ULTRA-ACCURATE INTERNATIONAL TIME AND FREQUENCY COMPARISON VIA AN ORBITING HYDROGEN-MASER CLOCK D.W. Allan, C.O. Alley, N. Ashby, R. Decher, R.F.C. Vessot et G.M.R. Winkler J. Phys. Colloques, 42 C8 (1981) C8-395-C8-413 DOI: 10.1051/jphyscol:1981846