Daytime Radio Wave Scintillations in the Equatorial Electrojet Regions

219-229A study is made comparing the equatorial radio scintillations of ATS-6 signals during daytime hours at Huancayo (1974-75) and at Ootacamund (1975-76). The scintillations on VHF (137/140 MHz) band during the normal equatorial q-type of sporadic-E layer (eastward electrojet currents) are slow and weak, having 1-2 dB peak-to-peak amplitude fluctuations at Huancayo and about 5-6 dB peak-to-peak amplitude fluctuations at Ootacamund. Scintillations during the blanketing type of sporadic-B layer (westward electrojet currents) are slow but strong in amplitude exceeding 10-20 dB at either of the places. The local time variations of the daytime scintillations at Huancayo are consistently constant during any of the years within the period 1968-75. Average midday magnitude of scintillation index (SI) was 10-15% and the SI > 10% occurred more than 80% of the time in any of the years. There were no special peculiarities in VHF scintillations at Huancayo during the ATS-6 period anyway different from those during other years