The radiative-transfer theory and the Rayleigh scattering model were used to obtain the microwave brightness temperatures from dry snowpacks on the ground, which was modelled by a scattering dielectric layer and an underlying homogeneous half-space. The total radio brightness at the radiometer was the sum of the direct and diffuse radiation field intensities. The result of the model application was in good agreement with the observational data, which were obtained through the airborne experiments for the MOS-1 Verification Program around Asahikawa, Hokkaido, Japan, in February 1988.