In this paper we report on the MEM power spectrum analysis of brightness temperature fluctuations observed at 2.8 GHz during the total solar eclipse of 16 February 1980. The observed periodicities range from 3.5 min to 64 min. These periodicities may arise due to spatial and/or temporal variations in the solar radio emission. The observed periodicities imply presence of scale sizes ranging from 70,000 to 600,000 km assuming that the brightness fluctuations arise because of spatial variation only. On the other hand, if these fluctuations are due to temporal variation, the observed periodicities correspond well to predicted modes of solar global oscillations.

Angular displacements in the positions of the quasar 3C 298 were observed during its interplanetary scintillation (ips) observations made using a correlation interferometer at 103 MHz at Thaltej near Ahmedabad. These changes in the apparent positions of the source could be seen as variations in the declination of 3C 298. Two possibilities which might cause such effects are considered; refraction of the radio waves either in the earth’s ionosphere or in the interplanetary medium (ipm) by large scale plasma density inhomogeneities. Order of magnitude calculations for both are presented. Further studies using two-site observations are suggested to decide between the two mechanisms.