Comparison and Validation of VTEC Derived from GPS, IRI-Plas and NeQuick-2 During 2015 and 2019 in India

Abstract

The paper compares Vertical Total Electron Content (VTEC) values extracted from IGS’s distributed network of dual-frequency GPS stations in India, and the VTEC values extracted through IRI-Plas-2017 and NeQuick-2.0.2 models at the same locations and the same durations of time. Diurnal variation and relative deviation of modelled and measured VTEC of IGS reference stations at Lucknow (LCK3, Latitude: 26.91218, Longitude: 80.95564) and Hyderabad (HYDE, Latitude: 17.41728, Longitude: 78.55088) are visualized through graphical representation, during 2015 and 2019. Further, statistical analysis was performed on both datasets. The outputs of this project revealed that, the magnitude of maximum relative deviation of modelled VTEC from measured VTEC was high while using IRI-Plas model at Lucknow and Hyderabad in each month of solar maximum and solar minimum. Furthermore, during solar minimum, VTEC is highly overestimated by both models during peak hours of ionization and the magnitude of overestimation at these hours is higher while using IRI-Plas model for both regions. Finally, the highest coefficient of determination value was recorded at Hyderabad during 2019 while using IRI-plas model. The R² analysis shows that IRI-Plas model produces a more accurate representation of VTEC during solar minimum and maximum at both regions.