Nassat completes high-precision PPP-RTK GNSS-SSR solution
Nassat has completed the development of a high-precision positioning solution based on PPP-RTK with state space representation (GNSS-SSR). The advance integrates global state estimation and phase ambiguity resolution to enable precise real-time positioning. The PPP-RTK approach combines the robustness of PPP with the rapid convergence characteristic of RTK, without relying on station-to-user differences. The SSR representation transmits system error models — rather than differential observations — preserving the geodetic consistency of the corrections. In this architecture, the GNSS state components are modelled and updated explicitly. The SSR channel encapsulates temporally aligned correction information, suitable for recursive estimation at the receiver. The solution prioritises: internal model consistency and traceability; integer phase ambiguity resolution to stabilise position; and functional separation between the state generator and the client engine. The pipeline incorporates strict temporal synchronisation and integrity management through statistical quality controls. The treatment of atmospheric delays is addressed with parametric models consistent with the SSR paradigm, allowing the use of multi-frequency carriers with bias control. With this milestone, Nassat consolidates a technical line based on explicit error modelling and precise real-time positioning, preparing the architecture for operational integration in accordance with the requirements of each project.
NASSAT - Network Satellite Systems