Assessing NavIC Accuracy at Dehradun in the Winter Season: A Case Study

The aim of this research paper is to evaluate the performance of the Indian Regional Navigation Satellite System (NavIC) in the low latitude northern region of India during December 2019 observing low elevation angles (below 50°) of most of the NavIC satellites. The study includes an analysis of statistical methods to analyze positional variability of NavIC receiver, and found out its impact on the calculation of circular error probability (CEP) using a statistical approach. The study was conducted by collecting data from a NavIC receiver located in the low latitude northern region of India during December 2019. The results showed that the CEP was within acceptable limits for most of the time, but occasional outliers were observed due to the low elevation of the satellites. When low-elevation satellite observations produce outliers in the NavIC system, the CEP calculation can become inaccurate due to signal blockages, interference, or environmental factors that influence position estimation precision. The consequences of occasional outliers in the CEP calculation can be significant, particularly for applications that require high precision location data. The study suggests that more research is needed to enhance the accuracy of the NavIC system in situations where the satellites are at a low elevation angle and there are strong ionospheric irregularities or ionospheric scintillations.