Passive array imaging in random media
For researchers in acoustic imaging and remote sensing, it offers a method to enhance resolution in random media, though it is an incremental improvement over existing CINT techniques.
The paper presents an algorithm for high-resolution imaging of sound sources in random scattering media, improving upon coherent interferometry (CINT) to resolve sources too close for CINT alone. Numerical simulations demonstrate its performance.
We present a novel algorithm for high resolution coherent imaging of sound sources in random scattering media using time resolved measurements of the acoustic pressure at an array of receivers. The sound waves travel a long distance between the sources and receivers so that they are significantly affected by scattering in the random medium. We model the scattering effects by large random wavefront distortions, but the results extend to stronger effects, as long as the waves retain some coherence i.e., before the onset of wave diffusion. It is known that scattering in random media can be mitigated in imaging using coherent interferometry (CINT). This method introduces a statistical stabilization in the image formation, at the cost of image blur. We show how to modify the CINT method in order to image wave sources that are too close to each other to be distinguished by CINT alone. We introduce the algorithm from first principles and demonstrate its performance with numerical simulations.