Activities of the Russian Institute of Radionavigation and Time in development of GLONASS on-board Q-enhanced oscillating compact H-maser

The paper describes a new type of on-board atomic frequency standard developed by the Russian Institute of Radionavigation and Time (RIRT). This is Q-enhanced oscillating compact H-maser with dimensions and weight less than those of GLONASS Cs clock. The multifactor optimization of maser´s main building block construction and physical parameters has been carried out, which enabled one to lower weight of H-maser physical package down to 10 kg. The forecast enhanced performance has been obtained and attainable daily frequency stability of the H-maser comprised 10^-14. The latter is an order of magnitude higher than that of Cs clock. Reduced dimension of developed maser will allow one to substitute Cs clock by H-clock in GLONASS satellite and will provide progress in this field