Low-Cost Hardware PPP-RTK AR Time-to-Fix and Positioning Performance Assessment: A Preliminary Static Test

Over the last years, researchers are struggling to develop solutions and services for smart and sustainable urban mobility creating dynamic shared spaces for both vehicles and pedestrians. Also, the deployment of autonomous vehicles has boosted the interest in precise, accurate, and robust position, navigation, and timing (PNT). Most of these services will be based primarily on the location of the vehicle relative to other vehicles, objects, and pedestrians in its vicinity. Therefore, the importance of a robust, ubiquitous, and reliable PNT can’t be overlooked. In the mass-market scenario, the challenge will be developing low-cost navigation equipment capable of providing navigation solutions that meet the accuracy, integrity, continuity, and availability requirements. This paper reports some preliminary tests aiming to investigate the phase-ambiguity fixing performance of a commercial precise point positioning real-time kinematic (PPP-RTK) correction service, employing a low-cost receiver. To assess the ambiguity resolution performance, we forced the receiver to restart the ambiguity search generating enough samples for statistic analysis. In this test, PPP-RTK has revealed a promising technique for decimetre-level accuracy positioning with low-cost receivers. Integer ambiguity fixed solutions reveal a DRMS of 0.09 m whereas float solutions reveal a DRMS of 0.45 m. When PPP-RTK corrections are not available, SPP/DGNSS solutions reveal a DRMS of 1.36 m. The test showed that the employment of cost-effective equipment along with the exploitation of correction services allows reaching decimetre/sub-metre accuracy in about 20 s and sub-decimetre accuracy in about 2 min once the integer ambiguity is fixed.