Abstract: An IEM surface scattering model was examined in terms of its applicability to simulations and laboratory measurements. New expressions for both single scattering and multiple scattering were obtained by re‐deriving the scattering coefficient to keep all the phase terms in the spectral representation of Green's function. After quite intricate mathematical manipulations, a fairly compact form for an advanced IEM model (AIEM) is obtained for the scattering coefficients. In addition, the Fresnel reflection coefficients used in the model were replaced by a transition function. The comparisons in this paper were concentrated in the case of backscattering with both numerical simulations and measurement data. The results indicate that the IEM is improved, becoming more accurate and practical to use.