This paper explores a new set of indoor radar scattering measurements system from terrain by reporting the results of an investigation involving measurements of the hemispherical pattern of the field scattered by a random soil surface. S-band polarimetric radar scattering measurements have been carried out on a random surfaces of different characterized. The measurements were performed by a 3.2-GHz fully polarimetric radar system with transmitter and receiver modules mounted on Semi-circular orbit. The acquired data were analyzed to determine the angular sensitivities of several attributes of the scattered field, including backscattering scattering coefficients of different polarization, different soil surface parameters. In order to further improve the system's precision, many independent samples were measured by turntable rotation, and show that the indoor radar scattering measurements system was effective and accurate for study the mechanism of random rough surface scattering.