Comment from eLoran Technologies staff:
The big question today ‘’who invented the internet’, notwithstanding Al Gore’s claim, there is no question of who invented the ‘solid state’ Loran transmitter, at its core the innovative ‘magnetic (Loran) pulse (forming and shopping) compression technology. Dr Paul Johannessen founded the company Megapulse (1970) to exploit the technology breakthrough and apply it to the network of legacy ‘tube type’ Loran transmitters. After thorough vetting and exhaustive validation tests, 4 years in the making, the technology was approved (1974) as the technology of choice under a USCG initiative and modernization program; and mandate to provide Loran coverage and with it PNT services to the US maritime and timing communities. The mandate extended to GA with the closure of the mid continent (Loran) gap in 1986. Clearly, Paul’s achievements rest on the prior work of other, that had its beginning at the newly formed MIT radiation Lab in 1940, and recognized as a major (one of four) milestone at a recent (June 2012) IEEE Milestone in Electrical Engineering and computing awards presentation by the IEEE Boston chapter. Nevertheless Paul’s unique achievements, in the process of discovery and invention, was a major contribution to the development of a stable and reliable National Loran Network, in the US; and worldwide. Paul’s fertile mind extended the vision and applied the necessary resources to develop and to make the Loran network the terrestrial equivalent of GPS or as a backup absent GPS. Erik Johannessen, President of Megapulse accepted the honors on behalf of the Loran communities, provided the historical context in the development of the technology and spoke of the splendid collaborative effort of the many to deliver important (new) capabilities in the design and development of the ‘next generation’ eLoran PNT&C equipment and services to make Paul’s vision reality.
By Ivan Berger for IEEE.org
One breakthrough from the 19th century and three originating in 20th-century defense research were recognized in June as IEEE Milestones in Electrical Engineering and Computing.
1940 to 1946: LORAN
In October 1940, 13 months after the outbreak of World War II in Europe and 14 months before the United States entered the war, the newly formed National Defense Research Committee (NDRC) contracted with MIT to create a radio navigation system. It became one of the first three projects of MIT’s new Radiation Laboratory, commonly called the Rad Lab. The lab, which also contributed to the development of radar and the atomic bomb, became the NDRC’s largest single activity.
The LORAN (for Long Range Navigation) Division established for the project was headed by Donald G. Fink, a Fellow of IEEE’s predecessor societies, the IRE and AIEE, and later, the executive director of IEEE.
Operating in the low frequency (LF) portion of the radio spectrum, LORAN was the only non-microwave project of the Rad Lab. LORAN was a “hyperbolic navigation” system based on the difference in timing between synchronized, pulse-modulated signals received from paired radio transmitters. By measuring that difference, a navigator could determine the distance to those stations. Lacking absolute distance information, the operator knew only that the position was somewhere on a series of hyperbolic curves. Adding measurements for a second pair of stations produced a grid from which a pair of possible positions could be determined, after which other navigational techniques could resolve the ambiguity.
LORAN was based on a suggestion by IRE Fellow Alfred Lee Loomis, a wealthy inventor and physicist who helped establish the lab and arranged for its initial funding until the federal government provided money. His suggestion was a way of overcoming the range and accuracy limits of the aircraft guidance system used by Britain’s Bomber Command, codenamed GEE for “grid.” The chief researcher and scientist on the project was John Alvin “Jack“ Pierce of Harvard University. Pierce received the 1990 IEEE Medal for Engineering Excellence for his work on LORAN and other navigational systems.
The system was rapidly developed and deployed, despite the difficulties of building stations in remote areas under wartime conditions and the need for cooperation among the countries where stations were sited. The first two LORAN stations, on the U.S. Atlantic coast, were on the air by mid-1942, followed by a station in Canada. By late 1943, stations had been added in Greenland, Iceland, the Faroe Islands (between Norway and Iceland), and the Hebrides (off the west coast of Scotland). By the end of World War II, 25 stations covered the Pacific. All told, by war’s end, 70 stations were in operation, providing nighttime navigation service over 60 million square miles—about 30 percent of the earth’s surface. By 1946, 75 000 maritime and aircraft receivers had been delivered.
LORAN was crucial to the war effort, enabling navy ships and supply convoys to navigate treacherous waters, bombers to find targets, and aircraft to find their way to refueling airfields on small islands dotted across the vast Pacific, all without breaking radio silence.
LORAN also proved useful in peacetime, becoming the chief navigation system for air and maritime transport around the world until superseded by satellite-based GPS. Even today, an enhanced version, eLORAN, is being considered as a backup to GPS and other satellite navigation systems.
The plaque, installed on 27 June, adjacent to the Building 20/Radiation Laboratory memorial in the Gates Lobby of MIT’s Ray and Maria Stata Center on Vassar Street, in Cambridge, Mass., reads:
The rapid development of LORAN—long range navigation—under wartime conditions at MIT’s Radiation Lab was not only a significant engineering feat but also transformed navigation, providing the world’s first near-real-time positioning information. Beginning in June 1942, the United States Coast Guard helped develop, install, and operate LORAN until 2010.