Dual- and Triple-Frequency GNSS Ambiguity Resolution for High-Precision Spaceborne Relative Navigation

Kurzfassung

Centimeter-level relative navigation is a critical enabler for emerging multi-spacecraft missions requiring precise inter-spacecraft geometry. This capability supports a wide range of applications, including high-resolution Earth observation with SAR interferometric constellations, autonomous rendezvous and on-orbit servicing, distributed aperture telescopes for astrophysics, atmospheric and magnetospheric science swarms, and geodetic or gravimetric missions demanding long-term orbital stability. This work investigates dual- and triple-frequency GNSS carrier-phase ambiguity resolution within a real-time Kalman filter for high-precision relative navigation. Using TerraSARX/TanDEM-X datasets, wide- and narrow-lane strategies are evaluated to quantify accuracy and reliability improvements. Results show that while dual-frequency methods achieve satisfactory performance with temporal averaging, triple-frequency processing significantly enhances ambiguity-fixing success and reduces positioning errors. The study demonstrates that triple-frequency GNSS significantly increases the robustness and precision of real-time relative navigation, enabling future formation-flying and distributed-spacecraft missions.