Everett Tim, Taylor Trey, Lee Dong-Kyeong, Akos Dennis M
RTK Consultants LLC, Niwot, CO 80503, USA.
Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO 80309, USA.
Sensors (Basel). 2022 May 18;22(10):3825. doi: 10.3390/s22103825.
The Google Smartphone Decimeter Challenge (GSDC) was a competition held in 2021, where data from a variety of instruments useful for determining a phone's position (signals from GPS satellites, accelerometer readings, gyroscope readings, etc.) using Android smartphones were provided to be processed/assessed in regard to the most accurate determination of the longitude and latitude of user positions. One of the tools that can be utilized to process the GNSS measurements is RTKLIB. RTKLIB is an open-source GNSS processing software tool that can be used with the GNSS measurements, including code, carrier, and doppler measurements, to provide real-time kinematic (RTK), precise point positioning (PPP), and post-processed kinematic (PPK) solutions. In the GSDC, we focused on the PPK capabilities of RTKLIB, as the challenge only required post-processing of past data. Although PPK positioning is expected to provide sub-meter level accuracies, the lower quality of the Android measurements compared to geodetic receivers makes this performance difficult to achieve consistently. Another latent issue is that the original RTKLIB created by Tomoji Takasu is aimed at commercial GNSS receivers rather than smartphones. Therefore, the performance of the original RTKLIB for the GSDC is limited. Consequently, adjustments to both the code-base and the default settings are suggested. When implemented, these changes allowed RTKLIB processing to score 5th place, based on the performance submissions of the prior GSDC competition. Detailed information on what was changed, and the steps to replicate the final results, are presented in the paper. Moreover, the updated code-base, with all the implemented changes, is provided in the public repository. This paper outlines a procedure to optimize the use of RTKLIB for Android smartphone measurements, highlighting the changes needed given the low-quality measurements from the mobile phone platform (relative to the survey grade GNSS receiver), which can be used as a basis point for further optimization for future GSDC competitions.
谷歌智能手机分米挑战赛（GSDC）是2021年举办的一场竞赛，比赛提供了来自各种仪器的数据，这些数据可用于使用安卓智能手机确定手机位置（GPS卫星信号、加速度计读数、陀螺仪读数等），以便对用户位置的经度和纬度进行最精确的测定，并对其进行处理/评估。可用于处理GNSS测量的工具之一是RTKLIB。RTKLIB是一款开源的GNSS处理软件工具，可与GNSS测量数据（包括码、载波和多普勒测量数据）一起使用，以提供实时动态（RTK）、精密单点定位（PPP）和后处理动态（PPK）解决方案。在GSDC中，我们专注于RTKLIB的PPK功能，因为该挑战赛只需要对过去的数据进行后处理。尽管PPK定位预计能提供亚米级的精度，但与大地测量接收机相比，安卓测量数据质量较低，使得这种性能难以持续实现。另一个潜在问题是，Tomoji Takasu创建的原始RTKLIB是针对商业GNSS接收机而非智能手机的。因此，原始RTKLIB在GSDC中的性能有限。因此，建议对代码库和默认设置进行调整。实施这些更改后，根据之前GSDC竞赛的性能提交情况，RTKLIB处理获得了第五名。本文介绍了所做更改的详细信息以及复制最终结果的步骤。此外，公共存储库中提供了包含所有已实施更改在内的更新代码库。本文概述了一种优化RTKLIB用于安卓智能手机测量的程序，强调了鉴于手机平台测量质量较低（相对于测量级GNSS接收机）所需的更改，这些更改可作为未来GSDC竞赛进一步优化的基点。
