LEO Augmentation in Large-Scale Ionosphere-Float PPP-RTK Positioning

• DOI: 10.1061/jsued2.sueng-1414
• Publication Date: 2024-01-04T15:53:12Z
• Authors: Kan Wang; Ahmed El-Mowafy; Fang Cheng; Xuhai Yang
• Keywords: Precise Point Positioning; Ambiguity Resolution; Real Time Kinematic; Float (project management)

Precise point positioning-real-time kinematic (PPP-RTK) positioning combines the advantages of PPP and RTK, which enables integer ambiguity resolution (IAR) without requiring a reference station nearby. The ionospheric corrections are delivered to users enable fast IAR. For large-scale networks, precise interpolation delays is challenging. often independently estimated by user, in so-called ionosphere-float mode. augmentation low Earth orbit (LEO) satellites can bridge this shortcoming thanks their speeds resulting rapid geometry change. Using 30-s real dual-frequency Global Positioning System (GPS) Beidou Navigation Satellite (BDS) observations within network thousands kilometers, contribution tests effects LEO using simulated signals from navigation-oriented constellation, CentiSpace. Results showed that makes solution convergence less sensitive original (GNSS)-based model strength. improvements times significant. example, mode, time 90% lines GPS/BDS-combined ambiguity-float horizontal solutions 0.05 m shortened more than 60 3.5 min, GPS-only partial (PAR)-enabled 20 4.5 min. In both PAR-enabled cases, 68.27% (1σ) static height errors converge 4 for lines, 6.5 min all cases. line GPS/BDS/LEO combined 2.5 3 up direction, respectively. also enlarged projection mismodeled biases on user coordinates were observed LEO-augmented scenario after or resolution. This mainly due lower orbital elevation angles satellites, requires further research when navigation available.