Snapshot time t = 480 μs, for the radiation pattern of a point force directed along x₁, and located at 5.5 cm from the center of a Luneburg lens with a radius of 5 cm based in the center of a field of 50 cm by 50 cm, with a frequency of 25 kHz (a), 35 kHz (b) and 30kHz (c); morphing result (d) between (a) and (b), (e) is (c) transformed in a grayscale image, (f) is (d) transformed in a grayscale image and (g) is the absolute value of the difference between (e) and (f).