GEOMETRIC DETERMINATION OF IMPULSE ECHO RESPONSES ON SIMPLE IMMERSED TARGETS

We propose a simple interpretation of the mecanism of echo formation for targets of simple shape (spheres, cones and small tilted disks) placed far from a plane broad band transducer on its axis. This interpretation is based on the description of the radiated field in terms of plane and edge waves component. This permits to find easly the approximate shape and amplitude of the impulse response. The echo is then obtained by convolution of the latter with the excitation signal.