Comparison of backscattering of short pulses by solid spheres and cylinders at large k a

Abstract

Backscattering measurements from solid aluminum spheres and cylinders have been performed at large ka using short ultrasonic pulses. A geometrical theory is developed in order to calculate the arrival times and the amplitudes of the echoes. The theoretical arrival times are the same for a sphere and cylinder of the same material and same radius, but there are important differences in the echo amplitudes. A focusing effect which prevents geometrical analysis is predicted for one type of echo from the sphere. The experimental arrival times for spheres and cylinders of the same radius are compared, and the echo amplitudes at different ranges and target sizes are compared with theory. Very good agreement is obtained between theory and experiment.