A PPP-RTK single-base-station positioning service method for space-ground fusion

To address the high-precision positioning requirements for autonomous unmanned aerial vehicle (UAV) inspection by the State Grid in areas without public network coverage, existing technologies such as network real-time kinematic positioning (NRTK), precise point positioning-real-time kinematic (PPP-RTK) and conventional single-base-station RTK exhibited limitations including dependence on public networks, slow convergence, terminal incompatibility, and high deployment costs. Thus, a space-ground fusion PPP-RTK single-base-station positioning service method is proposed. The approach integrates the advantages of satellite-based communication and ground-based PPP-RTK techniques. It broadcasts wide-area state space representation (SSR) parameters via communication satellites to achieve rapid ambiguity resolution for the PPP-RTK single-base-station, and then disseminates observation space representation (OSR) parameters to ensure compatibility with existing RTK terminals. Experimental results demonstrate that in static scenarios, the average convergence time for the PPP-RTK single-base-station is 144.6 s, with RMS of broadcast errors of 0.9 cm, 1.5 cm, and 3.9 cm in the east (E), north (N), and up (U) directions, respectively. 95% of the horizontal and vertical broadcast errors are within 4 cm and 7 cm. In dynamic scenarios, after excluding environmental obstructions, the RMS of positioning errors for RTK terminals are 1.8 cm, 3.7 cm, and 5.4 cm in the E, N, and U directions. The proposed method operates without public network support, enables rapid deployment, and offers a novel solution for high-precision positioning in power systems.