Imaging of underground interface using impulse ultrasound and amplitude correlation synthesis processing method

An interface scanning method is proposed for imaging of underground interfaces, such as during the exploration of comparatively large archaeological sites or the interfaces of different earth layers. The path lengths of ultrasonic waves from the sound source to each receiver corresponding to an interface to be calculated are derived according to the shortest path propagating principle. The corresponding amplitudes and polarities are derived from signals of each channel. The image magnitude of the interface to be calculated can then be calculated by the amplitude correlation synthesis processing method. The compared imaging results of an underground interface derived by the previous point scanning method and by the interface scanning method using both the numerical simulation and experiments are presented. The interfaces with different angles of declination are imaged clearly by the interface scanning method while only a blurred image at the center of the interface is obtained by the point scanning method.