Performance Analysis of BDS Single-Epoch Triple-Frequency Vehicle-Borne RTK under Complex Urban Scenarios

Vehicle-borne positioning in urban environments is a crucial application scenario of the BeiDou Real-Time Kinematic (RTK) technique. However, its performance is often affected by signal interruptions and ambiguity resolution failures. The integration of BeiDou-3 (BDS-3) and BeiDou-2 (BDS-2) will significantly increase the number of available satellites with improved ambiguity resolution, thereby enhancing high-precision positioning performance in complex urban environments. In this work, a vehicle-borne experiment with collected triple-frequency observations from BDS-2 and BDS-3 satellites were utilized to evaluate the ambiguity resolution and positioning performance of single-epoch triple-frequency RTK positioning in urban environments. The results indicate that in complex urban environments, the extra-wide-lane ambiguity of certain satellites cannot be correctly resolved by the integer rounding methods. The centimeter-level positional availability of BDS-2 alone is relatively low, whereas the ambiguity resolution success rate and centimeter-level positional availability are significantly improved when BDS-2 and BDS-3 signals are integrated.