Observation of planetary waves as seen in Ionospheric Total Electron Content (TEC) perturbation using GISTM Pontianak

In this study, the planetary waves as seen in ionospheric total electron content (TEC) perturbation were observed by GISTM (GPS Lonospheric Scintillation and TEC Monitoring) at Pontianak (-0.03 , 109.33 ") during the beginning maximum solar activity period 2011. Analysis periodicities of the VTEC time series have been done by using a Fast Fourier Transform (FFT).Results show the presence of the strong oscillations I day.This could be related to planetary waves type oscillations (10 and 16 days) with possible influence of the half solar rotation period (13.5 days) After the daily oscillations were removed the VTEC time series was examined by the power spectral density (PSD) There are two periodic components, quasi 10 day and quasi periodic 2 day Quasi 10 day strong occur in the October dan April, while quasi 2 day weakly occur in September.