We propose a set of experiments in which Ramsey-fringe techniques aretailored to probe transitions originating and terminating on the same groundstate level. When pulses of resonant radiation, separated by a time delay $% T,$ interact with atoms, it is possible to produce Ramsey fringes having widthsof order 1/T. If each pulse contains two counterpropagating travelling wavemodes, the atomic wave function is split into two or more components havingdifferent center-of-mass momenta. Matter-wave interference of these componentsleads to atomic gratings, which have been observed in both spatially separatedfields and time separated fields. Time-dependent signals can be transformedinto frequency dependent signals, leading to ground state Ramsey fringes(GSRF). The signals can be used to probe many problems of fundamentalimportance: a precise measurement of the earth gravitational acceleration $g$and residual gravity in a microgravity environment with an accuracy $610^{-9}g;$ the rotation rate measurement with an accuracy of 6 10^{-3} deg/h;the recoil frequency measurement. Since only transitions originating and terminating on the same ground stateare involved, frequency measurements can be carried out using lasersphase-locked by quartz oscillators having relatively low frequency. Ourtechnique may allow one to increase the precision by a factor of 100 (the rf-to quartz oscillator frequencies ratio) over previous experiments based onRaman-Ramsey fringes or reduce on the same factor requirements for frequencystabilization.
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