakersfield-californian/1963/06-03/page-5/ |access-date=11 July 2019 |work=Bakersfield Californian |agency=Copley News Service |issue=5 |date=June 3, 1963}}</ref> shortly after the invention of the laser. Intended for satellite tracking, this system combined laser-focused imaging with the ability to calculate distances by measuring the time for a signal to return using appropriate sensors and data acquisition electronics. It was originally called "Colidar" an acronym for "coherent light detecting and ranging",<ref name="stitch">{{cite journal |first1=M. L. |last1=Stitch |first2=E. J. |last2=Woodburry |first3=J H. |last3=Morse |title=Optical ranging system uses laser transmitter |journal=Electronics |date=21 April 1961 |volume=34 |pages=51–53}}</ref> derived from the term "[[radar]]", itself an acronym for "radio detection and ranging". All{{citation needed|date=November 2023}} laser [[Rangefinding telemeter|rangefinder]]s, laser altimeters and lidar units are derived from the early colidar systems.

The first practical terrestrial application of a colidar system was the "Colidar Mark II", a large rifle-like laser rangefinder produced in 1963, which had a range of 11&nbsp;km and an accuracy of 4.5 m, to be used for military targeting.<ref>{{cite news |title=Laser Measures Distance |work=Lincoln Journal Star |issue=6 |date=29 March 1963}}</ref><ref name="Macomber" /> The first mention of lidar as a stand-alone word in 1963 suggests that it originated as a portmanteau of "[[light]]" and "radar": "Eventually the laser may provide an extremely sensitive detector of particular wavelengths from distant objects. Meanwhile, it is being used to study the Moon by 'lidar' (light radar)&nbsp;..."<ref name="James Ring p. 672-3">James Ring, "The Laser in Astronomy", pp.&nbsp;672–673, ''New Scientist'', June 20, 1963.</ref><ref name=Oxford>{{cite book |title=Oxford English Dictionary |year=2013 |page=Entry for "lidar" |url=http://www.oed.com/}}</ref>
The name "[[photonic radar]]" is sometimes used to mean visible-spectrum range finding like lidar.<ref name="auto2">{{Cite web |url=https://www.technion.ac.il/en/2016/05/19138/ |title=Photonic Radar |website=Technion – Israel Institute of Technology |date=27 May 2016 |access-date=2018-08-12}}</ref><ref name="auto1">{{Cite web |url=http://fullafterburner.weebly.com/next-gen-weapons/radio-optic-phased-array-radar-a-comprehensive-study |title=Radio Optic Phased Array Radar – a comprehensive study |website=Full Afterburner |access-date=2018-08-12}}</ref>

Lidar's first applications were in meteorology, for which the [[National Center for Atmospheric Research]] used it to measure [[clouds]] and pollution.<ref name=Goyer>{{cite journal |last=Goyer |first=G. G. |author2=R. Watson |title=The Laser and its Application to Meteorology |journal=Bulletin of the American Meteorological Society |date=September 1963 |volume=44 |issue=9 |pages=564–575 [568] |doi=10.1175/1520-0477-44.9.564 |bibcode=1963BAMS...44..564G |doi-access=free}}</ref> The general public became aware of the accuracy and usefulness of lidar systems in 1971 during the [[Apollo&nbsp;15]] mission, when astronauts used a laser altimeter to map the surface of the Moon.
Although the English language no longer treats "radar" as an acronym, (i.e., uncapitalized), the word "lidar" was capitalized as "LIDAR" or "LiDAR" in some publications beginning in the 1980s. No consensus exists on capitalization. Various publications refer to lidar as "LIDAR", "LiDAR", "LIDaR", or "Lidar". The [[USGS]] uses both "LIDAR" and "lidar", sometimes in the same document;<ref>{{cite web |url=http://lidar.cr.usgs.gov/ |title=CLICK |website=Lidar.cr.usgs.gov |date=2015-09-16 |access-date=2016-02-22 |archive-url=https://web.archive.org/web/20160219045753/http://lidar.cr.usgs.gov/ |archive-date=2016-02-19 }}</ref> the ''[[New York Times]]'' predominantly uses "lidar" for staff-written articles,<ref>{{cite web |url=https://query.nytimes.com/search/sitesearch/?action=click&contentCollection=Science&region=TopBar&WT.nav=searchWidget&module=SearchSubmit&pgtype=article#/lidar/since1851/document_type%3A%22article%22/ |title=NYTimes.com search |website=[[The New York Times]] |access-date=2017-04-07}}</ref> although contributing news feeds such as [[Reuters]] may use Lidar.<ref>{{cite web |url=https://www.nytimes.com/reuters/2017/03/29/technology/29reuters-uber-tech-alphabet-lawsuit.html |title=Waymo Self-Driving Unit Sought Arbitration Over Engineer Now at Uber |website=[[The New York Times]] |date=2017-03-29 |access-date=2017-04-07}}</ref>