Evaluation of Seasonal Variability of First-Order Ionospheric Delay Correction at L5 and S1 Frequencies Using Dual-Frequency NavIC System

For the precise positioning applications it is important to determine and eliminate error introduced by various sources such as ionosphere. To develop a standalone navigation system, India has launched seven satellite constellations for NavIC (Navigation with Indian Constellation) system which can provide precision over surrounded landmass. Since ionospheric delay depends on frequency of signal systems work at different frequencies L5 S1 than Global Positioning System (GPS) L1 L2, not possible use GPS data-driven study based location calculations directly. Thus there need specialized systems. In addition, directly proportional Slant Total Electron Content (STEC) dependent upon diurnal seasonal solar activity. achieve accurate facilities, also evaluation variability correction receivers. This paper deals STEC estimation; it's smoothing, removal instrumental biases from STEC. The determined true been used first-order frequencies. found less (2–7 m) compared (10–30 m). Furthermore, analyzed using about 19 months data (from June 2017 December 2018) that follows unique characteristics be utilized modeling. It observed geostationary satellites are more appropriate geosynchronous related studies.