Variation of Equatorial F-Region Irregularity Parameters as a Function of Solar Activity

The Air Force Geophysics Laboratory in collaboration with the Geophysical Institute of Peru and the University of Texas at Dallas performed co-ordinated measurements of nighttime F-region irregularities near the magnetic equator during 1975-1979. A variety of techniques, such as ionospheric soundings, scintillation, airglow, VHF radar backscatter and satellite in-situ density probes, were employed to study the F-region irregularities over a wide scale-length range from tens of kilometers to a few meters. The dynamics of the irregularity structures were explored by the Airborne Ionospheric Observatory on the Air Force Geophysics Laboratory as well as by the spaced receiver scintillation measurements performed on the ground. This report compiles some of these measurements with a view to studying the variation of the irregularity characteristics with changes in solar activity that occurred during the campaign periods in the years 1975-1979. (Author)