Performance comparison among multi-GNSS single frequency precise point positioning techniques

Precise Point Positioning (PPP) is a technique able to compute high accuracy positioning anywhere using a single GNSS receiver and without the need for corrections from reference stations. A wide range of possible PPP algorithms, using different correction models and processing strategies, exist for both post-processing and real-time applications. PPP relies on accurate satellite and clock data, with the use of precise carrier-phase measurements. Single Frequency-PPP (SF-PPP) is currently under investigation by the scientific community, owing to its cheap implementation with respect to classical differential positioning and multi-frequency un-differenced techniques. Unfortunately, the carrier-phase observable is ambiguous by an a priori unknown integer number of cycles, called ambiguity, which is difficult to resolve with SF receivers. The aim of this paper was to study the opportunity provided by the use of a multi-GNSS constellation applied to two widespread SF-PPP models, based on different carrier-phase and code observable combinations. The algorithms were tested using static data collection carried out in an opensky scenario. The results show decimeter level accuracy on the horizontal and vertical components of the position.