Editing Semi-Automatic Ground Environment (section)

===Project Lincoln===
Loomis took over direction of Project Lincoln and began planning by following the lead of the earlier RadLab. By September 1951, only months after the Charles report, Project Lincoln had more than 300 employees. By the end of the summer of 1952 this had risen to 1300, and after another year, 1800. The only building suitable for classified work at that point was Building 22, suitable for a few hundred people at most, although some relief was found by moving the non-classified portions of the project, administration and similar, to Building 20. But this was clearly insufficient space. After considering a variety of suitable locations, a site at [[Hanscom Air Force Base|Laurence G. Hanscom Field]] was selected, with the groundbreaking taking place in 1951.<ref name=charles/>

The terms of the [[National Security Act of 1947|National Security Act]] were formulated during 1947, leading to the creation of the US Air Force out of the former [[US Army Air Force]]. During April of the same year,  US Air Force staff were identifying specifically the requirement for the creation of automatic equipment for radar-detection which would relay information to an air defence control system, a system which would function without the inclusion of persons for its operation.<ref name="Kent C. Redmond"/> The December 1949 "Air Defense Systems Engineering Committee" led by Dr. [[George Valley]] had recommended computerized networking<ref name="Quarterly Progress Report"/> for "radar stations guarding the northern air approaches to the United States"<ref name="web.mit.edu"/> (e.g., in Canada). <!--In 1949 the USAF had funded [[Project Charles]] to develop a demonstration system for automating Air Defense{{Citation needed|date=July 2011}}--> After a January 1950 meeting, Valley and [[Jay Forrester]] proposed using the [[Whirlwind I]] (completed 1951) for air defense.<ref>{{cite web | url=https://www.technologyreview.com/2015/06/23/167538/the-many-careers-of-jay-forrester/ | title=The Many Careers of Jay Forrester }}</ref> On August 18, 1950, when the "[[1954 Interceptor]]" requirements were issued, the USAF "noted that manual techniques of aircraft warning and control would impose "intolerable" delays"<ref name=Futrell>{{Cite report |last=Futrell |first=Robert Frank |date=June 1971 |title=Ideas, Concepts, Doctrine: A History of Basic Thinking in the United States Air Force 1907–1964 |volume=1 |publisher=Aerospace Studies Institute, Air University}} (cited by Volume I p. 187)</ref>{{rp|484}} ([[Air Materiel Command]] (AMC) published ''Electronic Air Defense Environment for 1954'' in December <!--1950-->.)<ref name=McRee>{{Cite report |last=McRee |first={{Who|reason=McRee's first name needs specified.|date=April 2013}}|date=15 December 1950 |title=…Electronic Air Defense Environment for 1954 |publisher=Headquarters, Air Materiel Command}}</ref>  During February–August 1951 at the new [[Lincoln Laboratory]], the USAF conducted [[Project Claude]] which concluded an improved air defense system was needed.{{Citation needed|reason=data from Lincoln Lab article|date=July 2011}}
[[File:Texas Tower 4.jpg|thumb|250px|right|To increase warning time, radar systems called [[Texas Towers]] were placed in the Atlantic Ocean using technology similar to Texas-style offshore oil platforms]]
In a test for the US military at [[Bedford, Massachusetts]] on 20 April 1951, data produced by a radar was transmitted through telephone lines to a computer for the first time, showing the detection of a mock enemy aircraft. This first test was directed by [[C. Robert Wieser]].<ref name="Kent C. Redmond">{{cite book |url=https://books.google.com/books?id=dxZVbxcf_IoC |author1=Kent C. Redmond  |author2=Thomas M. Smith |name-list-style=amp |title=From Whirlwind to MITRE: The R&D Story of the SAGE Air Defense Computer|publisher=[[MIT Press]] |year=2000 |isbn=978-0-262-26426-6}}(''20th of April 1951'' - p.1, ''National Security Act 1947'' - p.12, ''April 1947'' - p.13)</ref>

The "Summer Study Group" of scientists in 1952 recommended "computerized air direction centers…to be ready by 1954."<ref>{{Cite news |last1=Lapp |last2=Alsop |date=March 21, 1953 |title=We Can Smash the Red A-Bombers |newspaper=Saturday Evening Post |page=19}} (citation 29 of Volume I, p. 25)</ref>

[[International Business Machines|IBM]]'s "Project High" assisted under their October 1952 Whirlwind subcontract with [[Lincoln Laboratory]],{{r|Pugh}}{{rp|210}} and a 1952 USAF [[Project Lincoln]] "fullscale study" of "a large scale integrated ground control system" resulted in the SAGE approval<!--Schaffel p. 207--> "first on a trial basis in 1953".{{r|VolumeI}}{{rp|128}}  The USAF had decided by April 10, 1953, to cancel the competing [[Wizard Program|ADIS]]<!--Schaffel p. 199--> (based on CDS), and the University of Michigan's [[Aeronautical Research Center]] withdrew in the spring.{{r|RedmondSmith}}{{rp|289}} [[Air Research and Development Command]] (ARDC) planned to "finalize a production contract for the Lincoln Transition System".{{r|Schaffel}}{{rp|201}}  Similarly, the July 22, 1953, report by the [[Harold H. Bull|Bull Committee]] ([[United States National Security Council|NSC]] 159) identified completing the [[Mid-Canada Line]] radars as the top priority and "on a second-priority-basis: the Lincoln automated system"<ref>quote from Schaffel p. 191; Condit p. 259 footnote 1 cites: "''CCS 381 US (5-23-46) sec 37.''"</ref>  (the decision to control Bomarc with the automated system was also in 1953.)<ref>{{Cite report |last=McVeigh |first=D. R. |date=January 1956 |title=The Development of the Bomarc Guided Missile 1950–1953 |publisher=Western Air Development Center}} (cited by Volume I p. 108 footnote 69: "''Before the end of 1953, it was also decided that the Sage system being developed by Lincoln Laboratories would be used to control the Bomarc.<sup>69</sup>''")</ref>

The Priority Permanent System with the initial (priority) radar stations was completed in 1952{{r|Schaffel}}{{rp|223}} as a "manual air defense system"<!-- (Col John Morton)--><ref name=IYD/> (e.g., [[North American Aerospace Defense Command|NORAD]]/[[Air Defense Command|ADC]] used a "[[Plexiglas]] plotting board" at the [[Ent Air Force Base|Ent command center]].)<!--{{r|Schaffel}}{{rp|151}}-->  The [[Permanent System radar stations]] included 3 subsequent phases of deployments and by June 30, 1957, had 119 "Fixed CONUS" radars, 29 "Gap-filler low altitude" radars, and 23 control centers".{{r|Condit}}  At "the end of 1957, ADC operated 182 radar stations [and] [[Manual Air Defense Control Center|17 control centers]] … 32 [stations] had been added during the last half of the year as low-altitude, unmanned gap-filler radars.  The total consisted of 47 gap-filler stations, 75 Permanent System radars, 39 semimobile radars, 19 [[Pinetree Line|Pinetree stations]],…1 [[Lashup Radar Network|Lashup -era radar]] and a single [[Texas Tower]]".{{r|Schaffel}}{{rp|223}}  "On 31 December 1958, USAF ADC had 187 operational land-based radar stations" (74 were "P-sites", 29 "M-sites", 13 "SM-sites", & 68 "[[Zone of Interior|ZI]] Gap Fillers").{{r|NORAD1958B}}