The evaluation of IRNSS/NavIC system’s performance in its primary and secondary service areas–data quality, usability and single point positioning

Abstract

The Navigation with Indian Constellation (NavIC), also known as Indian regional navigation satellite system, is a regional navigation satellite system recently developed by India. Its service area covers from 30°E to 130°E and from 30°S to 50°N. In this contribution, an assessment of NavIC from aspects of data quality, usability and single point positioning (SPP) performance is carried out using real measured data collected from four sites both within NavIC’s primary and secondary service areas. Data quality of NavIC’s signal is assessed measuring its carrier-to-noise-density ratio and each satellite’s orbital period is calculated using its broadcast ephemeris. Visible satellite number and DOPs values of each site in modes of NavIC-only, GPS-only and GPS/NavIC are counted and calculated respectively. SPP solutions in modes of NavIC-only, GPS-only and GPS/NavIC are also carried out for these four sites. The results show that: the signal strength of NavIC’s L5 frequency generally equals that of GPS in site IISC (Fig. 1); mean orbital periods of IGSO and GEO satellites are 86160.70 s and 86152.03 s respectively; in site IISC (within the primary service area), currently NavIC system can provide an independent positioning service with an accuracy of less than 1 m in the east direction and less than 2 m in north and up directions respectively; the usability and SPP performance can be improved significantly in the mode of GPS/NavIC compared with those in either single mode.