UHF/GHz scintillation observed at Ascension Island from 1980 through 1982


  • J. P. Mullen,

  • E. MacKenzie,

  • Santimay Basu,

  • H. Whitney


Three years' scintillation measurements taken at Ascension Island have been reduced and are presented here. The 1.5-GHz and 257-MHz signals of Marisat were supplemented by 3.9-GHz observations during January–May 1981. While their temporal patterns are similar to those found earlier in the Afro-American zone, they exhibited unusually frequent occurrence of heavy scintillation at gigahertz frequencies often exceeding 30 dB at 1.5 GHz and 7 dB at 4 GHz. These patterns are attributed in part to the position of the station near the southern peak of the Appleton anomaly. Comparisons are made between these and similar observations taken at Hong Kong, near the northern peak of the anomaly.