Investigation of Ionospheric Total Electron Content (TEC) During Summer Months for Ionosphere Modeling in Indian Region Using Dual-Frequency NavIC System

Abstract

AbstractWhen signals from satellites propagate through the ionosphere, a delay is introduced due to the presence of Total Electron Content (TEC) between transmitter and receiver. The generation of TEC in the ionosphere is primarily dependent on solar activity (Diurnal and Seasonal). The ionospheric delay can cause a major degradation in the positional accuracy of the satellite navigation system. For the estimation of ionospheric delay, slant TEC (STEC) along the path between satellite and receiver is needed. For a single-frequency user, a modeled ionospheric vertical TEC (VTEC) at Ionospheric Pierce Point (IPP) is converted into STEC for delay estimation. However, the behavior of TEC is highly dynamic in low-latitude and equatorial regions (Indian region), and thus conventional ionospheric model introduces additional error in positioning. The NavIC (Navigation with Indian Constellation) system geostationary satellite constellation is uniquely capable of the investigation of ionospheric TEC, and it can facilitate for ionospheric modeling applications. This paper deals with estimating of accurate STEC and VTEC using dual-frequency NavIC code and carrier measurements, and investigation of its temporal variation for modeling applications. KeywordsTotal Electron Content (TEC)STECVTECIonospheric delayNavICIonospheric modeling