Research on Triple-Frequency Dual-Ionosphere-Free Combination PPP Based on PPP-B2b Service

<div class="section abstract"><div class="htmlview paragraph">The recent public release of the PPP-B2b service, along with advancements in multi-frequency and multi-GNSS systems, has opened up significant new opportunities for the development of Precise Point Positioning (PPP) technology. Utilizing the precise orbit and clock corrections provided by PPP-B2b and the increasing availability of multi-frequency signals, this paper introduces a novel tri-frequency, dual ionosphere-free PPP model based on PPP-B2b services. The model is designed with twelve unique tri-frequency combinations, tailored to various frequency choices, combination methodologies, and single/dual GNSS systems. Results from static positioning experiments indicate that the BDS-only tri-frequency dual ionosphere-free model offers substantial improvements over traditional models. Specifically, it achieves approximately a 25% increase in vertical accuracy and reduces convergence time by around 30% when compared to the BDS-only tri-frequency undifferenced uncombined model. This demonstrates the model's potential to enhance performance under static conditions. For dynamic positioning, the model proves equally effective. The four BDS-only tri-frequency dual ionosphere-free combinations show accuracy in the E and U directions comparable to that of the BDS-only four-frequency undifferenced uncombined model. However, in the N direction, the tri-frequency dual ionosphere-free combinations reach an average accuracy of 0.010m, which represents an approximate 40% improvement over the 0.017m achieved by the four-frequency undifferenced uncombined model. Additionally, these combinations reduce convergence time by about 30%.When GPS is incorporated, the dual-system tri-frequency combination offers even more benefits. Both in dynamic and static scenarios, the dual-system approach improves convergence time by 20% to 40% compared to single-system positioning, while also achieving slightly higher positioning accuracy. These findings underscore the effectiveness of the PPP-B2b service in optimizing PPP applications for both static and dynamic use cases.</div></div>