RNSS Legacy Navigation Payload

Francesco Paggi*, Salvatore Corvo, Sung Soo Jang, Deok Won Lim

The core functionalities of a Navigation Satellite payloads are the generation of a stable Master Frequency Reference (MFR), to be used by payload for the coherent generation of the various navigation signals and messages, and the generation of the aforementioned navigation signals, that are broadcast by the satellite and eventually used by the user segment to determine its Position, Velocity, Time (PVT), with the required characteristics and performances. Thales Alenia Space Italia is developing the RNSS satellites Navigation SubSystem (NSS), that will provide to the whole satellite the aforementioned MFR, and generate the legacy GPS L1-L2-L5 frequencies navigation signals. This paper presents first the RNSS mission context and the main NSS design drivers; on the basis of them, the architecture of the NSS is described, together with the main technological and functional challenges and solution; in particular the NSS signal generation full digital approach will allow a complete flexibility in the signal design, allowing rapid evolutions to meet quick time-to-market constrains, as well the potential need to tune the signals’ design in the frame RNSS constellation deployment. The design of the main NSS elements is then presented, including overall preliminary signal performances.
Keywords: RNSS, PNT, navigation signal