G. F. Sage

Peer Reviewed

Abstract: THE MARK III SYSTEM was designed to demonstrate real time airborne Omega as a practical reality. The results as reported in a FAA Horizon article are: During a 7,500 nautical mile flight the MARK III Omega system “demonstrated absolute superiority over all other navigation methods available on board the test aircraft, including Loran A, Loran C and celestial. During one period of more than four hours, precipitation static knocked out all of the aircraft’s Loran and voice communications, but had no effect on Omega availability and accuracy.” This paper describes the MARK III operation and configuration. The MARK III was designed and built jointly by NRL and Lear Siegler. The system operates on frequencies of 10.2 and 1133 kHz. Either carrier or the difference frequency may be used. Phase measurement is accomplished in the computer by mathematical operations on the sampled IF signals. The flexibility and power of the general purpose computer allow the execution of complex signal processing functions which would be impractical for analog or special purpose digital equipment. The svstem operates in an airborne environment u&g a DR sensor for rate aiding. The computer converts the received phase to lat,itude and longit,ude and computes navigation parameters. Included are the results of extensive flight tests. The operation of the system was demonstrated by flight, tests conducted by NRL. Data was gathered during 150 hours of flight tests to Europe, Trinidad, Bermuda, Hawaii and over the continental United States. The estimated system accuracy was that expected for the Omega system of 1 mile during daytime and 2 miles at night. There was no signal loss due to weather conditions.
Published in: NAVIGATION, Journal of the Institute of Navigation, Volume 16, Number 4
Pages: 371 - 381
Cite this article: Sage, G. F., "NRL-LSl MARK III AIRBORNE OMEGA SYSTEM", NAVIGATION, Journal of The Institute of Navigation, Vol. 16, No. 4, Winter 1969-1970, pp. 371-381.
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