Oceanographic radar timing stability required for new ITU spectral allocations

New international frequency bands have been allocated to oceanographic radar use. This poses major challenges that are reviewed in this paper. Because large national networks of coastal radars must output data continuously in real time, modulation multiplexing of the commonly used FMCW signals is the only known solution. This imposes requirements for frequency stability and synchronization of one part in 10¹⁰. The analysis behind this is reviewed here. Fortunately, stability to this level is possible based on several available techniques.