The backscattered peak intensity, $\mid{In}\mid$ of soda-lime glass with roughness from 5.31 ㎛ to 10.38 ㎛ showed a linear dependence as
$$\mid{I_N}\mid = -4.247h(㎛) + 89.593$$
The theory about backward propagating leaky wave proposed by Norris [1] was modified to explain the backscattered peak phenomenon and compared with six material covering.
ε from 0.207 to 0.759. The observed amplitude of backward propagating leakyRayleigh wave generated was proportional to $\exp[-3.07\varepsilon^2]$ which was in fair agreement with present theory. Backscattered peak phenomenon was mainly controlled by the radiation and the scattering of the leaky-Rayleigh wave generated. The proportion of the radiation and the scattering varied with $\varepsilon$.