Combination of WVD with TRM on detection of LFM signal in inhomogeneous medium

On the basis of time-reversal focusing theory, time frequency analysis combining with time reversal mirror (TRM) on detection of linear frequency modulation (LFM) signal in inhomogeneous medium is studied. The simulation experiment on time frequency analysis is carried out in a lab water tank. Time reversal is manifested by taking the time-domain scattered fields received on an array, reversing them, and then propagating them back into the same medium. The re-transmitted signal is received near the source and Wigner-Ville distribution (WVD) analysis is performed. The time varying spectrum of time frequency analysis gives more useful information to recognize different types of target signals. The simulation results show that the new method can suppress multi-scattering. The approach is effective and feasible.