국가 상시관측소를 활용한 스마트폰 GNSS 측위 성능 분석e)

The Android operating system's advancements have empowered smartphones to acquire raw data from GNSS (Global Navigation Satellite System), fostering active research in refining positioning precision. Smartphones, now equipped to receive dual-frequency signals (L1, L5) from Multi-GNSS, have spurred investigations into data quality, absolute and relative positioning, and hardware-driven performance enhancements. While prior studies predominantly concentrated on short-range analyses with the deployment of base stations, this research aims to address the need for user-centric analysis. Utilizing smartphones with dual-frequency capabilities, the study conducted experiments in both stationary and moving scenarios. The analysis, rooted in reference points from the National Geographic Information Institute, assesses the practicality of positioning performance using a network of observation stations spaced approximately 30 km apart across Korea. To mitigate the impact of low-quality smartphone pseudorange data, the study incorporated Doppler smoothing, resulting in a confirmed reduction of positioning errors by up to 20%. This underscores the substantial influence of Doppler smoothing in minimizing errors in smartphone data. Furthermore, based on satellite reference points, the study affirms that smartphone positioning accuracy of approximately 2-3 meters is consistently maintained throughout South Korea.