73 



SIJPPLEMEST I / 49 



Box II.2 

 Origins of the Global Positioning System 



The global positioning system (GPS), a satellite-based system enabling remarkably precise 

 pinpointing of one's location on Eanh, is a contemporary product of a diverse R&D system. 

 GPS evolved from postwar work on atomic clocks to test aspects of general relativity theor>'. 

 TTieir possible value for navigation was recognized by the military, which provided years of 

 "patient federal capital" to mature the technolog)-. >XTiile the military's primary interest in 

 what was to become GPS was to improve the delivery of tactical weapons and to reverse the 

 proliferation of costly new navigation systems, its civilian potential was seen at the outset; that 

 is. earl>' in its development GPS was recognized as a potential dual-use technology, and in fact 

 the commercial GPS market now overshadows military' demand.' 



Several military programs involved in what was to become GPS coalesced in 1972, when 

 the Air Force was given responsibilirv' for developing a navigation system for all military ser- 

 vices as well as civilian users. Concurrently, technologies essential to GPS, including satellites 

 and microelectronics, also were being developed. Experimental GPS satellites were launched 

 in 19~8, and proof that GPS could be used for locating one's place on Eanh soon followed. 

 Eighteen GPS satellites were launched by the United States by 1990. Today's system consists of 

 24 satellites, each carrying up to four atomic clocks that provide timing and ranging signals. A 

 GPS receiver decodes the signals to determine and displa>' their latitude, longitude, and alti- 

 tude. Differential (IPS is the most widely used method for augmenting basic GPS signals and 

 now yields centimeter accuracies over distances of several kilometers. That translates into 

 what is already an incredible array of applications, such as demonstrating new systems for 

 landing aircnih in bad weather (i.e. .a fully automatic GAT II aircraft landing); robotic plowing, 

 planting, and fertilizing of fields; monitoring train locations; and tracking and cleaning up oil 

 spills The 199S global GPS market is estimated at $2.3 billion today and is projected to reach 

 S 1 1 .6 billion Vi\ 2()()() ' Civil production of GPS units is now more than 70,000 per month. 



Secretary of Defense William I. Perr\ recently commented that the "GPS system . . . was the 

 ke\ to being able to find and rescue Capt. Scott O'Grady (the Air Force pilot shot down June 2 



and rescuedjunc 8. 199^1 and pull him out of Bosnia That whole operation would not have 



been possible except for the fact that Capt. 0'(jrady had a little GPS receiver on his wrist and 

 the incoming helicopters had a receiver. . .The consequence — they landed essentially at his 

 feet, and the total time on the ground was less than two minutes. If they had had to spend a 

 half hour or so searching for him. the results could have been very different."* 



'National Acadciin ot I'lihliL Administration. Tlw Global Positioning System: Charting the Future (Wash- 

 ington, ox: National Acadcnn of Public Administration. 199'i), pp. 5, 14. 

 •National Acudcnn ol Public Administration, The Global Positioning System. 1995, p. IS. 

 'Prepared remarks ot Sccretan. of Defense William .1 Pcrr>' to the Economics Engineering Systems Depan- 

 mcnt graduating class. Stanford Univcrsin-. Stanford, Calif, June 18. 1995. 



architectures. The Decade ot the Brain, a 10-year federal commitment to exploit the 

 ad\ ances ot many facets of brain research conducted through multiple departments 

 and agencies, is iniierentiy interdisciplinary The program has several specific goals 

 that cncompa,ss diverse areas of science, and it incorporates a ■wide range of tech- 

 nologies used in brain imaging, molecular genetics, and computer analysis of com- 

 plex biological structures." 



25-681 0-96-4 



