Evaluation of BDS Navigation Signals and Positioning Performance on Android Devices

Starting with Android 7.0, Google has opened APIs for smartphone users to obtain raw GNSS data, including pseudorange, carrier, and Doppler measurements. At present, the research of Android devices positioning based on original observations mostly focuses on GPS/GLONASS/Galielo, and there is few in-depth evaluation work on the data observation quality and positioning performance of BDS. In general, compared with traditional survey-grade GNSS receivers, observations of Android devices are not only affected by high measurement noise and multipath errors, but also by abnormalities such as duty cycle and phase error accumulation. Therefore, to improve the positioning accuracy of Android smartphones, the quality of the measured data and its influencing factors must be analyzed first. This article uses the Hisilicon Hi1103 positioning chip mounted on the HUAWEI Nova5 to evaluate the data quality and positioning performance of the BDS observation in a comprehensive perspective. The carrier-to-noise ratio, duty cycle, and measurement noise of different types of BDS satellites are evaluated and statistically analyzed. In static positioning performance assessment, the accuracy of SPP and PPP using BDS is evaluated using the positioning results of the measurement receiver. While in dynamic positioning performance assessment, because the accuracy of ordinary pseudo-range single point positioning is low, the author use an improved sliding window HATCH filter algorithm, which greatly improves the accuracy of dynamic positioning.