Experimental investigation of the detection and location of a target in layered media by using the TR-RTM mixed method

Targets in layered media can be detected and located using a time reversal (TR)-reversed-time migration (RTM) mixed method. In this study, this single emission-multiple receiving method is tested experimentally by using two types of layered media and three types of targets. The signal reflected at the interface and the signal scattered by the target are measured by each receiver to obtain the travel time for several transmitter-receiver pairs. Thereafter, the amplitude ratio between the two measured signals is compared with the theoretical amplitude. The RTM process involves the convolution of the forward acoustic beam from the source with the backward acoustic beam from the receiver which adds an appropriate delay determined on the measured travel time data. By using this approach, the acoustic field distribution can be obtained, and the position of the target can be determined. Moreover, the measured positions of the target are compared with the actual position to validate the accuracy of this technique.