LEO-Augmented UDUC PPP-RTK for Faster Wide-Area Convergence

The patent introduces LEO satellites as an intermediary component between ground-based GNSS receivers and the ionosphere. LEO satellites carry ionospheric total electron content (TEC) measurements from multiple ground stations, acting as mobile intermediaries that deliver ionospheric correction information to users in wide-area regions where traditional ground station networks are sparse. This mediator approach enables users to obtain ionospheric corrections without relying solely on local ground stations or performing complex ionosphere-float modeling, thus reducing convergence time while maintaining positioning flexibility.

The patent transitions from a two-dimensional ground-based ionospheric correction network to a three-dimensional space-based correction system by deploying LEO satellites. This dimensional change allows ionospheric corrections to be delivered from space to ground users, expanding the coverage area and enabling users in remote or wide-area regions to access ionospheric corrections that would otherwise be unavailable, thereby reducing convergence time without sacrificing positioning adaptability.

LEO satellites serve as mobile intermediaries that collect ionospheric TEC measurements from multiple ground stations and relay them to users in orbit or to ground receivers. This intermediary approach allows the system to achieve accurate ionospheric corrections without requiring a dense, fixed ground station network, thereby reducing system complexity and cost while maintaining or improving ionospheric delay accuracy through the satellite's ability to traverse multiple ground stations and gather diverse measurements.

The patent changes the spatial and temporal parameters of ionospheric measurement collection by using LEO satellites. Instead of relying on a static ground station network with fixed spatial distribution, the satellite-based system dynamically samples the ionosphere along its orbital path, collecting TEC measurements at different locations and times. This parameter change enables accurate ionospheric modeling with fewer ground stations, reducing network complexity while maintaining measurement precision.

The patent merges LEO satellite observation equations with traditional GNSS UDUC PPP-RTK observation equations into a unified integrated observation model. By combining the measurement equations from both LEO and GNSS systems, the patent creates a synergistic model that leverages the complementary strengths of both satellite types. The LEO observations provide additional geometric diversity and ionospheric sampling, accelerating convergence, while the unified equation structure manages complexity through systematic integration rather than separate processing.

The integrated observation equation serves multiple functions simultaneously: it processes both GNSS and LEO satellite measurements, estimates user position, resolves carrier-phase ambiguities, and models ionospheric delays. This multi-functional observation model eliminates the need for separate processing chains for different satellite systems, managing complexity through a universal framework that handles diverse measurements and objectives in a unified mathematical structure, thereby achieving rapid convergence without proportionally increasing operational complexity.