Pulsed beam pre- and post-processing for localized inverse scattering

Well‐collimated short pulse wave packets, also termed pulsed beams (PB), provide new options for local forward and inverse probing of targets or of a propagation environment. The spatial‐temporal resolution achieved under the PB excitation conditions furnishes an unambiguous measure of where the ‘‘physical’’ signal resides, in contrast to frequency‐domain procedures that must rely on more intricate phase discrimination. In this paper, PB forward and inverse modeling is applied to scattering by three‐dimensional weak (Born‐type) inhomogeneities with finite support in an otherwise homogeneous background fluid. By performing space–time and wave number–frequency analysis and synthesis in a phase space setting, conventional slant‐stack tomography is pushed to its ultimate localization by PB pre‐ and post‐processing. The implications of this scenario with respect to resolution and related issues are discussed. It is shown that this strategy reduces the inversion of the illuminated space‐time scattering cell to a pseudo‐one‐dimensional problem determined by the orientation of the incident and scattered beam axes. Illustrative examples are included.