Adaptation of a GNSS open-source receiver for analysis of LEO-PNT scenarios

With the advent of the first Low Earth Orbit (LEO) mega-constellations, the concept of Low Earth Orbit for Position, Navigation, and Timing (LEO-PNT) has become a hot topic in the Global Navigation Satellite Systems (GNSS) community. In this context, this paper provides a description of the required modifications applied to an open-source GNSS software receiver to work properly under LEO dynamics. In addition, a set of key indications is given to adapt a GNSS simulator to generate a LEO-PNT scenario. Finally, a comparison of the end-to-end performance between GNSS and LEO-PNT is analyzed through a case example, which illustrates the benefits of properly adapting the tracking strategy to each scenario.