An account on the development of a directional microphone system for jet‐noise‐source strength distribution measurements is given. The system selected is based on the imaging principle of a spherical concave reflector. As expected, the system is diffraction limited; a loss of resolution results. A special technique is discussed to recover the axial‐source strength distribution from the diffracted data. Sample experiments are presented to show the successful application of such a system for jet noise measurements.Subject Classification: [43]28.65; [43]50.55; [43]85.62.