Preprint A333/2004
Complete time-reversed refocusing in reflection with an acoustic lagrangian model
Andre Nachbin | Alfaro, Daniel | Correia, Adolfo
Keywords: Scattering of acoustic waves | acoustic time-reversal | Numerical schemes
This work presents discrete reflection-transmission acoustic models through which numerical experiments are performed efficiently. Each model is expressed through its corresponding reflection-transmission matrix and their connections with the continuous acoustic model are discussed in detail. Important physical phenomena are studied computationally. In particular reflection-transmission properties of waves in a rapidly varying random medim, which are valid over long propagation distances. By using a long computational domain, in a regime where we have Anderson localization, the energy of an incoherently scattered signal is entirely reflected back and, by time-reversal, completely recompressed into the smooth initial data. Another new result is the time-reversed refocusing, in reflection, of a wave train in the form of a bit stream. The robustness of the time-reversed refocusing phenomenon is outstanding.