Case Study: Performance Observation of NavIC Ionodelay and Positioning Accuracy

Abstract

The NavIC is an Indian satellite based navigation system uses the L5 and S-band signals to provide 10 m (metres) and 0.1 m positioning accuracy services for civilian and military users respectively. The positioning accuracy of the NavIC system is affected by many sources of error, and the ionospheric delay (Ionodelay) error is the dominant error in all. We observed the NavIC L5 band Iono delay and positioning accuracy under the influence of the intense geomagnetic storm (D st = −124, KP = 8) that occurred on 8 September 2017 at various geographical locations. Here, the NavIC S band is explored to observe the impact of geomagnetic storm (8 September 2017) and the performance is compare with NavIC L5 band at the low-latitude SVNIT Surat station (21.16° N, 72.78° E) for the second week of September 2016, 2017 and 2018. To observe the impacts of seasonal variation on the NavIC L5 and S band Ionodelay is also measured for the days of June 2016 to May 2017. It has been observed that in the days of the Summer season and an intense geomagnetic stormy day (8 September 2017) NavIC performance has faced challenges for positioning accuracy. It has been also observed the compare to NavIC L5 band S band faced more challenges for positioning accuracy. After correcting the ionosphere, troposphere, clock, and other deviations, the average ∼70% NavIC positioning accuracy is improved for the overall observed duration, conditions, and locations.