Accession Number : AD0764521

Title :   Omega Phase Variations During PCA (Polar Cap Absorption) Events: Signals Traversing the Auroral Region Exhibit Extreme Phase Variation Persisting Up to a Week or Longer During PCA'S.

Descriptive Note : Research and development May 69-Sep 70,

Corporate Author : NAVAL ELECTRONICS LAB CENTER SAN DIEGO CALIF

Personal Author(s) : Martin,J. N.

Report Date : 17 AUG 1972

Pagination or Media Count : 32

Abstract : From May 1969 to September 1970 the Omega navigation signals from Aldra, Norway, Forestport, New York, and Haiku, Hawaii were monitored at Wales, Alaska. The New York to Wales path and the Norway to Wales path traverse the auroral region and were both perturbed by 15 polar cap absorption (PCA) events which occurred during the measurement period. The data over these paths were examined to determine the importance of the PCA-induced disturbances to the Omega system. It was found that the PCA's produce extreme phase deviations persisting for times up to a week or longer and were the dominating mechanism for phase variations in Omega propagation over these paths for approximately 5 percent of the time. The phase variations were found to be highly correlated with variations in solar proton flux in the 10-30-MeV energy range. (Author)

Descriptors :   (*RADIO NAVIGATION, IONOSPHERIC DISTURBANCES), (*HYPERBOLIC NAVIGATION, VERY LOW FREQUENCY), RADIOFREQUENCY INTERFERENCE, IONOSPHERIC PROPAGATION, SOLAR DISTURBANCES, PHASE DISTORTION, HAWAII, NEW YORK, NORWAY, ALASKA

Subject Categories : Atmospheric Physics
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE