Abstract:
The paper reports night time observations of ionospheric irregularities made through amplitude scintillation of
251 MHz signal at Kolhapur (16.4 N, 74.2 E), an equatorial Appleton anomaly region using spaced antenna
system. Monthly and night time percentage of occurrence of scintillations, during increasing solar cycle from
January 2011 to August 2015, is discussed. The parameters such as-maximum cross-correlation function (CI),
Fade Rate are also studied. The percentage occurrence is observed to be higher in post sunset period and during
equinoctial months than in winter and summer months. Scintillation occurrence is observed to be suppressed
during increasing solar activity. CI shows seasonal changes. Percentage of occurrence of CI 0.5 decreases with
increase in solar activity and fade rate also shows solar activity dependence.
