Assessing the Positional Accuracy of Raw GNSS Data From Android Devices

Smartphone devices have become the focus of attention of scholars dealing with GNSS measurements since May 2016 when Google stated using Android operating system version N that can access GNSS raw data. This opened the research door wide to process this data and analyse different issues in positioning by smartphones. Our study contributes to the assessment of GNSS data accuracy by evaluating various Android Application Programs (APPS) using Samsung Galaxy S9PLUS smartphone. While previous research has explored this topic, our study distinguishes itself through a comprehensive comparison of three APPS and two positioning techniques. By highlighting performance variations and considering multiple constellations, we provide valuable insights for smartphone GNSS users. Three different Apps were utilised: G-RitZ Logger, GnssLogger, and rinex ON. In addition, two GNSS positioning techniques were used for assessment: Post Processing Static (PPS) and Precise Point Positioning (PPP). The results revealed that GnssLogger obtain consistent readings in different scenarios. Therefore, GnssLogger is considered as the best logging GNSS data by smartphones. Moreover, accuracy is also discussed based on different constellations: GPS, GLONASS, and GALILEO. As expected, GPS results are the best compared to other constellations owing to availability and tracking priority for smartphone software. The best results obtained from GnssLogger with PPS technique and GPS system which has given RMS as 0.034 m, 0.171 m, and 0.383 m for E-W, N-S, and U-D axes respectively.