Time-reversal multiple signal classification in case of noise: a phase-coherent approach. 
The problem of locating point-like targets beyond the classical resolution limit is revisited.  Although time-reversal MUltiple SIgnal Classification (MUSIC) is known for its super-resolution ability in localization of point scatterers, in the presence of noise this super-resolution property will easily break down.  In this paper a phase-coherent version of time-reversal MUSIC is proposed, which can overcome this fundamental limit.  The algorithm has been tested employing synthetic multiple scattering data based on the Foldy-Lax model, as well as experimental ultrasound data acquired in a water tank.  Using a limited frequency band, it was demonstrated that the phase-coherent MUSIC algorithm has the potential of giving significantly better resolved scatterer locations than standard time-reversal MUSIC.