A large number of space missions to the Moon are planned, which require accurate and reliable position, navigation and timing (PNT). There are plans for lunar satellites operating under the frame of LunaNet, which shall provide communications and PNT for orbit and surface users. Especially in an early phase, the number of satellites will be very limited. To ensure high availability and high accuracy for PNT, hybrid satellite navigation and cooperative radio navigation has been suggested. In this talk, different aspects of hybrid lunar navigation are investigated. First, we provide an estimation theoretic analysis of hybrid navigation by deriving the Bayesian Cramér-Rao bound. Second, we evaluate different distributed estimation algorithms for hybrid navigation regarding accuracy, scalability, flexibility and robustness. Third, we introduce a software-defined radio (SDR) setup for analogue experiments and provide a preliminary evaluation of measurement data.