Performance Evaluation of BDS/GPS Combined Single Point Positioning with Low-cost Single-Frequency Receiver

Low-cost global navigation satellite system (GNSS) receiver terminals are widely used in the field of navigation and location-based services due to their small size, low weight and low power consumption. For users equipped with low-cost receivers on the mass market, it is important to improve the performance of single point positioning (SPP) with single-frequency pseudorange measurement. In this study, we constructed a low-cost receiver using a single-frequency receiver module named u-blox M8T, and a compact core board named COM-IMX6UL. The receiver is capable of receiving the B1 signal of the BeiDou Navigation Satellite System (BDS) and L1 signal of the Global Positioning System (GPS). With the view of verifying the performance of single-frequency GPS/BDS single point positioning (SPP) in practice, we carried out static and vehicle-mounted kinematic experiments using the low-cost receiver and evaluated its capability based on observations and positioning results. It is demonstrated that the GPS/BDS SPP can achieve competitive satellite tracking and positioning performance compared to the GPS-only and BDS-only SPP, especially when the receiver was in a restricted environment. In the case of static experiment, the BDS/GPS SPP positioning accuracy is better than 1.5 m and 3.0 m in the horizontal and vertical directions within the cut-off angle range of 10 degrees to 35 degrees, which is a 10 similar to 30% improvement over the BDS-only SPP and a 10 similar to 60% improvement over the GPS-only SPP. In the case of the vehicle-mounted kinematic experiment, the horizontal positioning accuracy of GPS/BDS SPP is better than 1 m on urban general roads and expressways, which is approximately 50% improvement than that of GPS-only SPP.