Disclosed is a method and apparatus for precisely measuring the position of moving atoms in an atom beam. The method employs atomic resonance imaging in which a spatially varying potential correlates an atomic resonance frequency with the atomic position. The method comprises (a) emptying an atomic beams of all atoms in a predetermined detectable final state; (b) passing the atomic beam through a field which induces atoms in the beam to make a transition from the initial atomic state to the detectable final atomic state, while simultaneously providing a spatially varying potential and wherein the energy of the final atomic state of the atoms is dependent upon the position of the atoms in the spatially varying potential concurrent with the field; and (c) detecting the final atomic state of said atoms to generate a spectrum which corresponds to the position distribution of atoms in the atomic beam. Apparatus for implementing said method of measuring moving atoms is also disclosed.