Investigation of Ionospheric Scintillations and Total Electron Content (TEC) over Mid-latitudinal Region (Pakistan)

摘要

The ionosphere is a medium of free moving electrons where the presence of irregularities (electron density) may cause rapid fluctuations in the phase and/or amplitude of the received GPS signals also known as ionospheric scintillation which may result in reduced performance of the satellite-based navigation systems such as GPS, GLONASS, Galileo etc. This paper studies the occurrence of ionospheric scintillation and TEC variations over Pakistan using real-time GPS signals by installing Septentrio PolaRx5s GNSS receiver at Sukkur IBA University (27.73° N, 68.82° $E$). The study uses the data collected during the month of February and March 2019. The main objective of this paper is to study the scintillation effects on GPS receivers through loss of lock and carrier-to-noise ratio in relationship to TEC variations over Pakistan for the first time. The need for this study arises as Pakistan is located at mid-latitudes and, there are only very few scintillation studies exists for mid-latitude regions and hence this paper will help in understanding the scintillation morphology over Pakistan. The initial study on scintillation presented in this paper suggests that the navigational receivers at mid-latitudes (Pakistan) are more likely to be affected by amplitude scintillation due to high values as compared to the phase scintillation. This can be problematic for the high precision applications such as aviations industry because amplitude scintillation affects the signal-to-noise ratio (SNR) of the signal and therefore signal quality.