Super-resolution in time-reversal focusing on a moving source

•Analysis of time-reversal refocusing on a moving source.•Quantification of super-resolution effects.•Comparison of subsonic and supersonic regimes.

This paper presents a detailed analysis of time-reversal experiments involving a moving point source that emits a pulse. Different configurations are addressed with full-aperture or partial-aperture time-reversal mirrors and with subsonic or supersonic sources. Doppler effects and lack of source-receiver reciprocity significantly affect the time-reversal refocusing when the velocity of the source becomes comparable as or larger than the speed of propagation. The main result is that refocusing can be enhanced when the velocity of the source becomes close to the speed of propagation compared to the classical diffraction-limited refocusing properties when the source does not move, and this super-resolution effect can be quantified by simple and explicit formulas.