GPS Total Electron Content (TEC) estimation using single station measurements

Global Positioning System (GPS) operates in the microwave band, for which ionosphere is a dispersive medium and has a frequency-dependent effect on the signals. This effect can be used to gather vital information about the ionosphere itself in terms of the Vertical Total Electron Content (vTEC). This is an important parameter since ionosphere error is perhaps the largest source of error in the GPS PVT solutions. Predicting the effect of ionosphere is not a simple task since it varies daily, yearly, seasonally and also according to the sunspot cycle. This study presents the results of daily TEC variability over the mid-latitude region of Islamabad (33.52o N, 33.18o E) in a quite ionosphere period. The measurements from a dual frequency receiver were processed and statistically analyzed to observe the local development and temporal variation of Total Electron Content (TEC) from both range and phase. It is possible to extend the same methodology to other geographical regions of interest. The aim of this study is to set a reference trend for TEC variability that will help characterize any abnormal ionospheric activity in this region for future. The research shows that the vTEC value peaks around mid-day and the maximum vTEC obtained is 15 TECU which causes a positioning error of up to 2.4m).